Quantitative determination of Bisphenol A from human saliva using bulk derivatization and trap‐and‐elute liquid chromatography coupled to electrospray ionization mass spectrometry

Abstract

Endocrine disruptors cause adverse health effects as a result of their ability to shift the hormonal balance that is essential to the body. Bisphenol A (BPA) is an endocrine disruptor that has garnered much attention because of its presence in many consumer materials, which generates a significant risk for exposure. A method is presented for rapid detection of oral exposure to BPA directly from human saliva. Saliva was chosen because it serves as a noninvasive sampling route to detect BPA exposure; however, it is one of many complex biological matrices that have traditionally posed problems in quantitative analysis. Such analyses usually require extensive sample preparation to reduce interferences contributed by the sample matrix. Three validated methods are presented here that feature a streamlined sample-preparation strategy (bulk derivatization) prior to accurate and sensitive analysis by trap-and-elute liquid chromatography coupled to electrospray ionization mass spectrometry. Validated methods include standard addition calibration with variable injection volumes and multiple injection loading, as well as with incorporation of an internal standard. Reported limits of detection reached as low as 49.0 pg/ml (2.9 pg loaded on-column; equivalent to parts per trillion in saliva) among the presented methods with good accuracy and precision throughout. A proof-of-concept study is demonstrated to show that the final validated method has potential application to specific studies for trace-level BPA detection from real samples.

Derivatization of bisphenol A and its analogues with pyridine‐3‐sulfonyl chloride: multivariate optimization and fragmentation patterns by liquid chromatography/Orbitrap mass spectrometry

“…One potential problem when derivatizing compounds with two derivatizable groups is that the reaction might lead to mixtures of mono‐ and di‐substituted derivatives. For instance, derivatization of BPA with dansyl chloride has been reported to yield an important amount of mono‐dansylated BPA when the derivatization reaction is carried out under non optimized conditions 22. After derivatization with PS chloride, we examined the chromatograms for the mono‐derivatized bisphenols (Supplementary Table S1, Supporting Information), which were also present, but to a much lower extent than the di‐derivatized forms (data not shown).…”

Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

“…This system permits on-line sample preparation by trapping the analytes and then directly eluting them onto an analytical column for separation [29,30]. A RAM system has been used for quantitative determination of dansylated bisphenol A in human saliva [31]. Bulk derivatization, where the derivatization reagent was applied directly to the unprocessed biofluid, was implemented.…”

Restricted access media as a streamlined approach toward on‐line sample preparation: Recent advancements and applications

“…Another recent work featuring the use of MC-ODS columns was the trace detection of bisphenol-A (BPA) from human saliva [102]. Here, a novel approach toward trace detection was presented where the concept of bulk derivatization was used in conjunction with RAM trap technology to enable parts per trillion detection limits.…”

“…The pairing of these two characteristics allows SEC selection using the semipermeable methoxycellulose coating along with the pores of the porous silica gel particles to effectively exclude unwanted matrix interferences [80,90]. This MC-ODS trap has been heavily used in method development and is the focus of a number of application studies [30,[91][92][93][94][95][96][97][98][99][100][101][102].…”