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EDITORIAL Ochratoxin, produced mainly by the fungi Aspergillus ochraceus and Penicillium verrucosum, can be found in a wide variety of commodities such as raisins, barley, soy products, coffee, etc. Though the ochratoxin amounts may be relatively low, it is often not rapidly removed from the body and its levels may accumulate in the blood and other selected tissues of either humans or animals consuming contaminated food. Ochratoxin is primarily a kidney toxin but if the concentration is sufficiently high, there can be damage to the liver as well. Ochratoxin is a carcinogen in rats and mice and is suspected to be the causative agent of a human disease, Balkan Endemic Nephropathy, which affects the kidneys. Often, tumors are associated with this disease. Sonja Steininger

Romer Labs® CheckSample-Survey (CSS) – Ochratoxin A in wheat Introduction Romer Labs Diagnostic GmbH has launched the CheckSample-Survey (CSS) for Ochratoxin A (OTA) in wheat as part of its integral service. The objective of Romer Labs® CheckSample-Survey is to provide an interlaboratory comparison study of OTA analysis in wheat flour. The purpose of this study is to provide a platform for customers to assess effectiveness and accuracy of their test methods as part of their internal analytical quality management system. Preparation of the test material: The test material of this Check-Sample-Survey (M13401O) was prepared by Romer Labs Diagnostic GmbH, Austria. Natural contaminated wheat from a retail source was analysed for Ochratoxin A by reference methods and characterized. A milling and mixing procedure was used to thoroughly blend the material. The resulting test material was then dispensed into aluminium sample bags to create individual sub-samples (approx. 55 g) that were stored in appropriate conditions previous to distribution. · Romer Labs® Spotlights Vol. 27

Homogeneity Nine randomly selected test material samples were analyzed in duplicate. The available analytical data of the characterization (18 data point analyses with 9 extractions from the bulk sample - each extract run in duplicate) showed sufficient homogeneity of the test material and was not included into the calculation of the assigned value of the interlaboratory comparison. Initially statistical tests checked the data for any widely discrepant pairs using Cochran’s test. No such pairs were found and no data was removed. Thereafter the remaining data were subject to analysis of variance to estimate the sampling and analytical variances.

1 1   1  

Austria Brazil   Bulgaria   China   Croa8a   France   Greece   Hungary   Ireland   Japan   Korea   Poland   Serbia   Singapore   Slovenia   Spain   United  Arab  Emirates   United  Kingdom   USA  


13 13   2   1  

1 2  


1 1  

2 4  

5 2   1  


Figure 1. Participants by countries

Distribution The test material of this Check-Sample-Survey has been dispatched in October 2013 to 98 laboratories all over Austria, Brazil, Bulgaria, China, Croatia, France, Greece, Hungary, Ireland, Japan, Korea, Poland, Serbia, Singapore, Slovenia, Spain, the United Arab Emirates, the United Kingdom and the USA. Each participant received a wheat test material packed in an envelope together with instructions and a result form. Of these, 78 participants returned their results within the timescale demanded by this Check-Sample-Survey, which makes 80 % (see Figure 1). About 41 % of participants can be attributed to the Food and Feed sector, whereas 41 % are Research Institutes and Service Laboratories (see Figure 2). 30 participants used ELISA (Enzyme Linked Immunosorbent Assay) and 48 participants used HPLC (High Performance Liquid Chromatography), with different detection systems like MS (Mass Spectrometry), MSMS and FLD (Fluorescence Detector).


Food and  Feed  sector   41%   Research  Ins3tutes  and   Service  Laboratories   no  informa3on  provided  


Figure 2. Participants by industry

Results Participants were required to report their data in μg/kg before the closing date for this test, November 30th 2013. Results for Ochratoxin A (OTA) were submitted by 78 participants. A summary of the results of the Romer Labs® Check-Sample-Survey is shown in Table 1 and Figure 3 displays the satisfactory results [%] by employed method.


satisfactory results [%]

82% 80% 63% 60%






Figure 3. % satisfactory results by employed method · Romer Labs® Spotlights Vol. 27

Table 1 - Summary of Results Analyte

Assigned Value (µg/kg)

Number of satisfactory results

Number of questionable results

Total number of results

% satisfactory






73 %

Table 2 - Summary of statistical analysis of assigned value [µg/kg] data points [n] (after removing non valid data)

robust mean [X]

robust standard deviation [σ]

uncertainty [u]

robust RSD [%]






Calculation of Assigned Value X: The assigned value, X, i.e. the best estimation of the true concentration of OTA, was set as the consensus of the results submitted by participants. After removing non-valid data (results from participants not correcting for recovery and results which were labeled as ‘not corrected for recovery’), the assigned value was calculated as the robust mean by Huber’s H15 method. Detailed results of the statistical assessment are shown in Table 2.

Z-scores: The z-score relates the error in the result to the target standard deviation (σp) which is set ahead of the test and reflects ‘best practice’ or fitness for purpose. A histogram of the participant´s z-scores is displayed in Figure 4. A z-score between +2 and -2 is considered a satisfactory performance, between +2 and +3 or between -2 and -3 is considered a questionable performance, and anything outside this range (>+3 or <-3) is considered unsatisfactory (Visser, 2006).

Figure 4. Histogram of participant´s z-scores · Romer Labs® Spotlights Vol. 27



Education Address

Sonja Steininger, MSc Production Associate at Romer Labs Diagnostic GmbH since 2011 University of Applied Sciences Tulln, Biotechnology Master Thesis: “Development of a LC-MS-Method for the Detection of Pyrrolizidinalkaloids” Romer Labs Diagnostic GmbH, Technopark 1, 3430 Tulln, Austria

Tel: +43 2272 61533, Fax: +43 2272 61533-111



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Romer Labs UK Ltd. The Heath Business and Technical Park Runcorn, Cheshire WA7 4QX

Newsletter is published by Romer Labs Division Holding GmbH - Austria

Tel: +44 845 519 5010

Technopark 1, 3430 Tulln, Austria, Tel: +43 2272 61533


Fax: +43 2272 61533 13177, e-Mail: Editor: Hannes Binder. Publisher: Erich Erber · Romer Labs® Spotlights Vol. 27


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