STL Introduces Unique Chromium Speciation Method

PRESS RELEASE

Date March 13, 2007
For Immediate Release

Severn Trent Laboratories, Inc. (STL) is one of the first commercial laboratories to offer the newly approved SW-846 Method 6800, which utilizes the Speciated Isotope Dilution Mass Spectrometry (SIDMS) technique. This technique provides improved data quality for Chromium Speciation by correcting for conversions between the trivalent and hexavalent chromium species, yielding more accurate results for hexavalent chromium.  

In the SIDMS technique, known amounts of enriched isotopes of the target element are added to the sample prior to analysis. The interconversion of valence species for the enriched isotopes is then measured, and a corresponding correction factor is applied to the measured concentrations of the target element. This unique approach ensures that valence interconversions that occur prior to analysis (and after enriched isotope spiking) are accounted for in the reported results. Traditional methods have historically attempted to preserve the valence state of each species prior to analysis, which proves difficult in a variety of matrices, sample collection, sample preparation and transport circumstances. In addition, Method 6800 can be expanded to include other total and speciated metals analysis such as mercury, tin, and selenium.

Method 6800 is a definitive analytical technique that provides better sensitivity, accuracy, and selectivity than other EPA SW-846 methods used for total and speciated chromium analysis. According to Stu Nagourney, Quality Assurance Officer for the New Jersey Department of Environmental Protection, “Method 6800 offers the potential to provide the most accurate and complete assay of Cr(VI) in matrices where redox conditions complicate results obtained by other determinative analytical methods.”

In addition to working closely with method developers and state agency representatives, STL’s Dr. Mark Bruce, Albert Vicinie, and William Reinheimer have held seminars and given presentations on the details of Method 6800. Their paper titled, "The Commercialization of Method 6800: Speciated Isotope Dilution Mass Spectrometry for the Determination of Hexavalent Chromium,” discusses the successful transition of the complex new method from an academic to a commercial setting. For a copy of the paper, or to ask Dr. Bruce and Mr. Vicinie a question, please go to STL’s Ask the Expert webpage.

About STL
Severn Trent Laboratories, Inc. (STL) is the industry's leading environmental testing company. Operations in the United States include 32 laboratories, 16 Service Centers and QED Environmental Systems, Inc., the leading supplier of groundwater sampling equipment and remediation pumping systems. STL affiliates include the Aerotech P&K team, which brings together the capabilities of Aerotech Laboratories, Inc. and P&K Microbiology Services, Inc. STL employs over 2,100 people and has revenues of $245 million in the United States.

For more information, contact:
Jim Miller
Vice President Business Development
Severn Trent Laboratories, Inc.
716-691-2600
Visit our website @ www.stl-inc.com