Lab Matters Winter 2019 - Page 15

FROM THE BENCH Five Years to an EPA-Approved Cyanide Method: How Maine Achieved Success By Jim Eaton, PhD, Chemist II, Maine Health and Environmental Testing Laboratory In early 2004, Maine’s Health and Environmental Testing Laboratory (HETL) joined the US Centers for Disease Control and Prevention’s (CDC’s) Laboratory Response Network for Chemical Threats (LRN-C), and cyanide in blood was the first method that Maine scientists brought up. They trained at CDC’s National Center for Environmental Health (NCEH) laboratory in Atlanta. After returning home, HETL scientists speculated they should be able to analyze cyanide in drinking water by the same method, which would make analysis much easier, quicker and more environmentally friendly than the distillation method then in use. HETL tried several tests with good recovery and reasonable results for spiked samples and then initiated the validation process for a new drinking water method. After internet research, HETL scientists determined they needed to submit a proposal to the US Environmental Protection Agency (US EPA) for the method. In June 2005, HETL submitted the initial validation plan to the US EPA Region 1 laboratory in Boston. The plan was referred to the US EPA Office of Ground Water and Drinking Water in Cincinnati (EPA Cincinnati). In March 2007, EPA Cincinnati provided a validation plan to meet the US EPA request of a three-laboratory study completed on several different types of samples. At this point, membership in the LRN-C proved invaluable because LRN-C laboratories were running blood cyanide and thus had the expertise and equipment to quickly participate in a multi-lab validation of the proposed drinking water method. HETL scientists asked their counterparts in Michigan and Vermont to participate, and they accepted. Personal contacts with state and federal scientists developed at biannual LRN-C meetings likely contributed to members’ willingness to participate in the study. PublicHealthLabs @APHL During the validation study, laboratories in Maine, Vermont and Michigan analyzed seven replicates at two spiking levels in deionized water. During the validation study, laboratories in Maine, Vermont and Michigan analyzed seven replicates at two spiking levels in deionized water. Samples were spiked at 50 parts per billion (ppb) and at the US EPA Maximum Contaminant Level (MCL) for cyanide of 200 parts per billion (ppb). To assess interferences, US EPA recommended samples of high ionic strength and high total organic carbon (TOC). HETL used a salt mixture for the ionic strength samples and took high TOC samples that were submitted to its laboratory for routine testing. HETL then aliquoted these and sent them to Michigan and Vermont. HETL compiled the data from the three laboratories and, in January 2008, sent it to EPA Cincinnati for review. After making several minor method modifications, HETL was notified by EPA that the method had been accepted in June 2008. In August 2009, the method was published in the Federal Register APHL.org under US EPA drinking water method number ME355.01, meaning that the method was accepted as valid for any laboratory running this type of analysis. The five-year journey from initial concept to final acceptance and publication was completed at last. Success with US EPA could not have been achieved without the support of CDC NCEH and the willing participation of LRN-C member laboratories. HETL thanks all who assisted in this long journey, as it was truly a team effort. n DIGITAL EXTRA: Would your laboratory like to conduct a multi-laboratory validation study of one of its methods for submission to EPA? Contact Jennifer Liebreich at jennifer.liebreich@aphl.org Winter 2019 LAB MATTERS 13