Silylation of Acrylamide for Analysis by Solid-Phase Microextraction/Gas Chromatography/Ion-Trap Mass Spectrometry

Abstract

A method for quantitative analysis of acrylamide has been developed for use with headspace solid-phase microextraction (SPME). In the method, acrylamide undergoes silylation with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) to form the volatile N,O-bis(trimethylsilyl)acrylamide (BTMSA). Once formed, BTMSA is readily extracted from the headspace over the silylation reaction using a 100 μm poly(dimethylsiloxane) SPME fiber. A series of experiments was undertaken to optimize the amount of BSTFA, the silylation reaction temperature, the silylation reaction duration, and SPME sampling duration to maximize the analytical sensitivity for BTMSA. Acrylamide levels were quantified relative to a [¹³C₃]-acrylamide internal standard using gas chromatography/ion-trap mass spectrometry (GC/MS) in the single ion monitoring mode. An analytical working curve was constructed and found to be linear over the 4 to 6700 ppb acrylamide range investigated with a limit of detection of 0.9 ppb. The native acrylamide levels of three commercial cereals were measured using the optimized analytical method. Quantitative standard additions of acrylamide to the cereal matrixes demonstrated complete recovery of the spiked acrylamide. Keywords: Acrylamide; BSTFA; carcinogen; cereals; derivatization; GC/MS; silylation; SPME