| Numerous compounds of environmental concern are substituted phenols. Chloro-, aryl- and alkyl-phenols and steroidal estrogens are among the ubiquitous environmental pollutants introduced by agricultural, medicinal, and industrial activities. A variety of phenols have been identified as priority pollutants in numerous countries, and some are suspected to be endocrine disruptors. Analysis of natural and synthetic estrogens is required for environmental purpose since estrogens from human sources are widespread in the environment and are believed to cause adverse effects in wildlife. The major challenge in the analysis of these phenolic compounds is to attain the high sensitivity required for the determination of these compounds at the trace levels present in many human and environmental samples. In this study, we developed three analytical methods utilizing liquid chromatography/electrospray tandem mass spectrometry (LC-ESI-MS/MS) to analyze three groups of phenolic compounds: (1) monehydroxyl metabolites of polycyclic aromatic hydrocarbons (PATE);(2) environmental phenols; and (3) steroidal estrogens. A major obstacle in the analysis of phenolic compounds by LC-MS and LC-MS/MS had been that many phenolic compounds are weakly ionizable in the electrospray ionization (ESI) and atmospheric pressure chemical ionization techniques of LC-MS and LC-MS/MS, leading to low inherent sensitivity. To address this problem, we evaluated several sulfonyl chlorides substituted with functional groups having high proton affinity as derivatization reagents to enhance the sensitivity for the analysis of phenolic compounds by LC-ESI-MS/NIS. The reagents investigated were dansyl chloride, 1,2-dimethylimidazole-4-sulfonyl (DMIS) chloride, pyridine-3-sulfonyl (PS) chloride, and 4-(1H pyrazol-1-yl)benzenesullonyl (PBS) chloride.;When the technique was applied to environmental phenolic compounds, the product ion spectra of the DMIS derivatives of hydoxyPAHs with three or more fused aromatic rings showed prominent ArO+ ions, the relative intensity of which increased with the number of rings. The DMIS derivatives of the selected phenolic compounds also showed excellent chromatographic properties. We developed and validated a novel analytical method employing enzyme hydrolysis, solid phase extraction, derivatization with DMIS chloride, and analysis by LC-ESI-MS/MS for the determination in human urine of 1-hydroxypyrene, a widely used biomarker for the assessment of human exposure to PAHs.;For analysis of the diphenolic compound, bisphenol A (BPA), PS chloride was found to be the reagent of choice. Upon collision-induced dissociation, PS derivatives of environmental phenols showed prominent analyte-specific fragment ions, ArO+, ArOH+, and [M+H-SO 2]2+. Using derivatization with PS chloride, a new analytical method based on LC-ESI-MS/MS for the determination of BPA and other environmental phenols in aquatic samples was developed.;The product ion spectra of the dansyl and DMIS derivatives of 17beta-estradiol (E2) were dominated by ions representing derivatization reagent moieties. In contrast, the product ion spectra of the PS and, to a lesser extent, the PBS derivatives of F2 showed analyte-specific fragment ions. Derivatization with PS chloride was therefore chosen for further investigation. The product ion spectrum of the PS derivative of E2 showed intense ions at m/z 272, assigned to the radical E2 cation, and at m/z 350, attributed to the loss of SO2 from the [M+H]+. Third-stage MS of the PS derivative of E2 with isolation and collisional activation of m/z 272 ion resulted in steroid C and D ring cleavages analogous to those observed in electron ionization mass spectrometry. The product ion spectra of the PS derivatives of other steroidal estrogens similarly showed estrogen-specific ions. Using derivatization with PS chloride, we developed an LC-ESI-MS/MS method with primary and confirmatory MS/MS transitions for the determination of E2 in serum. |
