A Comparison of the Accuracy of Measurement of Urine Thiocyanate by Spectrophotometry and Ion Chromatography in a Population Without Known Exposure to Cyanide

Résumé du livre

Background: Urine thiocyanate(UTC) has been used as a marker of cyanide exposure. In 1996, 65 of 75(87%) workers in a TN plant had elevated UTC. After this, the testing laboratory(NMS) changed their testing method from spectrophotometry(SP) to ion chromatography(IC). Subsequently, only 1 of 13(8%) workers had elevated UTC. This prompted further investigation. Methods: 55 subjects without exposure to cyanide were tested for UTC by SP and IC. Known amounts of thiocyanate were added to a sample, and the resulting specimens were tested. A survey of laboratories was conducted. Results: The mean UTC level(mg/ml) by IC was 3.24 (s = 3.75). The mean UTC level by SP was 16.84 (s = 9.78). The RMS error was 8.06 for IC. The RMS error was 60.31for SP. Three laboratories perform approximately 2400 UTC tests yearly in the US. Conclusions: The UTC testing by NMS in 1996 using the SP method overestimated levels.