The application of standard methods for the determination of toxaphene in environmental media

In the United States, it is necessary to analyze for toxaphene using approved, validated methods acceptable to the regulatory agencies. As a result of an interlaboratory study and technical exchanges among the US EPA Region IV (EPA), the State of Georgia Environmental Protection Division (EPD), and Hercules Incorporated, guidelines for the application of SW-846 Method 8080 were developed. Results of analyses for sludge, soil, and water samples agreed within a percent relative standard deviation (% RSD) range of 6.9–20%. Through continued technical interchanges, guidance for the application of SW-846 Method 8081 has been developed. The results of analyses of fourteen split samples of soil and sediment produced a percent relative standard deviation that ranged from 1.6% to 127%, with an average of 38%. When two unusually divergent results were removed from consideration, the average % RSD reduced to 26%. The results of analyses of split samples show agreement between the EPA laboratory and a Hercules contract laboratory. Therefore, the guidance has achieved its purpose of producing agreement among data from different laboratories so that data reviewers may have assurance that the analytical method has been applied correctly and consistently for the determination of toxaphene in environmental samples.