Quantitation of mercapturic acids from acrylamide and glycidamide in human urine using a column switching tool with two trap columns and electrospray tandem mass spectrometry.

A sensitive and specific electrospray tandem mass spectrometry method using a column switching unit with two trap columns was established to quantify the mercapturates (MAs) of acrylamide (AA) and glycidamide (GA) in human urine. A specially endcapped material was applied for trapping the hydrophilic MAs and a pre-trap column was used to remove lipophilic compounds from the directly injected urine to protect the trap column. The limits of quantitation for AA–MA and GA–MA in urine were 0.5μg/L and 1μg/L, respectively. Urine was spiked with deuterated internal standards and injected directly into LC–MS/MS. Urine of smokers (n=13) revealed the highest concentrations of AA–MA and GA–MA in the range of 61–706μg/L and 5–54μg/L, respectively. Lower levels for AA–MA (14–102μg/L) and GA–MA (1–11μg/L) were detected in non-smokers (n=13).