Sources of overestimation in the analysis of acrylamide-in coffee by liquid chromatography mass spectrometry

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-beta-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-beta-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. (C) 2019 Elsevier B.V. All rights reserved.