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ISSN 1984-4433

2019 | Volume 11 | Número 1

Uma publicação do Instituto Internacional de Cromatografia www.iicweb.org

Scientia Chromatographica EDITOR-IN-CHIEF

FERNANDO MAURO LANÇAS Universidade de São Paulo Instituto de Química de São Carlos 13560-970 São Carlos (SP) - Brasil editor@scientiachromatographica.com EDITORES ASSOCIADOS

MARIA EUGÊNIA QUEIROZ

RENATO ZANELLA

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preparo de amostras

JOSÉ MANUEL F. NOGUEIRA

ISABEL C. S. FONTES JARDIM

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CORPO EDITORIAL CONSULTIVO

Daniel Armstrong – EUA Dietrich von Bauer – Chile Fábio Augusto – Brasil Fátima Dutra – Brasil Flávio Leite – Brasil Frank Svec – EUA Harold McNair – EUA Humberto Gómez – México Isabel Cristina Sales Fontes Jardim – Brasil Jailson B. de Andrade – Brasil Janusz Pawliszyn – Canadá Kiyoratsu Jinno – Japão Luigi Mondello – Itália Marcos Eberlin – Brasil Marina Tavares – Brasil Milos Novotny – EUA Milton Lee – EUA Norberto Peporine Lopes – Brasil Phillip Marriott – Austrália Pierina Bonato – Brasil Quézia Cass – Brasil Renato Zanella – Brasil

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ENDEREÇO DO PERIÓDICO

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Ficha catalográfica elaborada pela Seção de Aquisição e Tratamento da Informação do SBI/IQSC Scientia Chromatographica / Associação Internacional de Cromatografia. - vol.11 n.1 (jan./mar. 2019). São Carlos: Associação Internacional de Cromatografia, 2019.

Trimestral ISSN 1984-4433 1. Cromatografia. 2. Lanças, Fernando Mauro, editor chefe.

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Scientia Chromatographica 2019; 11(1):3 Instituto Internacional de Cromatografia ISSN 1984-4433

SUMÁRIO

Editorial.....................................................................................................................................................................................................................5

CE Capillary electrochromatography (CEC): recent materials for capillary column preparation, applications, and future perspectives........................................................................................................................7 Bruno Henrique Fumes, João Victor Basolli Borsatto, Fernando Mauro Lanças

HRGC Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica...........21 Jane Jesus da Silva Moreira, Jair Sebastião da Silva Pinto, Thais Camarotto Oliveira, Fernando Mauro Lanças

SAMPLE PREPARATION A novel coffee oil extraction procedure employing pressurized solvents................................................28 Jair Sebastião da Silva Pinto, Suzana Lucy Nixdorf , Marcela Jordan-Sinisterra , Fernando Mauro Lanças

Eventos 2019.......................................................................................................................................................................................................34 Instituto Internacional de Cromatografia.................................................................................................................................................39 Bookstore..............................................................................................................................................................................................................40 Normas para Publicação.................................................................................................................................................................................41

Scientia Chromatographica 2019; 11(1) 3

Scientia Chromatographica 2019; 11(1):5 Instituto Internacional de Cromatografia ISSN 1984-4433

EDITORIAL

Scientia Chromatographica Volume 11, Número 1 de 2019

Iniciando o Volume 11 do Scientia Chromatographica, este número está recheado de assuntos inovadores e, infelizmente, de menor prática em nosso país. O primeiro artigo apresenta uma revisão atualizada da Eletrocromatografia Capilar (CEC, Capillary Electrochromatography), um híbrido entre a cromatografia líquida capilar e a eletroforese capilar. Trata-se de uma ferramenta analítica bastante poderosa, ainda pouco conhecida e praticada, mas que apresenta excelentes resultados analíticos. Seu emprego mais marcante no momento é na análise de medicamentos, porém já surgem aplicações em outras áreas. O segundo artigo trata da extração de óleo de café através da extração sub-crítica, uma ferramenta de extração empregada em escala industrial para produção, e em escala de laboratório para o preparo de amostras. Apesar de sua simplicidade de execução e excelentes resultados, é uma técnica ainda pouco conhecida e, por isso, sub-utilizada. O equipamento empregado, e descrito em vários outros artigos do grupo, assemelha-se bastante com o dispositivo projetado, construido e empregado no artigo seguinte. O outro artigo enfatiza o uso de um sistema projetado no laboratório para a técnica denominada Extração com Solventes Pressurizados. Sua aplicação na extração de triacilglicerídeos de café é demonstrada através da análise dos produtos através de cromatografia gasosa de alta resolução em temperaturas elevadas. O sistema utilizado, com pequenas e simples adaptações, pode ser empregado em várias técnicas como SFE, sub-SFE, ASE, PSE, e outras.

Esperamos que os artigos tragam novas idéias de pesquisa aos leitores, e que sejam de utilidade em seu trabalho.

Fernando M. Lanças Editor

Scientia Chromatographica 2019; 11(1) 5

Scientia Chromatographica 2019; 11(1):7-20 Instituto Internacional de Cromatografia http://dx.doi.org/10.5935/sc.2019.004 ISSN 1984-4433

CE

Capillary electrochromatography (CEC): recent materials for capillary column preparation, applications, and future perspectives Bruno Henrique Fumes, João Victor Basolli Borsatto, Fernando Mauro Lanças Universidade de São Paulo, Instituto de Química de São Carlos. 13560-970 São Carlos (SP), Brasil

Resumo

A eletrocromatografia capilar (CEC) é uma variação da técnica denominada eletroforese a qual emprega uma coluna capilar contendo, em seu interior, uma fase estacionária similar àquelas empregadas em cromatografia líquida. O desenvolvimento de novas colunas para esta técnica tem recebido expressiva atenção, predominando fases baseadas em grafeno e seus derivados, líquidos iônicos (ILs) e polímeros impressos molecularmente (MIPs). A presente revisão discute os avanços recentes no preparo de novos materiais para CEC, sua principais aplicações e tendências futuras da técnica.

Palavras chaves: grafeno, óxido de grafeno, líquidos iônicos, MIP, tecnologias de prepare de colunas, eletrocromatografia capilar

Abstract

Capillary electrochromatography (CEC) is a variation of the electrophoresis technique that employs a capillary column filled with a stationary phase. Similarly, as liquid chromatography, the development of new columns started to receive attention from scientists interested in instrumentation, and some materials have been tested in open tubular (OT) and monolithic columns. Among the materials that have received particular attention in CEC column fabrication, are highlighted: graphene oxide (GO)/graphene, ionic liquids (ILs) and molecularly imprinted polymer (MIP). The present review discusses some historical aspects of CEC, column technologies, and new materials (GO/graphene, ILs, and MIP) in column preparation focusing on their synthesis. Additionally, properties and applications in pharmaceutical, proteomic, environmental, and food analysis covering the period of 2012-2020.

Keywords: graphene, graphene oxide, ionic liquid, MIP, column technologies, capillary electrochromatography Highlights: new materials used in column development - graphene, graphene oxide, ionic liquids, MIP - open tubular and monolith column technologies – applications in pharmaceutical, food, proteomics, and environmental separations.

Abbreviations: BSA, bovine serum albumin; CEC, Capillary electrochromatography; CNTs, carbon nanotubes; CPTMS, choloropropyltrimethoxysilane; EDMA, ethylene dimethacrylate; EOF, electroosmotic flow; G, graphene; GO, graphene oxide; HETP, height equivalent theoretical plate (HETP); IL, ionic liquid; LC, liquid chromatography; LMA, lauryl methacrylate; MIP, molecularly imprinted polymer; MNPs, magnetic nanoparticles; ODS, octadecylsilane; OT, open tubular; PAHs, polycyclic aromatic hydrocarbons; PANI, polyaniline; PDA, polydopamine; poly-TRIM, polytrimetilpropane trimethacrylate; RSD, residual standard desviation; SAX, strong anionic exchange; TMOS, tetramethoxysilane; XPS, x-ray photoelectron spectroscopy; XRD, x-ray diffraction.

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Fumes B. H., Borsatto J. V. B., Lanças F. M.

1. CEC Historical aspects The concept of capillary electrochromatography emerged with the Pretorious’ experiments in 1974 by applying a electrical potential instead of a pressure to pump the mobile phase. [1] The main problem found was column heating, a consequence of the use of an HPLC column with poor heat dissipation. In 1983 Jorgenson e Lukacs [2] conducted the first separation using graphite electrodes applying 30kV of voltage in a capillary column with 170 ¾m (internal diameter) packed with silica Partisil-10 ODS-2, with on-column fluorescence detection. The main advantage of this work was the possibility of applying high voltages, which contributes to faster separation. This was possible because of the use of a capillary column that dissipated better heat caused by the Joule heating effect. Following this work, Knox e Grant [3] studied the fundamental aspects of CEC, such as electroosmotic flow profile (EOF). EOF relation with particle size and a decrease in Joule heating effect when the capillary column is used were evaluated. All these works showed that better separation could be achieved using flow generated by potential difference instead of pressurized flow.

2. Column technologies and new materials used as stationary phases

It is well known that capillary columns in CEC are required due Joule effect. There are three column technologies used nowadays: packed columns, open tubular columns, and monolithic columns. These columns have vantages and advantages among them, and of course, materials used in column design are receiving special attention in the last years. The critical point is that in the period that this review comprises (2012-2020) almost all publications evaluated in several application fields (pharmaceutical, proteomic, food, environmental, etc.) employed either monolith or open tubular columns. This is because these columns do not use frits, so bubble formation 8

Capillary electrochromatography (CEC)

in the system will decrease, as will be discussed in the next topic. Besides, heat-dissipation is better in these column types.

New materials used in column packing can improve selectivity, peak capacity, height equivalent theoretical plate (H), and, consequently, obtain better resolution. It was also noted that some materials had received particular attention in column development. Among these materials graphene (G), graphene oxide (GO), ionic liquid (IL), and also MIP, with few articles published in this period, are significant materials to obtain selective columns for particular compounds class. This subject will also be discussed in this review.

2.1. Packed columns There is no commercially available frit for capillary columns, so it is necessary to use lab-made approaches.

In situ, sintering is a useful alternative for frits if the material presents Si-OH groups. However, frit fabrication is a concern that deserves special attention because this process will affect column performance and also can be responsible for burble formation in the CEC system. [4] The photopolymerization in UV is another alternative.

Using suitable monomers, however, radiation can change the silica properties near the frit, which will also contribute to bubble formation. [5] The use of magnetic nanoparticles (MNPs) ferrite-based and reduced capillary column diameter in column extremity is another strategy. [6]

2.2. Open tubular columns Open tubular (OT) columns are produced by forming a thin film of stationary phase on the column capillary walls. This column configuration has a better heating dissipation compared with a packed and monolithic column, but has lower sample capacity. The stationary phases used in OT columns are classified into four types: chemically bonded, physically or dynamically adsorbed, organic polymers based, and coated by the sol-gel process.

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Fumes B. H., Borsatto J. V. B., Lanças F. M.

The organic polymer chemical bond onto the capillary silica wall forms the first type; the second phase-type use electrostatic interactions between the capillary and with a binder group; the third type involve a polymerization process during the capillary column preparation; a sol-gel process is the typical one representing the fourth and last type of phase. These processes are similar to monolithic column fabrication, but only a small amount is deposited in the capillary wall [7,8].

2.3. Monolith columns Monolithic capillary columns consist of a porous bed of a solid stationary phase with network channels in which mobile phase flows. This column type has macrospores (diameter 2 to 50 nm) and mesopores (around to 2 nm diameter). The use of monolith is a good alternative for replacing the packing material because it does not require frit. These columns are prepared by in situ polymerizations. The phases that form the monolith are divided into two categories: silica-based monoliths and organic polymers based monoliths. [9,10]

2.4. Advanced materials used in capillary column preparation, properties, and synthesis strategies.

2.4.1. Graphene and graphene oxide Graphene was discovered in 2004; this carbon nanomaterial has shown excellent properties for analytical sample preparation, columns preparation, and other applications. [11] This includes extraordinary electronic, thermal and mechanical properties, ultrahigh specific surface area, good thermal conductivity, electric mobility of charged carriers, excellent optical transparency, high Young’s modulus values, and fracture strength.

Furthermore, graphene is inexpensive and easily synthesized. [11] The nanosheet graphene morphology allows adsorption in both surfaces, and this can contribute to a better separation, been an advantage in comparison with

Capillary electrochromatography (CEC)

carbon nanotubes and fullerene, for example. Nanotubes and fullerenes can present steric hindrance, blocking the possibility of the target compounds access their inner surface [12]. The main important application of graphene in separation using CEC is the separation of molecules with a delocalized π-electron system. This provides strong affinities for molecules with aromatic rings such as organic pollutants, drugs, and some biomolecules. There is also the possibility to functionalize graphene through GO. [11] Many synthetic routes can be used to obtain graphene and GO starting with graphite. Gengle et al.[13] published a review addressing this theme. The primary method to obtain is by reducing graphene oxide; the most useful method to obtain graphene oxide is the Hummers 7 method, which follows a chemical exfoliation process. The main synthesis steps involve graphite oxidation by KMnO4, H2SO4 and NaNO3, followed by chemical exfoliation of the formed graphite oxide to obtain graphene oxide. Finally, the oxide reduction to graphene, using most commonly hydrazine, completes the sequence. A concern that must be considered is that graphene can agglomerate if dried in the wrong way (atmosphere dry). To prevent this, it is necessary to use freeze-drying under vacuum; this will prevent graphene nanosheets agglomeration. [11] If there is a need for separation of more polar compounds, GO can be used after being prepared using the same method proposed by Hummers [14], but escaping the last step (GO reduction). The same dry process can be used to prevent GO agglomeration, but if dried at room temperature, the GO agglomeration is expected to be lesser than for graphene nanosheets due presence of carbonyl and hydroxyl groups in the GO structure.

2.4.2. Ionic Liquids (ILs) ILs are liquid salts at room temperature (25° C), whose melting point is lower than 100 °C. The ILs stand out due to the physicochemical properties derived from their molecular structure. Their molecular structure consists of organic cations or/and anions derived from Lewis bases (nitrogen and phosphorus) donor atoms. Some

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Fumes B. H., Borsatto J. V. B., Lanças F. M.

examples of cations ILs are imidazolium, pyrrolidinium, and polyatomic anions containing different inorganic or organic anions as tetrafluoroborate, hexafluorophosphate, bromide). [15,16] ILs have attracted interest in sample preparation and analytical separations due to the possibility of adding different substituents into the IL structure, thus tailoring their hydrophobic or hydrophilic abilities. The approaches used in column fabrication are supported, immobilized, attached, and surface-confined ILs. IL supported can combine properties of IL with solid supports; the most usable are graphene, CNTs, fused silica or particles, and magnetic nanoparticles. This supported ILs allow different types of interactions such as ion-exchange (inorganic anions), hydrophobic interactions, electrostatic interactions, strong hydrogen bonding, and π-π, which contributes and improve the separation process. [16] The main limitation of this approach is to bond the IL onto the support. The most used support is silica due to the difficulty to immobilize ILs in the surface of inert materials; this is an advantage if taken in consideration that capillary column used to fabricate CEC columns are made of silica. [16]

2.4.3. Molecularly imprinted polymers (MIP) The use of molecular imprinting arose from the molecular recognition defined as the ability of a molecule that binds to another to complement the first form, based on selective interactions such as antigen-antibody and enzymesubstrate. [17] This is responsible for the main advantages of using MIP as a stationary phase. The existence of selective sites is fundamental for the interaction between the monomer and the template molecule during the polymer synthesis. [18] For these aspects, MIPs exhibit a very high specificity for target compounds or compounds class.

Capillary electrochromatography (CEC)

Mosbach synthesized a non-covalent organic polymer different from the process developed by Wuff. [19] Since then, the imprinted materials have been widely studied and applied in many areas of chemistry. In CEC column preparation it is not different, although the publications in the last five years shows a clear preference for the use of graphene and ILs derivatives.

Three approaches can be used in MIP syntheses: covalent, non-covalent, and semi-covalent. The covalent method forms reversible covalent bonds between the monomers and the template. However, to remove the template from the resulting MIP, cleavage of the covalent bonds is required, and this can damage the polymer formed, and consequently, reduction of selectivity can be observed.

In this type of material, the application becomes restricted as there are not many functional monomers that can be used in the syntheses. [20] The non-covalent approach involves the formation of non-covalent interactions between monomers and the template. These interactions are ionic, hydrophobic, or hydrogen bond types. This method for the preparation of MIPs is the most commonly used due to the incorporation and removal of the template without the formation and breakage of chemical bonds, an advantage over the first method. Besides, a wide variety of functional monomers can be used for selective interactions with the sites of the molecules of interest. However, this method also has lower selectivity because a balance occurs during the interaction of the monomer with the template in the synthesis process. Thus, it is necessary to use an excess of monomer to ensure the complex formation, and this factor leads to the formation of the MIP selective sites due to the presence of free functional monomers. The semi-covalent approach combines the advantages of two methods just described. Initially, covalent and non-covalent bonds are formed during the molecular recognition of the analytes.

[19]

Wulff and Sarham developed the first approach to molecular recognition in 1972; these authors described the synthesis of a covalent organic polymer with selective sites for glyceric acid enantiomers. In 1981, Arshady and 10

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Capillary electrochromatography (CEC)

3. Applications of CEC focusing materials used in capillary columns and applications covering the period of 2012-2020.

The applications that were focused in this review comprise the period of 2012-2020 (pre prints and accepted papers as well) and intend to show possible applications of the discussed materials (G, GO, IL, and MIP) in CEC. The division of topic was done focusing on pharmaceutical, proteomic, environmental, and food applications.

3.1. Pharmaceutical application CEC’s relevant applications that comprise pharmaceutical applications using different materials in CEC capillary columns are shown in Table 1. It can be noted that the works in this area of application focus on monolithic and OT columns. The highlighted material in this section is the use of graphene and MIP. Unfortunately, in this review it was not find any work that uses ILs for these applications.

Table 1. Recent column/material fabricated for CEC applications in pharmaceutical field.

Column/materials

Applications

Year

Monolithic MIP column

Chiral separation of amlodipine

2012

[21]

Silica monolithic column chemically modified with L-pipecolic

Chiral separation of dansyl amino acids

2012

[22]

OT-BSA conjugated with GO/Fe3O4

Enantioseparation of L-tryptophan used in antidepressant agent

2013

[23]

Monolith BSA functionalized

Recognition between two of enantiomers pantoprazole and atenolol

2014

[24]

OT-GO funcionalized

Benzhydryl compounds separatation

2014

[25]

OT, GO-MIP

Determination of dopamine, epinephrine, and norepinephrine

2014

[26]

OT, silica sol–gel containing porphyrin-brucine conjugate

Evaluation of oligopeptides, nucleosides, nucleobases and nucleotides

2017

[27]

Polydopamine/Au nanoparticles/ DNA on Chip

Separation of tryptophan enantiomers

2017

[28]

Separation of nefopam, amlodipine, citalopram hydrobromide, econazole, ketoconazole and cetirizine hydrochloride

2020

[29]

OT , GO modified with Maltodextrin

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Lei et al. [30] explored the combination of monolithic design grafted MIP. Polytrimetilpropane trimethacrylate (poly-TRIM) was used as a template, performing the grafting polymerization. To evaluate the monolithic perform, the authors test the column for chiral separation of rac-amlodipine, zopiclone, and ofloxacin.

The authors investigated the temperature effect in the column preparation, concluding that temperatures higher than 60 °C produces an occluded column. The use of different solvents in column preparation (ACN, toluene, and mix of toluene and isooctane) produced columns able to separate enantiomeric mixtures. However, the best results were obtained using toluene/isooctane. The results were also reproducible, showing an RSD lower than 5% for all compounds. This work contributes to showing a secure method to prepare a porogen column for chiral separation and also suggested that more than one solvent can be used in this kind of monolithic column preparation.

Liang et al. [23] proposed an OT column containing bovine serum albumin (BSA)-conjugated graphene oxide– magnetic nanocomposites (GO/Fe3O4) as stationary phase for enantioselective separation of L-tryptophan used as an antidepressant agent. The authors optimized the following CEC conditions: the influence of detection potential, separation voltage, buffer concentration, and pH buffer. These are the most relevant factors to be evaluated

Capillary electrochromatography (CEC)

when developing a CEC method, taking into account that all these factors must be optimized to achieve better separation conditions. The RSD % obtained before method optimization was less than 6%. The main result of this work discussed by the authors was the possibility to conclude that stationary phase GO/Fe3O4/BSA can be packed at any desired position in the microchannel by an externally applied magnetic field, which simplifies the immobilization methodology of proteins in OT-CEC. Furthermore, the GO/Fe3O4/BSA can be regenerated easily, which helps method reproducibility.

Ye et al. [26] prepared an OT capillary column GOMIP coated. Figure 1 represents the schematic procedure to prepare this column. The method used in OT column preparation was the same used to coat CE columns using methacrylic acid and dopamine as a template monomer [31]. Results showed good reproducibility (RSD% lower than 6,2) for all analytes, with an excellent linear range (20,0–200,0 µg/mL). The material characterization was done using x-ray diffraction (XRD); most of the works that synthesize graphene for sample preparation and other applications use this method, sometimes in combination with Raman spectroscopy or x-ray photoelectron spectroscopy (XPS) [32]. The authors of this work also confirmed that EOF is stable in different pH ranges so that this study can contribute to the fabrication of other

Figure 1. Schematic preparation of the GO-MIPs coated capillary. Reproduced by permission from [26] 12

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Capillary electrochromatography (CEC)

MIP templates coated with graphene for other analytical proposed.

3.2. Proteomic applications Recently scientists have moved their attention to proteomic fields identification, quantification, and characterization of the proteins and peptides of a specific biological fluid, cell, or tissue, and the study of their structure, function, and interactions. This interest is due to the expectation that the results obtained in this field can

contribute to clinical diagnosis, treatment, and biomarker discovery, helping to prevent, diagnose, and monitor the evolution of many diseases. [33] CEC can contribute to proteomic analysis, as shown in Table 2, which summarizes recent applications using materials highlighted in this review and other materials used in capillary column preparation. The material that clearly received particular attention in the revised period was ILs, which has more publications in this area, preferably using monolithic columns; some relevant works will be discussed below.

Table 2. Recent column/material fabricated for CEC applications in environmental.

Column materials

Applications

Year

Monolithic - IL (tetramethoxysilane and 3-mercaptopropyltrimethoxysilane)

PAHs, four alkylbenzenes and five phenols

2012

[34]

Silica particles entrapped with monolithic frits

Alkyl benzenes separation

2012

[35]

Monolithic- IL (1-vinyl-3-octylimidazolium chloride, ViOcIm(+)Cl(-))with lauryl methacrylate (LMA)

Alkyl benzenes separation

2012

[36]

Monolithic -GO incorpored in column

Separation of alkyl benzene and PAHs

2012

[37]

Monolithic - organic-silica hybrid

Polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, phenols, inorganic anions and organic acids separation

2013

[38]

Monolithic - (glycidyl methacrylate-co-ethyleneglycol dimethacrylate)

Alkylbenzene separation

2014

[39]

OT – graphene

Alkylbenzene separation (in this case was evaluated different coated strategy)

2014

[40]

Monolithic IL (1-butyl-3-vinylimidazoliumbis[(trifluoromethyl)sulfonyl]imide)

Separation of alkylbenzenes, phenols, anilines and polycyclic aromatic hydrocarbons

2018

[41]

Monolithic, 1-vinyl-3-octylimidazolium bromide (VOI) and styrene

Separation of alkylbenzenes, polycyclic aromatic hydrocarbons, proteins and amino acids

2020

[42]

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Wang et al. [36] proposed an IL monolithic capillary column prepared by thermal free-radical copolymerization of IL (1-vinyl-3-octylimidazolium chloride, ViOcIm+Cl−) together with lauryl methacrylate (LMA) as the binary functional monomers, and ethylene dimethacrylate (EDMA) as the cross-linker in binary porogen. The proportions of reagents used in column the fabrication were optimized and showed, as expected, a remarkable influence in EOF. Some factors that affected the polymerization mixture of cationic monomers, as in IL case, include: the distance of the imidazole groups and the radical position, charge density, ionic strength, and hydrophobic interactions. So, it is also important to evaluate different proportions among reagents to find better conditions. In this work the authors suggested the optimal ratio of ViOcIm+Cl− to EDMA was 60–40% considering of the visual appearance of peak shape (of course a better option is the use of a factorial design to evaluate this). A monolithic column with cationic imidazole groups of ViOcIm+Cl− can generate a stable reversed EOF in a wide pH range. It was demonstrated that the separation mechanism of charged compounds could be a mixed-mode of SAX, and hydrophobic interaction and neutral compounds separations were based on hydrophobic interaction.

Xiau Wang et al. [43] prepared a monolithic column using pyridinium immobilized in silica surface by in situ polymerization in 3-chroropropyl-silica and 4,4’-dipyridyl for hydrophilic interaction. The hybrid material has stable microstructures with a hydrophilic retention mechanism using a mobile phase with a CAN concentration higher than 50%. Stable EOF was observed in 3,0-9,0 range of pH. The combination of this IL supported on a silica surface also can supply other separations mechanisms (hydrogen bond, π-π interactions, and anion exchange). The column was employed in amino acids and nucleotides separation (and also phenol, but this is not the focus in this section), and the number of theoretical plates achieved for nucleic acids was near 164 000. This capillary column approach has great potential to be used for the analysis of polar compounds in CEC. Of course, the comparison with other approaches is necessary to evaluate the best methodology.

14

Capillary electrochromatography (CEC)

Gao et al. [44] produced an OT-CEC column coated with GO using a tentacle-type polymer coating (Figure 2). This approach is also used in other capillary column preparation for CEC [45,46]. This column showed a stable EOF in a wide pH range (4,0-9,0), having a good separation of small neutral molecules, amino acids, and ephedrine– pseudoephedrine isomers with a resolution higher than 2.30 and column efficiency up to over 170 000 plates/m.

The reproducibility in column preparations showed an RSD lower than 7,5%, which is suitable considering that many variables can influence this kind of column preparation. This column was compared with a polymer and GO capillary coated and showed higher theoretical plate numbers and resolution than both. The results showed that this column could be used to provide separation of peptides and other small molecules. The results will be better for polar compounds because GO is better for this kind of separation than graphene (G) due to the presence of hydroxyl groups in the GO surface.

Figure 2. Representation of a GO tentacle-type polymer coating for CEC column. The carbon chains are represented through the green lines.

3.3. Environmental Most applications retrieved in this review that could be employed in the environmental analysis are because column characterization of CEC columns utilizes PAHs and benzene derivatives as chemical probes. The same behavior is observed in the last two applications described as for environmental analysis. The majority of the new columns prepared for being used in CEC utilize ILs follow and graphene oxide/graphene. Table 3 summarizes the applications in this field.

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Han et al. [34] fabricated a monolithic column based on mercaptopropy-functionalized (MP-silica),

prepared by in situ co-condensation tetramethoxysilane and 3-mercaptopropyltrimethoxysilane exploring sol-gel process. The authors used FT-IR and XPS to characterize

Table 3. Recent column/material fabricated for CEC applications in proteomic.

Column materials

Applications

Year

OT - bare gold nanoparticles (GNPs)-based stationary phase

Tryptic peptide fragments of native and glycated proteins, bovine serum albumin (BSA), and human transferrin (HTF)

2012

[47]

Monolithic - IL IL (1-vinyl-3-octylimidazolium chloride, ViOcIm(+)Cl(-))with lauryl methacrylate (LMA)

Amino acids separation

2012

[36]

Monolithic - (ILs) based on 1-vinyl-3-octylimidazolium

Four proteins separation

2013

[48]

Monolithic-ILs pyridinium-based

Nucleotides, nucleic acid bases, and nucleosides and nicotines

2013

[43]

OT - polydopamine (PDA) coating as an adhesive

Proteins separation in biological sample

2013

[49]

OT - histone deacetylase

Apigenin, naringenin, luteolin, and kaempferol characterization

2013

[50]

OT - APAT-DVB heptakis(2,3-di-O-acetyl-6-O-sulfo)β-CD

D-and l-aspartic acid, d- and l-tyrosine and d-and l-lysine

2014

[51]

monolith BSA functionalized

Tryptophan enantiomers separation

2014

[24]

OT - BSA/ PDA/GO

Separation of chiral amino acids tryptophan and threonine

2014

[49]

OT - N-phenylacrylamide-styrene copolymer-

Separation of anomers of glucose and structural isomers of maltotriose.

2015

[52]

OT – GO

Amino acids separation

2015

[44]

OT, ctaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes and 4-aminophenyl disulfide

Tryptic digest of mouse liver protein

2017

[53]

Monolithic, 1-vinyl-3-octylimidazolium bromide (VOI) and styrene

Separation of alkylbenzenes, polycyclic aromatic hydrocarbons, proteins and amino acids

2020

[42]

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the column, which generate a stable EOF in a wide range of pH (3.0–8.0). The column’s evaluation was done separating 4 alkylbenzenes, and 5 phenols derivatives and 3 PAHs, with an RSD lower than 6% for different columns, showing the excellent reproducibility of the synthesis method.

Unfortunately, the authors did not test these aspects for other compounds (alkylbenzenes and phenols derivate), which could supply better information on the column behavior for different compounds.

Zhang et al. [40] fabricated an OT column for CEC coated with graphene, with a fascinating strategy used, different from that one just cited in this review. The authors first functionalized the capillary surface with polydopamine (PDA), then GO introduced reacting covalently with PDA. PDA’s modification efficiency, a conductive polymer, was improved, introducing polyaniline (PANI) to be a sub-layer; PDA was then introduced followed by GO to generate a multilayer capillary column coated with GOPDA-PANI. The PANI used as a sub-layer improved the capillary separation column. The EOF of the different columns was evaluated by changing the mobile phase pH using thiourea as the EOF marker. For GO-PDA-PANI, the EOF is stable in a pH ranging 4,0-7,0 as shown in Figure 3. The separation efficiency was done evaluating alkylbenzenes separation, and theoretical plate numbers were higher than 130 000 for benzene, and RSD was lower than 6,2% for different columns.

Thang et al. [38] developed a CEC monolithic column with two separation mechanisms (mixed mode) using sol-gel tetramethoxysilane (TMOS) and c-choloropropyl-trimethoxysilane (CPTMS) as monomers followed by a post-modification using 4,4-dipyridine.

The mechanism of separation exhibit hydrophobic, π-π and anion-exchange interactions, which can help in an improvement in selective mainly for the compounds used in this case: PAHs, alkylbenzenes, phenols, inorganic anions, and organic acids. The column generated a stable EOF and reversed at acidic pH (3-6) due to the pyridinium groups on the surface of the stationary phase; RSD for different monolithic columns were less than 5% for all compounds. Furthermore, the monolithic column showed 16

Figure 3. Illustrative representation of the influence of buffer pH on the EOF mobility for the capillaries. Experimental conditions: 10 mM CH3 COONa (pH 4–6), 5 mM Na2 HPO4 (pH 7–9); separation voltage, 20 kV; injection, 30 mbar × 3 s; detection wave, 210 nm; capillary column, 60.5 cm (52 cm effective length) × 50 μm i.d. Thiourea was used as EOF marker. Reconstructed from[40].

a uniform, monolithic matrix tightly bonded onto the inner capillary wall, and the dipyridinefunctionalized monolithic column showed multiple separation capabilities to be used in neutral and anionic compounds.

3.4. Food There are still only a few publications about the determination of contaminants or other compounds in food

by CEC in the period covered by this review, as shown in Table 4. The work that deserves special attention here is the application developed by OuYang et al. [54].

The innovative approach used for these authors used a pressurized CEC system that reminds a pressure pump used in HPLC. The significant advantage that the use of pressure can provide is to improve the EOF reproducibility, which is cited as one of the main problems when using CEC systems.

Another point here is that the use of a packed capillary column was not cited yet during the discussion because of the disadvantages that it has when compared to OT and monolithic columns, considering the practical difficulties of reproducing frits sintering and flow reduction. The method proposed by these authors is beneficial in terms of lesser solvent consumption, high separation efficiency, Scientia Chromatographica 2019; 11(1):7-20

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Capillary electrochromatography (CEC)

and rapid analysis than flow generated by the potential differences.

Table 4. Recent column/material fabricated for CEC applications in food contaminants analysis.

Column/materials

Applications

Year

Monolith, core-shell silica nanoparticles Fe(3)O(4)@SiO(2)/NH(2) Packed, (Electropak™, C18, ODS, 3 μm column)

Organic acids separation in complex samples

2012

[30]

Determination of Flumequine and Oxolinic Acid Residues in Aquatic Products

2014

[54]

Monolith, organic-inorganic hybrid MIP

Organophosphorus pesticides determination in food sample

2014

[55]

Monolith, Poly(vinylimidazole-co-ethylene dimethacrylate)

Nitrate and nitrite in vegetables

2019

[56]

4. Concluding Remarks

Regarding the aspects of new analytical techniques, CEC has the most considerable importance to the pharmaceutical industry, especially in the analysis of neutral and acidic compounds, being limited for the separation of strongly alkaline compounds. This may be a paradox since many pharmaceutical industry products contain basic functions such as amines, which are often strongly alkaline, being undoubtedly an obstacle to the evolution of technique. Although some progress has been achieved by adding additives to the mobile phase, there is still a need for continued progress.

In the past, most capillary columns used were made from fused silica, but we can observe in this review that this is a trad off. The use of OT and monolithic column shows an advantage mainly because there is no need for sinterized frit in this type of column, which prevents bubble formation in the system. The study of different materials used for column fabrication has been showing a significant

interesting field for researches, with ILs and graphene/GO as the most studied materials in the period covered.

A concerning point in the CEC technique is related to instrumentation. Although CE equipment can be adapted, control of EOF is difficult in these conditions. One way of solving this problem would be to use a hydraulic flow to overcome flow generated electrically, improving the reproducibility of the technique as just cited in this review. [54] This issue can be part of a μ-LC-CEC, but manufacturers have not shown interest in this system. [57].

Acknowledgments

This project was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors are grateful to FAPESP (Grants 2017/02147-0, 2015/15462-5, and 2014/07347-9) and CNPq (307293/2014-9) for the financial support provided.

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Scientia Chromatographica 2019; 11(1):21-27 Instituto Internacional de Cromatografia http://dx.doi.org/10.5935/sc.2019.005 ISSN 1984-4433

HRGC

Fractionated subcritical carbon dioxide extraction of triacyglycerides from coffea arabica

Jane Jesus da Silva Moreira1, Jair Sebastião da Silva Pinto2, Thaís Camarotto Oliveira3, Fernando Mauro Lanças3* Departamento de Engenharia de Alimentos, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n, 49100-000, São Cristóvão, SE, Brazil.

1

Escola Superior de Agricultura Luiz de Queiroz-ESALQ/USP, 13418-900 Piracicaba-SP, Brazil.

2

Universidade de São Paulo, Instituto de Química de São Carlos, 13560-970 São Carlos (SP). Brazil. Corresponding author: F.M. Lanças, flancas@iqsc.usp.br 3

Resumo

Uma das variedades de café comercialmente importante é o Coffea arabica L., desde que muitas bebidas comerciais de café são feitas a partir de grãos de arábica ou suas misturas. Consequentemente, a variedade arábica tem preço mais alto. Oxidação de lipídeos em café armazenado por muito tempo tem sido reportada com a perda de qualidade do café. Embora o comportamento dos lipídeos do café durante o armazenamento não tenha sido sistematicamente examinado, poucos estudos têm sido reportados sobre a liberação de ácidos graxos. Análise química pode ser aplicada para o controle de qualidade da fração lipídica. Usando essa abordagem, um método para análise dos triacilglicerídeos (TAG) por cromatografia gasosa de alta resolução a alta temperatura com detector de ionização em chama (HT-HRGC/ FID) depois da extração com fluido sub ou supercrítico (SFE/SbFE), foi desenvolvido.

A extração foi executada com um extrator SFE, construído em nosso laboratório, com amostra de óleo de café arábica. A composição encontrada dos TAG do óleo de café arábica brasileiro foi de T52 a T56.

Palavras chaves: Café arábica, Extração com fluido subcrítico, Química analítica verde (GAC)

Abstract

A commercially essential coffee specie is Coffea arabica L. Most commercial coffee beverages are made from arabica beans or its blends. Consequently, the arabica variety has a higher price. Oxidation of lipids in coffee stored for a long time has been reported with the loss of coffee quality. Although the behavior of coffee lipids during storage has not been systematically examined, few studies have been reported on the release of fatty acids. Chemical analysis can then be applied to the quality control of the lipid fraction. Using this approach, a method for the analysis of triacylglycerides (TAGs) by high-temperature high-resolution gas chromatography with flame ionization detection (HT-HRGC/FID), after supercritical or subcritical fluid extraction (SFE/SbFE), was developed. The extraction was performed with a homemade SFE in the Coffea arabica L. oil sample. TAGs composition of Brazilian Coffea arabica oil was found to go from as T52 to T56.

Keywords: SFE; HT-HRGC, Coffea arabica oil, Subcritical fluid extraction, Green Analytical Chemistry (GAC)

Scientia Chromatographica 2019; 11(1)

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Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

1. Introtuction The goal to reduce the use of hazardous organic solvents in analytical extractions has contributed in the last few years to the development of new technologies using less solvent than standard extraction procedures (1). Among these techniques for rapid, efficient, and costeffective means of sample treatment, pressurized fluids have received particular attention. This class of techniques has received the broad name of Pressurized Fluid Extraction (PFE) (2). Including in this class of extraction methods are Supercritical Fluid Extraction (SFE), Sub-Critical Fluid Extraction (SbFE), and Accelerated Solvent Extraction, ASE. An ideal extraction method should be fast, simple, and inexpensive to perform. It should yield quantitative recovery of the target analytes without loss or degradation, besides providing a sample that is immediately ready for analysis without additional concentration or class fractionation steps(3,4). Unfortunately, classical liquid solvent extraction techniques frequently fail to meet these goals. They often require several hours- or even days- to perform, result in a diluted extract, and may not result in a quantitative recovery of the target analytes. Recent concerns about the hazardous nature of many commonly used solvents, the costs and environmental dangers of waste solvent disposal, and the emission of hazardous solvents into the atmosphere have led to the development of alternative extraction methods(5). In this context, PFE, the technique based on the use of pressurized fluid as leaching agents, is a tool to overcome the difficulties of solid sample extraction (6,7).

The benefits of PFE, versus conventional techniques, result from the accelerated kinetic desorption processes for the analytes from the matrix. The rapid diffusion of analytes in the fluid and the fluid solvation power (8–10), has led to PFE being proposed as an alternative to conventional liquid solvent extractions such as Soxhlet and ultrasonic extractions.

22

The analytes are better extracted at lower temperature conditions, thus increasing the extraction selectivity. In this case, the subcritical fluid condition can be explored (11). This extraction condition offers some advantages over supercritical CO2 conditions for selected compounds, especially for triacylglycerols (TAGs). The extraction is usually selective to TAGs in a complex matrix such as coffee oil. Brazil stands out as the world’s largest coffee producer, with the Arabica species responsible for 75% of its production (12). Although coffee oil has commercial importance, few studies have been carried out on the undesirable changes in lipids due mainly to the hydrolysis of triacylglycerols during the storage of the seeds with the release of free fatty acids, in turn, are oxidized (13–15). Degradation of free amino acids, sugars, and oxidation of lipids in coffee stored for a long time has been reported along with the loss of Brazilian coffee quality. An increase in free fatty acid content was associated with enzymatic activity due to long storage periods in subtropical conditions (13).

The High-Temperature High-Resolution Gas Chromatography (HT-HRGC) used to analyze high molecular mass compounds is preferable than conventional Gas Chromatography (16). Among many other HT-HRGC/ FID features, it does not require derivatization of the sample before the injection, permitting direct analysis of the TAGs extract(17,18).

In this context, this work aimed to study the feasibility of performing PFE using a home-made SFE instrument (19), for the extraction of TAGs from coffee oil, a complex matrix, using supercritical and subcritical CO2 and further analysis of these extracts by HT-HRGC/FID.

2. Experimental 2.1. Solvents and Materials All reagents and solvents were analytical grades.

Carbon dioxide was from AGA (São Paulo, Brazil). Silica Scientia Chromatographica 2019; 11(1):21-27

Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

gel G 60 and n-hexane from Merck (Rio de Janeiro, Brazil).

FAMEs and standard TAGs were from Sigma (St. Louis, MO, USA).

2.2. SFE/SbFE of coffee oil.

Pure and modified supercritical carbon dioxide are suitable extraction media for many lipid materials such as vegetable oils, fatty acids, fatty acid esters, phospholipids, triacylglycerol, and tocopherols (11).

The home-made SFE device used in this work consists of a high-pressure pump, extraction cell, restrictor, collection vial, tubes, and valves. The extraction cell has a volume of 2 mL, made from an empty stainless steel liquid chromatography column. A capillary fused silica restrictor

(30 cm x 0.05 mm i.d) was used to adjust the flow rate, maintain constant pressure, and transfer the extract into the collection device. To avoid the loss of volatile extracted analytes, the 10 mL collection vial containing n-hexane was maintained refrigerated with cooled water. The fluid used was CO2 (carbon dioxide).

Sample of Coffea arabica L. oil, in triplicate, obtained from the toasted seeds was a donation from Dr. Suzana Nixdorf of the University of Londrina, Brazil, and was adsorbed in silica gel (20). In the extraction cell, 1 g of silica saturated with coffee oil sample is loaded. To optimize the PFE conditions, different temperatures and pressures were evaluated. The extraction was performed under both supercritical and subcritical conditions, as shown in Table 1, and the required extraction time was 25 min.

Table 1. Supercritical and subcritical fluid extraction conditions for triacylglycerides from coffee oil.

PSE condition

T (°C)

Pressure extraction (atm)

Density (g/L)

E-1

60

100

300

E-2

60

200

730

E-3

60

300

830

E-4

100

300

665

E-5

0

300

1050

2.3. Analysis of the extracts obtained through SFE and SbFE After extraction, the contents of the vials were dried. The samples were prepared at 0.10 mg/mL of the oil in n-hexane as solvent and subjected to HT-HRGC/FID analysis.

2.4. HT-HRGC/FID Analysis.

The chromatographic analyses were performed on a Hewlett-Packard 5890 Series II Gas Chromatograph with a split injector at 370 °C and a flame ionization detector (FID) at 380 °C. The injection volume was 1 µL, and the split ratio was 1:8. Hydrogen was employed as carrier gas at a pressure of 6 psi. A 9 m x 0.25 mm x 0.08 µm Croma5-HT (5% phenyl, 95% methyl polysiloxane bonded phase) capillary column, coated in-house, was used with

Scientia Chromatographica 2019; 11(1):21-27 23

Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

temperature programming from 280 °C for 1 min, then increased by 4 °C min-1 to 380 °C, and maintained at this temperature for 5 min. The data were collected with an HP 5396 A integrator.

The identification of the TAGs was made by comparing the retention times of the components of interest with the retention time of the triolein (T54) analytical standard.

3. Results and Discussion

The SFE/SbFE was carried out with CO2 in both supercritical conditions (60° C, and 100, 200 and 300 atm; 100° C and 300 atm) and subcritical conditions (0° C and 300 atm). Complete extraction could be achieved in less than 25 min.

The results obtained (Figure 1 and Figure 2), show that increasing the density of carbon dioxide results in increasing the solvation power of the extractant solvent, allowing a fractionated extraction to be conducted.

Figure 1. Fractions of TAGs obtained in PFE were carried out with CO2 in supercritical conditions: temperature 60° C and 100, 200, and 300 atm at pressure.

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Figure 2. Fractions of TAGs obtained in PFE were carried out with CO2 in subcritical conditions: temperature 0° C and 300 atm at pressure.

In the literature, it is described that the obtainment of different classes of compounds is challenging due to the proximity of the extraction regions, producing, in many cases, a mix of the distinct phases (21).

Figure 3. HT-HRGC-FID chromatogram of a profile of coffee oil triglycerides by HT-HRGC-FID. Scientia Chromatographica 2019; 11(1):21-27

Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

In our case, the complexity of the intact coffee oil sample can be observed in the chromatogram of Figure 3.

The first extract fraction (E-1, 100 atm, and 60 °C), shown in Table 1, corresponds to a 300 g/L of carbon dioxide density. This region presents lower solvation power; on the other hand, high selectivity (21) produces an extraction of the essential oil with high volatility.

Increasing the pressure to 200 atm (E-2) at a constant temperature (60 °C), the carbon dioxide density increasing to 730 g/L, allowing an extraction with a higher potential of solvation. The extraction condition E-3 (300 atm, 60 °C, 830 g/L) and E-4 (300 atm, 100 °C, 665 g/L) presented similar lipid composition presented free fatty acids and monoacylglycerides, without TAGs selectivity. This similarity between E-3 and E-4 was due to a little difference in carbon dioxide’s solvation power.

The E-5 condition (300 atm, 0 °C, 1050 g/L) was a better experimental point (Figure 4). Due to the soft temperature condition, lower vapor pressure, and high selectivity to TAGs compounds, the extract obtained presented TAGs as a majority of compounds and traces of

the free fatty acids mono- and possible diacylglycerides, preserving the sample of the probable thermal degradation during the analysis.

The HT-HRGC E-5 fraction analysis shows an average area of 21.8 ± 1.1% in the three TAGs groups (T52 at T56). The advantage of PFE in subcritical conditions with a temperature of 0 C was the reduction of the degradation products. In the case of coffee oils, especially, the degradation by exposure at high temperature for an extended period is a critical point and HT-HRGC it supplies an excellent method of analysis. This occurs because of a change in the original composition of the oil, reducing the concentration of the same compounds as free fatty acids. In extract E-5, obtained under subcritical conditions, the lipid content was determined using both TGAs obtained by HT-HRGC/FID and the sum of all fatty acids, expressed as triacylglycerides. They were obtained from the gas chromatographic (GC) profiles of the fatty acid methyl esters (FAME) analysis, being the result compared with those reported in the literature (13,17,18).

TAGs composition of Brazilian Coffea arabica oil was found to be mainly T52 to T56. The main components of the triacylglycerides comprised an average of 64.3 ± 3.2%.

We were able to analyze the triacylglycerides molecular species by HT-HRGC/FID without derivatization.

The crude coffee oil matrix, in addition to TAGs, presents a large variety of other compounds that might degrade when submitted to the high injector temperature (370° C) and the use of the SbFE before analysis by HTHRGC/FID, eliminating the interferences.

4. Conclusion

Figure 4. HT-HRGC-FID chromatogram of a coffee oil triglycerides extracted at 0° C and 300 atm, with carbon dioxide. T54-triglycerides with 54 carbons.

In conclusion, SbFE combined with HT-HRGC proved to be a viable alternative for the analysis of coffee oil samples. The proposed approach maintain the intact structure of the TAGs’, keeping the apparent profile, while providing a reduction in the amounts of solvents and

Scientia Chromatographica 2019; 11(1):21-27 25

Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

reagents used, and short extraction time, becoming a good example of a Green Analytical Chemistry (GC) method.

support provided for this research and to our laboratory.

The donation of the coffee samples by Dr. Suzana Nixdorf is also appreciated.

Acknowledgment The authors are grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001; to FAPESP (Grants 2019/22724-7 2017/02147-0, 2019/26263-4, 2015/154625, 2014/03765-0 and 2014/07347-9); and to CNPq (307293/2014-9 and 308843/2019-3) for the financial

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Scientia Chromatographica 2019; 11(1):21-27

Moreira J. J. S., Pinto J. S. S., Oliveira T. C., Lanças F. M.

Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica

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[2] Sheibani A, Ghaziaskar HS. Pressurized fluid extraction of pistachio oil using a modified supercritical fluid extractor and factorial design for optimization. LWT - Food Sci Technol. 2008;41(8):1472–7.

[3] Silva RPFF, Rocha-Santos TAP, Duarte AC. Supercritical fluid extraction of bioactive compounds. TrAC Trends Anal Chem.

2016;76:40–51.

[4] Bahruddin S, Basheer C. Sample Preparation Methods for the Analysis of Biogenic Amines. In: Biogenic Amines in Food: Analysis, Occurrence and Toxicity. Royal Society of Chemistry; 2019. p. 212–38.

[5] Płotka-Wasylka J, Rutkowska M, Owczarek K, Tobiszewski M, Namieśnik J. Extraction with environmentally friendly solvents. TrAC Trends Anal Chem. 2017;91:12–25.

[6] Pronyk C, Mazza G. Design and scale-up of pressurized fluid extractors for food and bioproducts. J Food Eng. 2009;95(2):215–26.

[7] Khezeli T, Ghaedi M, Bahrani S, Daneshfar A. Supercritical fluid extraction in separation and preconcentration of organic and inorganic species. In: Soylak M, Yilmaz EBT, editors. New Generation Green Solvents for Separation and Preconcentration of Organic and Inorganic Species. Elsevier; 2020. p. 425–51.

[8] Pinto JSS, Lanças FM. Design, construction and evaluation of a simple pressurized solvent extraction system. J Braz Chem Soc. 2009;20(5):913–7.

[9] Montoya MF, Sánchez FA, Pereda S. Equilibrium in Pressurized Systems (Sub and Supercritical). In: Pereira CGBT-T of PE in FE, editor. Thermodynamics of Phase Equilibria in Food Engineering. Academic Press; 2019. p. 385–418.

[10] McHug M, Krukonis V. Supercritical Fluid Extraction: Principles and Practice. 2nd ed. Butterworth-Heinemann; 1994.

[11] Hamdan S, Daood HG, Toth-Markus M, Illés V. Extraction of cardamom oil by supercritical carbon dioxide and sub-critical propane.

J Supercrit Fluids. 2008;44(1):25–30.

[12] CONAB. Acompanhamento da Safra Brasileira de Café. Monit Agrícola. 2020;6(1):1–62.

[13] Nikolova-Damyanova B, Velikova R, Jham GN. Lipid classes, fatty acid composition and triacylglycerol molecular species in crude coffee beans harvested in Brazil. Food Res Int. 1998;31(6):479–86.

[14] Jham GN, Muller HV, Cecon P. Triacylglycerol molecular species variation in stored coffee beans determined by reverse-highperformance liquid chromatography/refractive index detector. J Stored Prod Res. 2008;44(1):82–9.

[15] Toci AT, Neto VJMF, Torres AG, Farah A. Changes in triacylglycerols and free fatty acids composition during storage of roasted coffee. LWT - Food Sci Technol. 2013;50(2):581–90.

[16] Pereira AS, Padilha MC, Neto FRA. Two decades of high temperature gas chromatography (1983–2003): what’s next? Microchem J. 2004;77(2):141–9.

[17] Pinto JSS, Lanças FM. Hydrolysis of corn oil using subcritical water. J Braz Chem Soc. 2006;17(1):85–9.

[18] Pinto JSDS, Lanças FM. Hydrolysis of azadirachta indica oil using subcritical water and determination of triacylglycerides and fat acids

by HT-HRGC-FID and HRGC-MS. Quim Nova. 2010;33(2):394–7.

[19] Pinto JSDS, Esmeraldo A, Lanças FM. Design and Construction of an on-line SPE-SFE-CGC System. J Braz Chem Soc. 2001;12(2):192– 5.

[20] King JW, Holliday RL, List GR. Hydrolysis of soybean oil . in a subcritical water flow reactor. Green Chem. 1999;1(6):261–4.

[21] Brogle H. CO2 as a solvent: Its properties and applications. Chem Ind. 1982;12:385–90.

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Scientia Chromatographica 2019; 11(1):28-33 Instituto Internacional de Cromatografia http://dx.doi.org/10.5935/sc.2019.006 ISSN 1984-4433

SAMPLE PREPARATION

A novel coffee oil extraction procedure employing pressurized solvents

Jair Sebastião da Silva Pinto 1, Suzana Lucy Nixdorf 2, Marcela Jordan-Sinisterra 3, Fernando Mauro Lanças 3* Escola Superior de Agricultura Luiz de Queiroz-ESALQ/USP, 13418-900 Piracicaba-SP, Brazil.

1

Departamento de Engenharia de Alimentos, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n, 49100-000, São Cristóvão, SE, Brazil.

2

Institute of Chemistry of São Carlos, University of São Paulo. Brazil.

Corresponding author: F.M. Lanças, flancas@iqsc.usp.br

Resumo

No presente trabalho, o óleo de café torrado foi obtido usando dois métodos de extração, sendo um sistema de extração por solvente pressurizado (PSE), proposto no presente trabalho, e o outro um método endossado pela AOAC (Association of Official Analytical Chemists) INTERNATIONAL usando um sistema Soxhlet. Os rendimentos (% p/p) obtidos em cada um deles foram semelhantes, o que permitiu comparar as condições de cada método. Foi demonstrado que no sistema PSE o consumo de solvente (20 mL) e o tempo de extração (20 min) são menores, do que o volume usado no sistema Soxhlet (200 mL) e o tempo de análise usado (480 min).

Isso faz do PSE um método de extração promissor para uso na indústria.

Palavras chaves: Óleo de café, café arábica, extração com solvente pressurizado (PSE), extração acelerada por solvente (ASE), química analítica verde (GAC).

3

28

Abstract

In the present work, roasted coffee bean oil was obtained using two extraction methods, a pressurized solvent extraction system (PSE) and a method endorsed by the AOAC (Association of Official Analytical Chemists) INTERNATIONAL, using a Soxhlet extraction system. The yields (% w/w) obtained in each of them were similar, which allowed the conditions of each method to be compared, demonstrating that in the PSE the solvent consumption (20 mL) and the extraction time (20 min) is less at the volume used in the Soxhlet system (200mL) and the analysis time used (480 min). This makes PSE a promising extraction method for use in industry.

Keywords: Coffee oil, arabica coffee, pressurized solvent extraction (PSE), accelerated solvent extraction (ASE), green analytical chemistry (GAC).

Scientia Chromatographica 2019; 11(1)

Pinto J. S. S., Nixdorf S. L., Sinisterra M. J., Lanças F. M.

1. Introduction The Coffee is one of the agricultural products that over the years have established itself on the list of the most consumed in the world (1). Therefore, the demand for processed coffee products in the international market increases every day, highlighting the aroma and flavor extracts of roasted coffee, sensory attributes that are due to a mixture of a wide variety of volatile compounds obtained during the roasting process (2), qualities widely used in socalled sophisticated foods (3).

Studies have shown that ketones, pyrazines, furans, phenols and pyrrole are the main compounds responsible for the aroma of these roasted coffee beans (4). However, it has also been shown that these volatile compounds vary according to geographical location, the botanical variety of coffee beans (robusta, arabica, among others) and mainly, according to the roasting process carried out (time, temperatures, between others) (5). Observing that coffee oil is one of the main carriers of the aroma and flavor of roasted coffee (1), which is obtained between 10-15% by weight (depending on the variety of the bean) of the organic residues of the brewed coffee, the so-called spent coffee grounds (SCG) (6).

Because of this, coffee oil is widely used as a flavoring in food industries (ice cream, beverages, instant coffee) (7) or as a natural ingredient in cosmetic and grooming products (8,9). As a “superior line” product with high quality, it must meet some specifications to be consumed and exported, one of those requirements being the determination of acidity, which also varies according to the soil of the crop, the climatic conditions, the management of the harvest, the species, etc. So, the raw material need to be first analyzed, to see if it is able to produce a final product with low acidity. The analysis of acidity and free fatty acids are extremely important parameters that allow us to know the state of deterioration of the product, during the storage of the raw material and, also the state of the oil after it has been extracted (10).

A novel coffee oil extraction procedure employing pressurized solvents

One of the most used techniques for the extraction of coffee oil is the one that uses organic solvents; the drawback is that this technique leaves permanent residues in the products that are considered toxic for human consumption (11). Therefore, modern and environmentally friendly technologies, such as the extraction of supercritical fluids (SFE), helps to give added value to the by-products of processes where different types of food participate (fruits, grains, coffee), being therefore widely used in the food industry (12).

But works using an extraction method based on Soxhlet principles are also reported, such as the work

by Phimsen et al., where they obtain a 13% yield when extracting from ground coffee an oil that is used as a biohydrotreated fuel, using hexane as a solvent (13). Topala et al., compared the composition of the coffee oil extracted

by Soxhlet and by SFE, using n-hexane and ethyl acetate as solvents, obtaining similar results in both processes. But in turn, better performance can be observed in less time when extracting with supercritical CO2 and n-hexane, but when using ethyl acetate as a solvent, it is possible to identify phenolic acids (14).

The methodology used in this work is described

by AOAC (15), using Soxhlet extraction with 200 mL of petroleum ether as solvent. PSE is an extraction procedure, which uses organic solvents at high pressure (70 - 140 bar) and temperature above the boiling point (50 - 200 ºC) (16).

Aiming to carry out the extraction of solid sample coffee oil quickly and with a lower solvent consumption, compared to traditional methods (17). In fact, this occur because the maximization in mass transfer rates and solubility can be reached, causing the breaking in solute-matrix interactions allowed by superficial equilibrium breaking, and promoting viscosity and solvent superficial tension reduction.

In this work a “home-made” PSE system (18), simple and of low cost, was applied for coffee oil extraction of the raw beans. The data obtained with PSE were compared to those obtained using the official AOAC (Soxhlet) extraction method.

Scientia Chromatographica 2019; 11(1):28-33 29

Pinto J. S. S., Nixdorf S. L., Sinisterra M. J., Lanรงas F. M.

2. Materials and methods

A novel coffee oil extraction procedure employing pressurized solvents

2.2. PSE System The PSE system (Figure 1), previously described in detail (18), consist of one pneumatic pump, wherein the

2.1. Reagents

solvent is placed and pressurized directly with nitrogen,

All reagents and solvents were analytical grade.

Petroleum ether was from Merck (Rio de Janeiro, Brazil).

Nitrogen was from AGA (Sรฃo Paulo, Brazil).

different sizes stainless steel extraction cells with filters; valves; oven and connections. The pressurized solvent percolates the sample disposed in the extraction cell, removing the analytes from the sample.

Figure 1. Representative drawing of the main components of the Pressurized Solvent Extraction (PSE) system. 1. Gas tank; 2. Solvent vessel; 3. Flow control valves; 4. Cell heater; 5. Extraction cell; 6. Collector

2.3. Sample preparation Fifty grams of raw arabica coffee beans were dried in stove at 100 ยบC for 5 hours. After cool, mill grinding and sieved in mesh 0.42 mm.

30

2.4. Soxhlet extraction The extraction of coffee oil is carried out from 8 grams of coffee previously prepared using the Soxhlet method (in triplicate), using 200 mL of petroleum ether for 8 hours at the heat plate (30 - 60 ยบC). Then solvent has been evaporated in a stove (105 ยบC) until residue has been dried, for approximately 1 hour. The coffee oil content was determined, after cooling, by gravimetric method.

Scientia Chromatographica 2019; 11(1):28-33

Pinto J. S. S., Nixdorf S. L., Sinisterra M. J., Lanรงas F. M.

A novel coffee oil extraction procedure employing pressurized solvents

2.5. PSE extraction The pressurization vessel is completed with petroleum ether and pressurized to 69 bars. Eight grams of coffee samples, in triplicate, previously described, were placed in cell extraction (30 cm x 0.8 cm. I.D.) and transferred to the heat system maintained at 80 ยบC. Initially the cell was filled out with petroleum ether and five minutes were necessary for thermal equilibrium. Static extraction was done for 10 minutes and dynamic extraction for more 10 min in a flow rate of 2 mL min-1 approximately. After finishing the extraction, the system was purged with nitrogen to eliminate all solvent remaining in cell. The solvent has been evaporated in rotary evaporator, being the remainder in the oil-extracted residue eliminated with nitrogen. The amount of oil was determined gravimetrically.

Table 1. Coffee oil extraction

Method

Solvent

Soxhlet

Petroleum ether

PSE

Petroleum ether

3. Results and discussion Table 1 describes the main data obtained for both investigated systems. It clearly shows the workability of PSE applied as an alternative for traditional methodology (Soxhlet) within 95% agreement. Comparisons also show a reduction in solvent consumption from 200 mL to 20 mL (a reduction of 10 times), as well as, in time analysis - from 480 to just 20 minutes (a reduction of over 20 times), to carry out the extraction. This reduction on time allows optimizing analytical parameters, making easier the laboratory methodology validation and the processes monitoring. Besides, the method variability as measured by the relative standard deviations of three consecutive extractions, shows a 3 times lower RSD for the PSE procedure. These reductions allow improving a coffee oil plant production by better controlling the process variables.

Solvent Volume (mL)

Extraction Time (min)

Yield (% w/w)

RSD (n=3)

16.23

0.40

20

20

15.97

0.15

200

4. Concluding remarks

480

process, characteristics that all together allow us to consider that PSE can be considered in this case as a green analytical chemistry method (GAC) for the coffee oil production.

The results presented in this work evidenced that the extraction conditions carried out in both methods had a significant effect on the yield of coffee oil. It was also found viable to work with the PSE system when compared to the Soxhlet system, since with the first one similar result are achieved in less time and using a lesser amount of solvent in a more inert atmosphere. These avoid the decomposition of thermally labile compounds during the Scientia Chromatographica 2019; 11(1):28-33 31

Pinto J. S. S., Nixdorf S. L., Sinisterra M. J., Lanças F. M.

Acknowledgements The authors are grateful to São Paulo Research Foundation, FAPESP (Grants 2017/02147-0, 2015/154625, and 2014/07347-9) and Conselho Nacional de Desenvolvimento Cientifico e Tecnológico, CNPq (Grant 307293/2014-9) for the financial support provided. This research project was financed in part by the Coordenação

32

A novel coffee oil extraction procedure employing pressurized solvents

de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001.

Conflict of interest statement The authors have declared no conflict of interest.

Scientia Chromatographica 2019; 11(1):28-33

Pinto J. S. S., Nixdorf S. L., Sinisterra M. J., Lanças F. M.

A novel coffee oil extraction procedure employing pressurized solvents

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[7] Raba DN, Poiana MA, Borozan AB, Stef M, Radu F, Popa MV. Investigation on crude and high-temperature heated coffee oil by ATRFTIR spectroscopy along with antioxidant and antimicrobial properties. PLoS One. 2015 Sep 14;10(9).

[8] Kobelnilk M, Fontanari GG, Cassimiro DL, Ribeiro CA, Crespi MS. Thermal behavior of coffee oil (Robusta and Arabica species). J Therm Anal Calorim. 2014 Mar 16;115(3):2045–52.

[9] Nosari ABFL, Lima JF, Serra OA, Freitas LAP. Improved green coffee oil antioxidant activity for cosmetical purpose by spray drying microencapsulation. Brazilian J Pharmacogn. 2015 May 1;25(3):307–11.

[10] Sajjadi B, Chen WY, Raman AAA, Ibrahim S. Microalgae lipid and biomass for biofuel production: A comprehensive review on lipid enhancement strategies and their effects on fatty acid composition. Vol. 97, Renewable and Sustainable Energy Reviews. Elsevier Ltd; 2018. p. 200–32.

[11] Khaw K-Y, Parat M-O, Shaw PN, Falconer JR. Solvent Supercritical Fluid Technologies to Extract Bioactive Compounds from Natural Sources: A Review. Molecules [Internet]. 2017 Jul 14 [cited 2020 Jun 8];22(7):1186. Available from: http://www.mdpi.com/14203049/22/7/1186 [12] Campos-Vega R, Loarca-Piña G, Vergara-Castañeda HA, Dave Oomah B. Spent coffee grounds: A review on current research and future prospects. Vol. 45, Trends in Food Science and Technology. Elsevier Ltd; 2015. p. 24–36.

[13] Phimsen S, Kiatkittipong W, Yamada H, Tagawa T, Kiatkittipong K, Laosiripojana N, et al. Oil extracted from spent coffee grounds for bio-hydrotreated diesel production. Energy Convers Manag. 2016 Oct 15;126:1028–36.

[14] Topala CM, Tataru LD. Infrared Spectra of Green Arabica Coffee Extraction using Supercritical Carbon Dioxide and Soxhlet Technique [Internet]. [cited 2020 Jun 8]. Available from: http://www.revistadechimie.ro [15] Torres-Moreno M, Torrescasana E, Salas-Salvadó J, Blanch C. Nutritional composition and fatty acids profile in cocoa beans and chocolates with different geographical origin and processing conditions. Food Chem. 2015 Jan 1;166:125–32.

[16] Efthymiopoulos I, Hellier P, Ladommatos N, Russo-Profili A, Eveleigh A, Aliev A, et al. Influence of solvent selection and extraction temperature on yield and composition of lipids extracted from spent coffee grounds. Ind Crops Prod. 2018 Sep 1;119:49–56.

[17] Armenta S, Garrigues S, de la Guardia M. The role of green extraction techniques in Green Analytical Chemistry. Vol. 71, TrAC Trends in Analytical Chemistry. Elsevier B.V.; 2015. p. 2–8.

[18] Pinto JSS, Lanças FM. Design, construction and evaluation of a simple pressurized solvent extraction system. J Braz Chem Soc. 2009;20(5):913–7.

Scientia Chromatographica 2019; 11(1):28-33 33

EVENTOS 2019

Colacro 2019

Website: https://www.colacro2019

O XVII Congresso Latino-Americano de Cromatografia e Técnicas Relacionadas (COLACRO XVII), ocorrerá de 14 a 19 de julho de 2019, na cidade de Aracaju, estado de Sergipe, nordeste brasileiro. Neste evento, a comunidade Latino-Americana de Cromatografia se reunirá, como faz tradicionalmente a cada dois anos. Pela primeira vez, em 34 anos de existência, o evento ocorrerá em uma cidade do nordeste brasileiro, reunindo estudantes, professores e pesquisadores da área cromatografia e de áreas relacionadas, de todos os cantos da América Latina, além de convidados e participantes de outros continentes, sob o agradável clima nordestino para celebrar o estado da arte da Cromatografia. Após o sucesso do XVI COLACRO em Lisboa/2016, a expectativa é que recebamos um grande número de participantes na região nordeste do país. ​

O COLACRO XVII será realizado nas dependências da Universidade Tiradentes em Aracaju, uma Universidade jovem com excelente infraestrutura que oferece um grande espaço moderno e multifuncional para a realização de todos os eventos programados além de uma área confortável para a exposição de equipamentos, que é uma forte característica deste evento.

O XVII Congresso Latino-Americano de Cromatografia (COLACRO XVII), nesta edição ocorrerá conjuntamente com o Simpósio Nacional de Cromatografia (SIMCRO 2019), e com o Workshop em Avanços Recentes no Preparo de Amostras (WARPA 2019).

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Scientia Chromatographica 2019; 11(1)

Eventos 2019

Iniciado em 2012, o WARPA tem como objetivo reunir docentes, pesquisadores, discentes e pós-graduandos das Unidades de Ensino Superior e da Iniciativa Privada de diferentes áreas da ciência para discussão dos recentes avanços de técnicas analíticas para o preparo de amostras. Dentre os temas abordados, destaca-se a miniaturização dos sistemas analíticos, hifenação de técnicas para automação das análises, minimização do volume de amostra, uso de fases extratoras seletivas e a utilização de tecnologias ambientalmente corretas, em direção ao cuidado preventivo do meio ambiente. ​ O COLACRO é o maior o evento de cromatografia e técnicas afins na América-Latina, tendo iniciado em 1986 no Rio de Janeiro (Brasil) pelo professor Fernando Lanças, e desde então tem ocorrido bienalmente nos países da América do Sul, e se consolidado como o mais importante meio para troca de informação e ideias na área de cromatografia e técnicas de separação. Em 2016, o COLACRO celebrou suas bodas de pérola (30 anos) e foi organizado, pela primeira vez fora do continente Americano, pelo grupo de Cromatografia da Sociedade Portuguesa de Química (SPQ), na encantadora Lisboa (Portugal), tendo como tema “Construindo Pontes de Cooperação em Ciência de Separação”. ​ “A Importância da Cromatografia no Desenvolvimento Tecnológico da América Latina” será o tema do XVII COLACRO, propondo uma reflexão sobre o desenvolvimento de metodologias cromatográficas associadas a novos equipamentos, e suas múltiplas aplicações em áreas de grande relevância social tais como saúde pública, meio ambiente, alimentos, combustíveis e muitas outras.

O COLACRO entende que para isso acontecer é fundamental a participação das empresas, associadas ao meio acadêmico, para o desenvolvimento da ciência e tecnologia, impulsionando, desta forma, o retorno ao crescimento científico e tecnológico, eixo fundamental do desenvolvimento econômico dos países da América Latina. ​ O programa incluirá conferências plenárias, simpósios satélites, comunicações orais e apresentações em poster, sendo a linha condutora os fundamentos, desenvolvimento e aplicações das técnicas cromatográficas e afins em áreas com importância reconhecida na sociedade, nomeadamente, ambiente, alimentar, forense, farmacêutica, aromas e fragrâncias, petroquímica, bioquímica entre muitas outras. Em paralelo teremos uma ampla feira/exposição de equipamentos de última geração e seminários técnicos a serem apresentados por pesquisadores indicados, associados a grandes empresas da área de Cromatografia e das Ciências de Separação em geral.

Está igualmente previsto um programa social muito atrativo oferecendo a oportunidade de conhecer as características da cultura do nordeste brasileiro associado ao interessante intercâmbio com cientistas renomados internacionalmente.

A Comissão Organizadora Local, formada por pesquisadores da UNIT, da UFRGS (Universidade Federal do Rio Grande do Sul) e da UFS (Universidade Federal de Sergipe) juntamente com o IIC (Instituto Internacional de Cromatografia) já iniciou os trabalhos com a indicação dos nomes dos palestrantes brasileiros e internacionais que deverão compor a programação deste grande evento. Muitos desses participantes, reunidos em maio de 2018 em Riva del Garda (Itália) durante o ISCC, participaram da indicação da cidade de Aracaju para a realização do evento e já confirmaram a sua participação. ​ Scientia Chromatographica 2019; 11(1):34-37 35

Eventos 2019

Apesar dos grandes desafios do momento atual, toda a Comissão Organizadora está muito entusiasmada, pelo local da realização do evento, que une o útil ao agradável. As instalações da UNIT são excelentes para a realização do Congresso e a cidade de Aracaju apresenta um agradável cenário nas maravilhosas praias do nordeste brasileiro. Aracaju é ainda pouco explorada pelo turismo, o que a torna particularmente interessante, pois alia a beleza natural às qualidades de uma capital moderna, limpa e segura. Aracaju é a menor capital brasileira, o que lhe confere ares de cidade do interior com as vantagens de capital. Tem um aeroporto pequeno, localizado e poucos quilômetros da orla, da UNIT e do centro da cidade, com voos diretos de Brasília, São Paulo e Rio de Janeiro, além de Salvador, Recife e Maceió e dois grandes shopping centers. A rede hoteleira é moderna e adequada a um evento do porte do COLACRO.

Aracaju é conhecida por ter a orla mais bonita do Brasil, com espaços agradáveis com restaurantes, feiras de artesanato, centro cultural de eventos, parques infantis e uma sede do projeto TAMAR, aberto à visitação diariamente.

As inscrições se iniciam em 01 de novembro de 2018 e as inscrições de trabalho irão até 15 de abril de 2019. Será um grande prazer receber toda a comunidade científico-tecnológica do Brasil e da América Latina em julho de 2019 em Aracaju!

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Eventos 2019

XIV Simpósio Latino-Americano de Química Analítica Ambiental, IX Encontro Nacional de Química Analítica (ENQA) e Workshop em Avanços Recentes no Preparo de Amostras (WARPA)

Data: 06 a 08 de novembro de 2019 Local: Dall’Onder Grande Hotel, Bento Gonçalves (RS) Organização: Universidade Federal do Rio Grande-FURG e Universidade Federal de Santa Maria (UFSM)

Apoio: Red para el Análisis de la Calidad Ambiental en América Latina (RACAL); International Association of Environmental Analytical Chemistry (IAEAC); Sociedade Brasileira de Química-Divisão de Química Ambiental (SBQ/DAMB).

Contacto: Prof. Ednei G. Primel http://laseac2019.furg.br laseac2019@furg.br

Scientia Chromatographica 2019; 11(1):34-37 37

Cursos 2019

IIC Calendário anual de atividades Visite www.iicweb.org

MÊS

DATA

DISCIPLINA

HORAS

Março

13 a 15

Cromatografia Líquida (HPLC ou CLAE)

24

Abril

10 a 12

Cromatografia Gasosa Moderna

24

Maio

15 a 17

Técnicas Modernas para Preparo de Amostras

24

Junho

25 a 28

Cromatografia Líquida Acoplada à Espectrometria de Massas

32

Julho

24 a 26

Cromatografia Líquida (HPLC ou CLAE)

24

Agosto

28 a 30

Cromatografia Líquida Avançada

24

Setembro

19 a 20

Como Desenvolver e Otimizar um Método em HPLC

16

Outubro

22 a 25

Cromatografia Líquida Acoplada à Espectrometria de Massas

32

Novembro

20 a 22

Cromatografia Gasosa Moderna

24

Dezembro

11 a 13

Cromatografia Líquida (HPLC ou CLAE)

24

Scientia Chromatographica 2019; 11(1) Instituto Internacional de Cromatografia ISSN 1984-4433

INSTITUTO INTERNACIONAL DE CROMATOGRAFIA

O Instituto Internacional de Cromatografia (IIC) possui como uma de suas principais missões o oferecimento de cursos de curta duração nas áreas de cromatografia e técnicas relacionadas.

Os objetivos dos cursos do IIC são o aprimoramento/formação/ atualização dos usuários das técnicas cromatográficas e afim (Preparo de Amostras, Espectrometria de Massas, Gestão da Qualidade, dentre outras), tanto do ponto de vista teórico quanto prático.

A filosofia educacional do IIC é: “ao invés de ensinar apenas como operar um equipamento específico (dar o peixe) o IIC ensina a técnica (como pescar)”.

Os cursos do Instituto Internacional de Cromatografia são coordenados pelos Diretores do IIC, e ministrados pelos coordenadores, auxiliados por uma equipe técnica e científica altamente qualificada, constituída de docentes pósgraduados nos melhores centros do país na área, e pós‑graduandos em fase de conclusão de suas teses. Na época em que cada curso for oferecido, uma relação dos instrutores é disponibilizada no website do IIC. O programa detalhado de cada curso pode ser obtido através de contacto com o IIC. Os cursos são ministrados com auxílio de recursos audiovisuais modernos (datashow‑computador; vídeos, demonstrações, resolução de problemas e outros recursos instrucionais). Os alunos recebem um livreto contendo cópia de todos os slides apresentados pelos instrutores, além de material bibliográfico de apoio. Em vários cursos também são fornecidos livros de autoria dos próprios docentes dos cursos. A maior parte dos cursos também tem aulas práticas de laboratório, conforme anunciado no folheto explicativo de cada curso.

Observações: • O I.I.C. oferece também cursos “in-house” (“in-company”). Interessados nesta modalidade devem contatar o IIC para obter mais detalhes.

• Com exceção dos cursos da área da qualidade (ISO, Validação e Auditoria) todos os demais possuem aulas teóricas e práticas de laboratório.

• O oferecimento efetivo de um curso depende de um número mínimo de inscritos no mesmo.

• O número de vagas dos cursos que envolvem laboratório está sendo limitado para melhor aproveitamento dos participantes.

• Visite o website www.iicweb.org para obter mais informações.

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Scientia Chromatographica 2019; 11(1) Instituto Internacional de Cromatografia ISSN 1984-4433

BIBLIOTECA IIC

O Bookstore divulgará o material de informação e formação produzido pelo IIC, incluindo Livros, filmes, slides, material didático de cursos e outras formas de divulgação dos materiais por ele ­produzido. Esses materiais podem ser adquiridos do IIC através do website www.iicweb.org/biblioteca.php

Cromatografia Líquida Moderna - Fernando M. Lanças Livro publicado pela Editora Átomo em maio de 2009, aborda de forma simples e didática os principais assuntos relacionados à Cromatografia Líquida Moderna (HPLC ou CLAE), desde a Teoria, Instrumentação, Colunas, Detectores, até aspectos da Validação, Preparo da Amostra e Análise Quantitativa.

O IIC recomenda este livro para todos os interessados em iniciar-se ou ­atualizar-se nesta técnica.

Cromatografia em Fase Gasosa - Fernando M. Lanças Livro de autoria do Prof. Lanças, abordando todos os princípios básicos: instrumentação, análise qualitativa e quantitativa, detectores e muitos outros aspectos da Cromatografia Gasosa.

Altamente recomendado para os iniciantes na técnica, os quais encontrarão explicações detalhadas e simples a respeito da maior parte dos fundamentos básicos da técnica.

Extração em Fase Sólida - Fernando M. Lanças De autoria do Prof. Lanças, este livro apresenta e discute as várias formas de extração em fase sólida (SPE), desde a mais clássica empregando cartuchos até as mais atuais como discos, placas, ponteiras, e outras. Também discute os princípios da micro extração em fase sólida (SPME) e da extração por sorção em barras de agitação (SBSE).

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Scientia Chromatographica 2019; 11(1)

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NORMAS PARA PUBLICAÇÃO

Normas para publicação de artigos no Scientia Chromatographica (a versão detalhada está disponível em nosso portal www.scientiachromatographica.com).

Escopo

Scientia Chromatographica publica trabalhos em todas as áreas da Cromatografia, incluindo GC (colunas capilares, empacotadas, preparativas), LC (convencional, HPLC, U-HPLC, Prep-LC, micro-LC, nano-LC, TLC, PC), SFC (colunas empacotadas ou capilares), Técnicas Acopladas (GC-MS, LC-MS, SFC-MS, LC-GC, SFE-CE, GCxGC, LCxLC) e Técnicas de Preparo de Amostras (SPME, SBSE, MEPS, QuEChERS, LLE, MAE,SPE, LLE, etc.). A partir de 2012 o Scientia publica os seguintes formatos de artigos: • Artigos Originais de Pesquisa • Comunicação (“Short Communication”) • Artigos de Revisão Crítica Os artigos de Revisão Crítica deverão antes de sua submissão serem discutidos com um dos ­co-editores mais relacionados ao assunto em questão. Devem conter uma contribuição nova a respeito de um assunto de grande interesse atual, incluindo uma discussão a respeito das vantagens e desvantagens do mesmo. O Scientia não publica apenas relato de artigos descritos na literatura, sem uma discussão crítica sobre os mesmos.

Os artigos Originiais de Pesquisa deverão conter resultados de laboratório e/ou teóricos, que signifiquem uma contribuição expressiva para a área de técnicas de separação, seja ela conceitual, na instrumentação, ou na aplicação.

Os artigos do tipo Comunicação deverão ter a mesma qualidade dos artigos Originais, porém devido a seu caráter de comunicação preliminar usualmente são de menor extensão.

Envio do Artigo

Os artigos deverão ser encaminhados para periodico@scientiachromatographica.org. Os artigos do tipo Revisão deverão antes de seu envio pelo website ter o aval de um dos co-Editores do periódico, caso contrário não serão avaliados.

Todos os artigos, independentemente do formato, deverão ser submetidos exclusivamente ao Scientia, com o entendimento de que eles não foram anteriormente submetidos, não estão sendo e não serão posteriormente publicados em outro veículo.

Autores que utilizarem tabelas, ilustrações, figuras, ou textos contendo mais de 25 palavras, anteriormente publicados em outro periódico – sendo ou não autores do artigo – deverão obter a devida permissão por escrito do portador dos direitos de cópia (“Copyright ”). Esse documento deverá permanecer de posse dos autores, sendo encaminhado ao Scientia, quando solicitado.

Idioma

Os artigos, com exeção dos de Revisão, podem ser escritos preferencialmente em inglês, porém em Português e Espanhol também serão aceitos. Os autores cujo idioma nativo não for o empregado na redação do artigo são orientados a solicitar a colaboração de colegas fluentes no idioma, antes de enviar o artigo para o periódico.

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Scientia Chromatographica 2019; 11(1):41-42 Instituto Internacional de Cromatografia ISSN 1984-4433

NORMAS PARA PUBLICAÇÃO

Tipos de contribuições aceitas para publicação no Scientia O Scientia Chromatographica considera para publicação quatro tipos de contribuição:

Artigos Originais de pesquisa: descrevem resultados de estudos completos. Deverão conter resultados de laboratório e/ou teóricos, que signifiquem uma contribuição expressiva para a área de técnicas de separação, seja ela conceitual, na instrumentação, ou na aplicação. Este tipo de contribuição é limitado a 6.000 palavras, incluindo as legendas das figuras e as referências, e no máximo 5 tabelas e/ou figuras somados. No momento do envio da prova de impressão, caso isto ocorra o autor será consultado se prefere revisar o artigo para enquadrá-lo em até 7 páginas, ou se prefere pagar as páginas excedentes. O número de páginas de um artigo depende muito das figuras e tabelas do mesmo. Este critério não é aplicado aos artigos convidados, cujo número de páginas será informado ao autor no momento do convite.

Comunicações (“Short Communication”): são artigos completos, porém que relatam resultados mais curtos, oportunos, e/ou cuja relevância requer sua rápida publicação. Deverão ter a mesma qualidade dos artigos Originais porém, devido a seu caráter de comunicação preliminar, usualmente são de menor extensão. Este tipo de publicação deve ter no máximo quatro páginas impressas, incluindo todo o artigo, ou seja, tabelas, figuras e referências. O autor deve indicar claramente que se trata de uma comunicação no topo da primeira página do artigo.

Artigos de Revisão crítica: revisões críticas sobre uma area específica das técnicas cromatográficas e relacionadas são também consideradas para publicação. Esses artigos devem se limitar a no máximo 10.000 palavras, incluindo as legendas, e até 10 tabelas e figuras somadas. Os artigos de Revisão Crítica deverão antes de sua submissão serem discutidos com um dos co-Editores mais relacionados ao assunto em questão. Artigos não encaminhados desta forma serão antes enviados a um co-Editor da área em que se enquadre para parecer e, somente então, serão enviados aos revisores, podendo atrasar significativamente sua publicação. Devem conter uma contribuição nova a respeito de um assunto de grande interesse atual, discutindo as vantagens e desvantagens do mesmo. O Scientia não publica apenas relato de artigos descritos na literatura, sem uma discussão crítica sobre os mesmos.

Artigos de Alta Prioridade: são publicados no primeiro número disponível do periódico, recebendo prioridade máxima de todo o sistema Editorial do periódico. Para justificar sua publicação como alta prioridade, os manuscritos deverão apresentar, de forma resumida, resultados importantes de recentes desenvolvimentos na área de cromatografia e técnicas relacionadas (espectrometria de massas, preparo de amostras, eletroforese capilar e outros). Não precisam conter resultados experimentais detalhados, sendo limitados a 2.500 palavras e três figuras e/ou tabelas combinadas.

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Scientia Chromatographica 2019; 11(1)

Publicação disponível na internet:

www.scientiachromatographica.com

2019

Volume 11 | Número 1 7

Capillary electrochromatography (CEC): recent materials for capillary column preparation, applications, and future perspectives Bruno Henrique Fumes, João Victor Basolli Borsatto Fernando Mauro Lanças

21 Fractionated Subcritical Carbon Dioxide Extraction of Triacyglycerides from Coffea arabica Jane Jesus da Silva Moreira, Jair Sebastião da Silva Pinto, Thais Camarotto Oliveira, Fernando Mauro Lanças

28 A novel coffee oil extraction procedure employing pressurized solvents Jair Sebastião da Silva Pinto, Suzana Lucy Nixdorf , Marcela Jordan-Sinisterra, Fernando Mauro Lanças

Instituto Internacional de Cromatografia IIC

Rua Princesa Isabel, 265 - Jardim Paraíso São Carlos (SP) - CEP 13561-140 Fone/ Fax: (16) 3501-4140 | www.iicweb.org