ICP-MS determination of trace elements in fish

In 1996, USEPA Region 10 began a study of contaminants in fish collected from the Columbia River Basin. The study included analysis of a suite of parameters including total recoverable metals. Part of this project entailed the investigation of several options for the digestion and analysis of fish tissue samples. This article provides a comparison of the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) determination of 17 elements in fish tissue with and without the addition of hydrochloric acid (HCl) in the digestion. Omitting the addition of HCl, a reagent required in EPA Method 200.3 (1) and the basis for the digestion procedure reduced the isobaric molecular interferences in a difficult, carbon-rich matrix. This allowed determination of 17 elements of interest simultaneously by ICP-MS, enhancing sample throughput without compromising sensitivity, data quality, or accuracy. Sample preparation protocols are included.