Analysis of acrylamide in coffee by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is prone to interferences. According to our study, unknown background ions can entail an overestimation by up to 40% in case of coelution with acrylamide. In order to develop a precise and accurate quantification method for acrylamide, identification and removal of these interfering ions is requested. We thus studied potential isobaric impurities of acrylamide using liquid chromatography-high resolution mass spectrometry (LC-HRMS). An in-source fragment of N-Acetyl-β-alanine, a substance not yet reported in coffee, was identified as the main interfering ion. The characterization of the interference further triggered modification of the mobile phase-pH to alter the retention of N-Acetyl-β-alanine and achieve an interference free acrylamide determination. Two other compounds closely related to acrylamide namely 3-aminopropanamide and lactamide were also susceptible to in-source fragmentation, highlighting the pivotal role of chromatographic conditions to ensure a reliable quantification of acrylamide.
Keywords: Acrylamide; Coffee; Interference; LC-HRMS; LC-MS/MS; N-Acetyl-ß-alanine.
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