Optimization of an analytical method based on miniaturized matrix solid-phase dispersion combined with gas chromatography-mass spectrometry for the determination of bisphenols in mussel samples

Abstract

In this study, a new method has been optimized to determinate nine bisphenols (BPs) in mussel samples. This approach is based on miniaturized matrix solid-phase dispersion combined with gas chromatography-mass spectrometry determination after trimethylsilylation with 99% N,O-Bis-(trimethylsilyl)trifluoroacetamide + 1 % trimethylchlorosilane. The optimization process investigated the derivatization (derivatizing agent volume, time and temperature) and sample preparation (C18 co-column packed and C18 dispersant agent amounts and elution volume) parameters. A second clean-up step was performed using EMR-Lipid cartridges in order to efficiently remove lipids from mussel, the optimized parameters were Captiva EMR-Lipid sorbent amount and elution volume. The whole method was validated and very good linearity (r2 > 0.99) was obtained. The recoveries (accuracy) at two concentration levels ranged from 51.2 to 109 % and the coefficients of variation (precision) were between 0.55 and 13 %. The limits of quantification were between 0.014 μg/Kg dry weight for BPM and 4.0 μg/Kg dry weight for BPS. The analytical procedure was applied to four mussel samples from Galician Rías. Except for one of four samples whose BPAF level was below the limit of quantification, all BPs were found in concentrations that ranged from 0.39 to 301 μg/Kg dry weight.