N,N'-diethyl-m-toluamide (m-DET): analysis of an insect repellent in human urine and serum by high-performance liquid chromatography.

A procedure for monitoring m-DET in human urine and serum is described. m-DET is removed from the urine specimen by partitioning into diethyl ether, but solid-phase extraction is used to remove it from human serum. The urine and serum m-DET values are determined by HPLC with a UV detector. The limit of detection was 0.09 micrograms/mL in urine and 0.09 micrograms/g for serum. The percent of m-DET recovered from human urine spiked between 0.50 and 8.00 micrograms/mL was 90 +/- 5.4%. For human serum spiked between 0.25 and 10.00, the percent recovered was 96 +/- 5.9%. The pooled relative standard deviations (RSD) for spiked matrices were 0.06 for urine and 0.06 for serum.