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Vol. 5 Issue 2


Spring 2009

Interest in carcinogenic PAHs increasing By Becky Bilek, Ph.D, Technical Director Polycyclic Aromatic Hydrocarbons (PAHs) make up a subset of compounds that contain only carbon and hydrogen with the shared characteristic that the carbon atoms are arranged in multiple fused rings. More than 100 compounds are classified as PAHs, many of which are formed during the incomplete combustion of carbon-containing materials, including petroleum, coal, tobacco, food and other organic materials. Emission sources for these compounds include industrial plants, refineries, naturally occurring fires and automobile exhaust. Because these compounds are not very volatile and dissolve more easily in organic materials than in water, PAHs in the environment are generally more likely to be found in soil, sediment and oily substances than in water or air. PAHs are a human health concern as many individual PAH compounds have been classified as probable or possible carcinogens by entities such as the National Toxicology Program, the Environmental Protection Agency (EPA) and the International Agency for Research on Cancer. Recently the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH) selected 26 compounds that are classified as carcinogenic PAHs. Monitoring these carcinogenic PAHs, also known as cPAHs, will provide data to calculate a potency equivalency factor (PEF) to evaluate toxicity and assess risk. The compound Benzo(a)pyrene (BaP) has been studied extensively and serves as a reference compound. The measured concentrations of the list of 26 compounds, excluding quinoline, will be used to calculate a BaP equivalent value. A table listing PAH and cPAH compounds is published on page 3. Recently the Braun Intertec Analytical Laboratory added 18 compounds to the analysis of PAHs in order to be able to quantify all 36 PAH compounds (the noncarcinogenic PAHs and the MPCA list of 26 cPAHS). This analytical method uses gas chromatography-

Potential sources of PAHs

Emission sources for PAHs include industrial plants and naturally occurring fires. PAHs may be formed by the incomplete combustion of a number of carbon-containing materials, including food and tobacco.

mass spectrometry (GC-MS) in the selected ion monitoring (SIM) mode. SIM collects data on specific ions produced by each compound during the analysis and obtains lower detection limits by eliminating extra information. If you have questions about projects that require analysis for cPAHs, please contact the Braun Intertec Analytical Laboratory at 952.995.2600.

See PAH table on page 3 for more information

Lab Manager’s Corner: Braun Interport The Braun Intertec Analytical Laboratory was recently acknowledged as being one of the top five laboratories providing “customer satisfaction” as part of the American Council of Independent Laboratories Seal of Excellence program. As you can imagine, we are excited about this recognition, and we continue to develop ways to better serve you, such as our client portal called Braun Interport™ and our new summer hours. Braun Interport™ is a new feature that the laboratory is offering in 2009. This secure Web portal allows clients to access and view their report documents on-line as they are prepared. Braun Interport™ provides cost-effective, convenient options for how you work, communicate and receive documents from us. If you are interested in learning more about how Braun Interport™ might work for you, please contact your project manager.

We also strive to provide you with thorough and timely data, which is why in the summer we extend our hours to include Saturday receiving from 8 a.m. until noon. Summer hours will begin May 2 and continue through Oct. 31, excluding holiday weekends. We are available during our “off” hours, too, for sample receiving, should you need to drop off your samples at a different time. If you need special accommodations for your samples, please contact your project manager, who will work to meet your timeline requirements. Our next issue will include a quality assurance article that describes the relationship between reporting limits, method detection limits, reporting limit verification and J-flagged data. We will also feature new analyses that we will be able to provide this year. We wish you a wonderful spring and summer. - Tom Wagner

Soil Preparation by Microwave Extraction separately throughout the extraction process.

By Becky Bilek, Ph.D, Technical Director Last year the Environmental Protection Agency (EPA) issued Method 3546, which allows labs to use a microwave oven to extract organic compounds from soil, clay, sludge, sediments and solid wastes. The Braun Intertec Analytical Laboratory now uses a microwave system for the extraction of solid samples, instead of the accelerated solvent extraction (ASE) method used previously. While principles of the two methods are similar, the overall processes are different. Both the ASE and microwave methods expose soil samples submerged in organic solvents (such as methylene chloride or hexane) to heat and pressure. This causes the organic compounds to be extracted into the solvent. After separating the soil from the solvent, the solvent is analyzed using gas chromatography. Both methods also require the soil samples to be weighed out and placed into individual vessels. With ASE, solvent is added to each sample by the sample prep apparatus. The solvent is collected in a vial after the extraction is complete. While this process is automated for ease of use, the possibility of cross-contamination between adjacent samples exists because the solvent extract flows through common tubing inside the instrument. However, with the microwave system, soil and solvent are added manually to each vessel and contained


Comparison data regarding both methods was generated by the Braun Intertec Analytical Laboratory and indicates that extraction by microwave is at least as efficient as ASE, and may be slightly more aggressive. One of the most significant differences between the methods is total preparation time. The ASE unit heats and pressurizes each sample individually, and the extraction takes about 15 minutes to perform. Thus, a batch of 15 samples, as well as the required quality control samples, takes about five hours, not including additional preparation time. The microwave system, in contrast, allows the samples in the batch to be processed simultaneously, meaning that the same batch of 15 samples only takes about an hour to extract. While the amount of work a lab analyst does remains the same for either method, microwave preparation results in increased sample throughput and more efficient sample preparation prior to instrumental analysis. If you have any questions about this new preparation method, please contact the Braun Intertec Analytical Laboratory at 952.995.2600.

Meet Steve McKelvey • Lab Analyst IV • If you have ever had a question about working with the gas chromatograph (GC), or the gas chromatography-mass spectrometer (GC-MS), Steve McKelvey is the person to ask. Steve has worked in the Braun Intertec Analytical Laboratory for 10 years, mainly performing analyses with the GC and the GC-MS. He has an additional seven years of experience in the environmental field and brings a wealth of expertise to the lab every day. “I really enjoy working with the instruments and getting them to perform at their optimal levels,” Steve said. “It’s always rewarding to be working with multiple instruments and coordinating the timing it takes to complete the analyses.” Steve has developed a method for analyzing a list of chemicals called carcinogenic Polycyclic Aromatic Hydrocarbons, often referred to as cPAHs. These days he serves as the organics lab supervisor, where water and soil samples are analyzed. “Supervision is a new role for me,” he said, adding that he remains very involved with both GC and GC-MS projects. Steve attended Moorhead High School before going to St. Cloud

State University where he earned a double major in chemistry and earth science. His first job out of college was working with explosives in the oil fields of North Dakota, which he described as challenging and dangerous. Today, when he is not working in the lab, Steve enjoys woodworking and recently crafted a crib for his baby granddaughter. “I was really pleased with it,” he said. “It turned out really nice.”

A guide to Polycyclic Aromatic Hydrocarbons Carcinogenic PAHs Benz[a]anthracene Benzo[b]fluoranthene Benzo[j]fluoranthene Benzo[k]fluoranthene Benzo[a]pyrene Chrysene Dibenz[a,j]acridine Dibenz[a,h]acridine Dibenz(a,h)anthracene 7H-Dibenzo[c,g]carbazole Dibenzo[a,e]pyrene Dibenzo[a,h]pyrene Dibenzo[a,i]pyrene

Noncarcinogenic PAHs

Dibenzo[a,l]pyrene 7,12 Dimethylbenzanthracene 1,6-Dinitropyrene 1,8-Dinitropyrene Indeno[1,2,3,-c,d]pyrene 3-Methylcholanthrene 5-Methylchrysene 5-Nitroacenaphthene 1-Nitropyrene 4-Nitropyrene 6-Nitrochrysene 2-Nitrofluorene Quinoline

Acenaphthene Acenaphthylene Anthracene Benzo(g,h,i)perylene Fluoranthene Fluorene 2-Methylnaphthalene Naphthalene Phenanthrene Pyrene


Questions, Requests and Comments Thomas Wagner, 952.995.2650 Steven Albrecht, 952.995.2622 Braun Intertec Corporation 11001 Hampshire Avenue S Minneapolis, MN 55438 This newsletter contains only general information. For specific applications, please consult your engineering or environmental consultants and legal counsel.

Š2009 Braun Intertec Corporation

Analytical Laboratory Summer Hours The Analytical Laboratory is open to receive samples on Saturdays from 8 a.m. until noon beginning May 2 and extending through Oct. 31, with the exception of Memorial Day, Independence Day and Labor Day weekends. Normal receiving hours are from 8 a.m. to 5 p.m. Monday through Friday, and summer Saturdays from 8 a.m. until noon. The lab can be reached at 952.995.2600. As always, if you have a special project requiring sample receipt during off hours, please contact your project manager and we’ll accommodate your needs. Braun Intertec Analytical Laboratory 11001 Hampshire Avenue S Minneapolis, MN 55438

Providing engineering and environmental solutions since 1957