Sediment and Tissue
Eurofins has the ability to perform a wide range of analyses on soil, sediment, surface water and tissue matrices. We’ve gained extensive experience in handling the unique situations presented by these types of samples. We can customize our processes to meet your reporting needs.
Why Choose Eurofins?
- In addition to our sediment and ecological expertise, we offer a full scope of testing services to meet all your project needs.
- We customize our processes to meet your reporting needs.
Compounds present in sediment may begin to affect benthic organisms at concentrations often lower than conventional analytical methods can quantify. Sediments frequently have a high moisture content (or low percent solids content), which ultimately affect the ability to achieve the low reporting limits required for ecological risk characterization. To remove the water portion from these samples, freeze-drying is a technique that is available. Although time consuming, water content can be reduced by greater than 50 percent.
Elutriate evaluation is commonly requested when river dredging is performed. This procedure helps consultants/scientists determine how much of the river bottom contamination is transported into the river water during dredging activities. Eurofins works closely with clients to design customized elutriate sampling plans.
Also in support of sediment-sampling programs, Eurofins is accustomed to using Acid Volatile Sulfides/Simultaneously Extracted Metals (AVS/ SEM). Typical metals requested are Cadmium, Copper, Lead, Mercury, Nickel and Zinc.
Additionally, grain size or particle size is run by hydrometer in accordance with ASTM D-422. We also offer Total Organic Carbon (TOC) Method SW-846 9060 or Standard Method 5310B modified (Lloyd Kahn) to meet your specific QAPP requirements.
Tissue Extraction and Analysis
Of particular interest are the levels of PCBs, PAHs and various metals in worms, fish and shellfish (edible portion).
In order to address the issue of pre-extraction preparation, Eurofins has elected to follow Great Lakes Environmental Assessment Section Procedure #31, “Fish Collection Procedure,” for the preparation of fish tissue. Of primary importance is that the submitter defines the portion of the sample for preparation (edible portion or entire animal). Adequate sample size is especially significant to achieve desired detection limits.
Several homogenization procedures are used to prepare the sample for extraction. These include grinding and blending with food-grade dry ice. The sample is then allowed to sublime for at least 12 hours or until the CO2 has vaporized (18 to 24 hours maximum). We keep the samples frozen during the preparation phase to maintain consistent sample integrity and to prevent layering of the sample. The sample is now ready for extraction of the analytes of interest.
Samples for determination of organics are processed by SW-846 methodology. Since the fat content of some organisms may interfere with organic analyses, Eurofins offers multiple cleanup techniques, including florisil, silica gel, sulfuric acid and gel permeation chromatography. These successfully remove the fats and excess organic components from the samples prior to injection on the instruments. Metals samples are prepared as noted previously. Various extraction techniques are available for sample preparation. Sonication and soxhlet are the most common. Soxhlet extraction for organic compounds allows the sample to reflux over time and thus remain in contact with the solvent longer. This procedure results in less particulate matter to filter and leads to more reproducible data than the sonication procedure. Sonication utilizes ultrasonic sound waves and the production of microbubbles when the waves impact the sample to release the organic compounds of interest into a liquid solvent environment. While either extraction method can be utilized, the sonication procedure will provide a quicker turnaround time for data generation. Clients should choose and communicate to the laboratory an extraction method prior to sample submittal.
To adapt the analyses to the organism of interest and therefore provide higher quality data, Eurofins employs a performance-based measurement system (PBMS) approach to method development. Therefore, the analysis is customized to optimize the extraction and analytical procedures.
Eurofins offers lipids analysis to provide clients with all the analytical data necessary to perform food-chain modeling. We use an automated approach utilizing Automated Solvent Extraction (ASE) by SW-846 3545 followed by a gravimetric determination to quantify the fat content. We’ve found this procedure to generate more accurate and reproducible results than the AOAC method, which uses an acid hydrolysis technique before the gravimetric fat determination.