Evaluation of extraction conditions and use of HPLC-MS for the simultaneous determination of acrylamide and its primary metabolite, N-acetyl-S-(2-carbamoylethyl)cysteine, in human urine

Extraction conditions were evaluated for the simultaneous determination of acrylamide and its primary metabolite, N-Acetyl-S-(2-carbamoylethyl)cysteine (NACEC), in human urine. Acrylamide is an animal carcinogen and a human neurotoxicant; and it is widely used within industry. The toxicity of acrylamide makes it a health concern, and the use of its metabolite, NACEC, as a biomarker of exposure would be of value in the prevention of occupational diseases. Sample preparation studies evaluating several different types of solid-phase extraction (SPE) cartridges and different buffered or acidic matrices of standing urine samples were conducted. Measurement of acrylamide and NACEC was by reversed-phase high performance liquid chromatography (HPLC) with a mobile phase gradient. Detection for quantification was by single ion monitoring using electrospray mass spectrometry (MS). A basic method validation, using the final optimized SPE conditions, was conducted. Recovery studies of fortified urine samples at various concentration levels demonstrated good accuracy and precision; recovery varied between 97 and 108% for acrylamide and with relative standard deviations (RSD) of 7.6% or less. Recovery for the NACEC metabolite varied between 97 and 102% with RSD of 10% or less. The limit of detection (LOD) for the optimized procedure was found to range from 0.02 to 0.03 mu g/mL for acrylamide and 0.1 to 0.2 mu g/ mL for NACEC in urine, using two chromatographic columns ot'different production lots.