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Background As one of the speculated bisphenols to replace bisphenol A (BPA), bisphenol F (BPF), naturally present in mustard, is structurally similar to BPA and may have similar estrogenic activity, but information on its toxicity is very limited compared to BPA. Objective In order to support the toxicology study of BPF at Heath Canada, a GC–MS method based on solid-phase extraction (SPE) and derivatization was developed for analysis of BPF in liver samples. Methods Samples were treated with β-glucuronidase to convert BPF glucuronide to free BPF for analysis of total BPF. Results The method was validated for free BPF at different spiking levels, and recoveries ranged from 90–97.5% with RSDs from 0.11–5.54%. The method was also validated for glucuronide-conjugated BPF at different spiking levels of BPF mono-β-D-glucuronide: recoveries ranged from 72.3–93.3% with RSDs from 1.7–8.94%. The method was used to analyze 60 liver tissue samples from rats dosed with BPF at different levels in a toxicology study. Free and glucuronide-conjugated BPF were not detected in any of the control samples, which were not dosed with BPF (average method detection limit: 0.31 ng/g) but detected in all the other liver tissue samples with levels increasing at higher doses. The percentage of glucuronide-conjugated BPF in total BPF varied among the liver samples, from as low as 9.8% to as high as 77.9%, indicating the importance of analyzing biological samples for BPF in both free and conjugated forms for total exposure. Conclusion A GC–MS method based on solid-phase extraction (SPE) and derivatization was developed for analysis of both free and glucuronide-conjugated BPF in liver samples. This method was validated not only for free BPF, but also for mono-β-D-glucuronide-conjugated BPF for the first time to confirm the efficiency of the deconjugation procedure with enzyme. Highlights This method can be adapted and applied for analysis of free and glucuronide-conjugated BPF in other biological samples with appropriate validation in target sample matrixes. [ABSTRACT FROM AUTHOR]

The article presents the discussion on Journal of AOAC INTERNATIONAL (the Journal) were released in 1915 under the name Journal of the Association of Official Agricultural Chemists including analytical sciences in both chemistry and microbiology.

The original solid-phase microextraction (SPME) fibers use an epoxy resin adhesive that releases bisphenol A (BPA) during thermal desorption of the fiber. This adversely affects the method detection limit and accuracy when these products are used for the determination of BPA. In this work, 5 new metal alloy SPME fibers that do not use epoxy resins were compared for the extraction of BPA in water. The performance of the optimum SPME fiber with 60 microm carbowax-polyethylene glycol coating for the headspace SPME of BPA in water was investigated systematically under different extraction conditions. Salt was found to increase the partitioning of BPA from water into the headspace until saturation was reached. Partitioning of BPA from water into the headspace also increased at higher extraction temperatures, as did longer extraction times. However, extraction of BPA from water onto the SPME fiber was not improved for solutions adjusted to pH 2 compared to the unadjusted neutral solutions. The new BPA method showed good linearity over the concentration range of 2.5 to 40 microg/L [correlation coefficient (r2) = 0.995] . The method detection limit for BPA was 0.5 microg/L, while the instrument detection limit was as low as 0.05 microg/L. Good repeatability was observed for BPA at levels of 5 and 20 microg/L with relative standard deviation values < 10%. The automated headspace SPME method developed in this work was used to investigate migration of BPA from polycarbonate bottles into water, and levels of BPA in water ranged from 1.7 to 4.1 microg/L.