June 2020 -The Experts at Environmental Standards examined the Challenges of Analyzing Hexavalent Chromium to the Tune of ng/L Measurements

The Experts at Environmental Standards examined the Challenges of Analyzing Hexavalent Chromium to the Tune of ng/L Measurements

Environmental Standards’ consulting chemistry professionals continue to make valuable contributions to the field of environmental chemistry. We are pleased to announce the manuscript, “The Challenges Associated with Generating Reliable Nanogram-per-liter Measurements of Hexavalent Chromium in Groundwater” has been accepted for publication by Environmental Toxicology and Chemistry.

The manuscript was written by Environmental Standards’ Allison Felix, Quality Assurance Chemist; Jennifer Gable, Principal Chemist; Rock J. Vitale, CEAC, Technical Director of Chemistry/Principal; David Gratson, CEAC, Senior Technical Chemist; and Dr. Neil Carriker (retired from Tennessee Valley Authority). The manuscript presents the results of two studies investigating the challenges of evaluating ng/L concentrations of hexavalent chromium [Cr(VI)] in groundwater.

The US EPA and several states are evaluating regulatory limits for Cr(VI) below 100 ng/L, increasing the importance of obtaining accurate and reliable data. In the study, chemically preserved and unpreserved aliquots of a groundwater sample were spiked with a known amount of Cr(VI), then analyzed in tandem with sets of preserved and unpreserved performance test samples over 28 days. The studies showed that while Cr(VI) appears to be relatively stable over 28 days, it may be sensitive to minor matrix changes after collection. Most significantly, the studies demonstrated significant challenges to measuring Cr(VI) below 100 ng/L, as the results can be subject to positive bias or contamination that may not be readily apparent. The authors concluded that Cr(VI) measurements using a US EPA‑published method below 100 ng/L may be categorized as semi-quantitative at best.

Environmental Toxicology and Chemistry is a monthly peer-reviewed scientific journal. It was established in 1982, and is published by Wiley-Blackwell in conjunction with the Society of Environmental Toxicology and Chemistry.

Environmental Standards, Inc. is an internationally recognized environmental consulting firm specializing in environmental chemistry/quality assurance, complex analytical project design and oversight (e.g., per- and polyfluoroalkyl substances [PFAS]), analytical data validation, environmental forensics/litigation support. Some of our consulting chemistry offerings include:

For additional information, contact Rock Vitale at  610.935.5577.

Rock J. Vitale

Technical Director of Chemistry