The U.S. Environmental Protection Agency has developed draft guidance for the assessment and control of bioconcentratable contaminants in surface waters that are not covered by water quality criteria. The guidance document contains analytical procedures for identification and quantification of bioconcentratable contaminants in effluents, sediments, and tissues. These analytical procedures were the subject of a multilaboratory round-robin study in 1992. The results reported in this article are from five of the 12 laboratories that completed the round-robin study. Analyses of data from the five laboratories show that analytical variance explains the large observed intralaboratory variability in surrogate recoveries. Sample variance is minor relative to analytical and laboratory variances. All five laboratories isolated and positively identified only three of eight spiked compounds at >50% frequency using the proposed analytical procedures and gas chromatography-mass spectrometry library search method. The inability of the library search method to detect some of the reference spike chemicals is a concern because the methods are intended to detect unknown bioconcentratable chemicals. In general, the multistep procedure for each matrix was complex, prone to analyte loss, time intensive, and analytically demanding. Specific procedural problems and alternative methods are discussed, and recommendations for improvement are presented.
