Determination of bisphenols in beverages by mixed-mode solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry

摘要

Facing growing restrictions on the use of bisphenol A in food contact materials, several bisphenol analogues are coming in use as the main alternatives to replace this chemical in most of its applications. This work reports a simple and robust method based on mixed-mode solid-phase extraction and stable-isotope dilution liquid chromatography‒tandem mass spectrometry for the analysis of bisphenol A and its main analogues ‒ bisphenol S, 4,4'-sulfonylbis(2-methylphenol), bisphenol F, bisphenol E, bisphenol B, bisphenol Z, bisphenol AF, bisphenol AP, tetrabromobisphenol A and bisphenol P ‒ in alcoholic and non-alcoholic beverages. Mixed-mode solid-phase extraction, combining cationic exchange and reversed-phase mechanisms, was optimized to provide a selective extraction and purification of the target analytes. Derivatization of bisphenols with pyridine-3-sulfonyl chloride allowed increased their ionization efficiency by electrospray ionization. Validation of the proposed method was performed in terms of selectivity, matrix effects, linearity, precision, measurement uncertainty, trueness and limits of detection. Satisfactory repeatability and intermediate precision were obtained; the related relative standard deviations were ≤8.6 % and ≤12 %, respectively. The relative expanded uncertainty (k=2) was below 20 % for all bisphenol analogues and the trueness of the method was demonstrated by spike recovery experiments. Limits of detection ranged from 1.26 ng L-1 to 27.9 ng L-1 for all compounds. Eventually, several canned and non-canned popular beverages were analyzed to demonstrate the applicability of the method.