Abstract |
At two laboratories, an analytical method to determine polychlorinated biphenyls (PCBs) in serum was evaluated for its ability to recover in vitro-spiked PCBs from bovine and human serum. Statistically significant differences (p < 0.05) were found in the results obtained for the two matrices at both laboratories. Previously an interlaboratory bias between the laboratories of +3.3% had been established by using bovine serum; however, with human serum the average interlaboratory bias was -9.5% resulting in a change in absolute bias of approximately 13%. The analytes determined in the base materials before they were in vitro-spiked with PCBs were dichlorodiphenyldichloroethylene (p,p'-DDE), PCBs, and serum lipids (i.e., total cholesterol, triglycerides, free cholesterol and phospholipids). The concentration of analytes and lipids was higher in base human serum than in base bovine serum. (Copyright (c) 1992 by Marcel Dekker, Inc.) |