TestAmerica's New Methods and Capabilities

EPA Method 8260B SIM

Honolulu Laboratory

Method Application:

The method is used for a select group of analytes that drastically improves low level detection limits. The 82060B SIM method is ideal when running methanol preserved samples collected by incremental sampling methodology (ISM) for VOC analysis. The Honolulu laboratory can report Trichloroethylene (TCE) at 0.2ug/Kg.

Market Application:

The method is designed for those entities that perform incremental sub sampling for certain volatile chemicals of potential concern (COPC).

Hawaii's Department of Health (DOH) performed a characterization study with TestAmerica, on a U.S. Air Force base for subsurface contamination. The study focused on groundwater and soil gas data used in determining environmental risk hazards. In the investigation, core increment soil samples were extracted from contaminant locations and Single Ion Monitoring (SIM) analysis was applied, reducing the reported MDLs.

Advantages:

When performing an incremental sub sampling VOC process, field samples are preserved in methanol. This generally forces a dilution factor of 50, raising the reporting limits. The SIM approach allows the client to obtain reporting limits closer to the standard 8260 limits they expect, while performing the incremental sampling methodology.

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TPH Analysis GC Chromatogram Interpretation

Ask the Expert Question: 
Is there a way to distinguish whether TPH hits in a sample are from diesel, gasoline or mineral oil?

Expert Response:
The product causing the positive TPH results can generally be identified from the pattern of contamination present in the chromatogram provided the TPH was analyzed by method SW846 8015B or a similar Gas Chromatograph (GC) analysis.

Each of the petroleum products will show analytes in a generally well defined Carbon Number range (for example, gasoline is primarily from C4-C12, Diesel Fuel from C10 to C28, etc), and each of these products also have a very distinct distribution pattern within that carbon range. Identification is then based on both the carbon range and the actual distribution within that carbon range (there can be some overlap of the carbon number range for the various products). Our petroleum chemists are very experienced in evaluating these patterns and establishing the petroleum product present, and can evaluate the GC chromatograms from the analysis for identification.

It is also possible that the results are due to something other than petroleum products. The GC TPH methods are not necessarily specific for only petroleum products, but will include any compounds that elute within a defined Carbon Number range. Again, an evaluation of the chromatographs by a trained chemist can usually identify the cause of the positive results.

View Johnny Mitchell's expert profile

TestAmerica's New Methods and Capabilities

SW 8015B/ Iowa OA-2 Analyte Addition - Crude Oil
Cedar Falls Laboratory

Method Application:

This method is used to determine the total extractable hydrocarbons as Crude Oil present in a sample.

Market Application:

At the request of the Nebraska Department of Environmental Health, the laboratory validated this analyte using the IA-OA2 method. This request was made for the potential release of crude oil from a new oil pipeline being constructed in the state.

The Legislature recently introduced a bill that would require oil companies that own, operate, or manage a pipeline in Nebraska, to file an extensive application process with the state's Public Service Commission. This would require the submission of a pre-filed testimony, application framework, in addition to providing evidence of any environmental and economic studies of the proposed pipelines.

Advantages:

This method/analyte would use area of the entire chromatogram and compare it against a crude oil standard versus the traditional OA-2 comparing the chromatogram to individual regions of refined gasoline, diesel, and waste oil standards.

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Methane Analysis in Waters

Ask the Expert Question:

Water samples were collected from wells that were believed to be impacted by methane due to hydraulic fracturing and analyzed by two different laboratories. Two different analytical methods were run, RSK-175 and EPA Method 18. The results from the same sample source were about an order of magnitude different. Both methods used the analysis of headspace. Do you know why such a large difference would occur?

Experts Response:

In response to your question about large differences in results from two methods - RSK-175 and EPA method 18, I suspect that the differences relate to differing approaches in purging methane from each sample. RSK-175 is intended to measure dissolved gases, such as methane, in water samples, whereas EPA method 18 is designed for analyzing volatiles in air samples. The results for EPA 18 will depend on the how the laboratory created the headspace vapor sample, as that step is not defined in the method.

I suggest you evaluate how the methane in the water sample was converted to a gaseous sample, and also evaluate how standardization was performed for EPA 18. Another contributing factor is how the integrity of the water sample was maintained from collection to time of analysis. Unless the samples remained tightly sealed until analysis was performed, some methane could have been lost prior to analysis.

In summary, both methods should provide accurate methane analysis, so the main issues to investigate are the sample preservation and handling prior to analysis, and particularly how the EPA 18 headspace was created.

View Dr. Jack Tuschall's expert profile

Question on Incremental Sampling Methodologies

Ask the Expert Question:
One of the main tenants of the Incremental Sampling Methodologies approach is the analysis of a larger analytical subsample. For organic analysis, this doesn't seem to be a problem, but it is for metals. The digestion blocks that are the norm in environmental labs basically fix the analytical sample at 1 or maybe 2 grams. In fact, the official digestion methods are only validated for these small sample sizes. Is pulverization the only way to really get around the limitation on the analytical subsample size?

Experts Response:
You are correct that using large subsamples is a common part of Incremental Sampling Methodology (ISM). For organics using 10-30 g is already the norm so this isn't really a change for organic extractions. As you point out most metals digestion methods are optimized for 1-2 g aliquots. There are two common ways to address this limitation.

What do you know about the next wave of contaminants of emerging concern from the EPA?

TestAmerica is hosting its second webinar, Measurement of Pharmaceutical and Personal Care Products in Complex Matrices on April 14 at 1:30PM EST. Dave Herbert, Business Development Manager at TestAmerica will be presenting on the impact of Pharmaceuticals and Personal Care Products (PPCP’s) in our nations waterways.

Join us for the presentation and learn how TestAmerica's efforts in this emerging market go beyond the routine analysis of water by developing method capabilities to detect PPCPs in more complex matrices including waste water and sediments. Unlike typical water analyses, wastewater and sediments matrices contain high levels of organic materials and suspended solids, and require a more rigorous extraction process to identify and measure trace level PPCPs.

Click here to learn more about the presentation and register, space is limited.

Sampling Protocols for Collecting a Tap Water Sample for Lead Analysis

Ask the Expert Question:
What are the sampling protocols for collecting a tap water sample to analyze for lead?
Expert Response:
There are 2 guidelines for collecting a sample for the testing for lead.

According to EPA's lead and copper rule for drinking water, it is recommended that you collect a first-draw sample from a tap where the sample has stood in the pipes for at least 6 hours (e.g., no flushing, showering, etc.). First draw samples collected at single-family residences should be drawn from the cold-water kitchen tap or bathroom tap. Collect the sample into a 1-liter poly container. The laboratory can acidify the sample upon receipt for preservation.

For water quality monitoring, the sampling guideline indicates that the water source should be fully flushed for 10 minutes. Then collect the sample into a 500ml (or 250ml) poly bottle preserved with nitric acid.

View Cam Pham's expert profile