Estrogenic hormone steroids in aquatic environments and analytical challenge

GEOC 66

Yuegang Zuo, yzuo@umassd.edu, Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, 285 Old Westport Rd, North Dartmouth, MA 02747, K. Zhang, Department of Chemistry and Biochemistry, University of Massachusetts - Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02747, Yuejuan Lin, Dept. of Chemistry, University of Massachusetts Dartmouth, North Dartmouth, 02747, and Yiwei Deng, Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, MI 48128.
Estrogenic chemicals, particularly the synthetic contraceptive steroid ethynylestrodiol (EE2) and natural estrone (E1) and estradiol (E2), have attracted a great deal of scientific and public attention during recent years due to their occurrence in surface waters and sewage treatment plant effluents and their potential adverse effects on the development and reproduction of fish, wildlife and even humans. Several studies reported on the formation of different derivatization products of EE2 with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) + trimethylchlorosilane (TMCS)silylating reagent. Thus suggested that derivatization with BSTFA + TMCS might not be suitable for the determination of EE2 by GC-MS under the previously reported conditions. In this study, a procedure for the simultaneous determination of both natural and synthetic estrogenic steroids (estrone and ethynylestrodiol) in water is described. Analytes were derivatized with BSTFA + 1%TMCS in pyridine solution and determined by GC-MS. The effects of solvent, temperature, and reaction time on the derivatization of EE2 were investigated in order to prevent the formation of undesired multiple derivatization products and conversion of trimethylsilyl (TMS) derivatives of EE2 formed to their respective E1 derivatives reported in previous studies. The identity and mechanism of formation of multiple derivatives have been discussed. A new silylation mixture (BSTFA :TMCS:pyridine = 49.5:05:50 (v/v/v)) was employed to overcome these pitfalls and generate a single product of di-TMS derivative of EE2. This developed method has been successfully applied to the monitoring of estrogen hormones in aquatic environments.
 

Geochemistry Poster Session
6:00 PM-8:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Geochemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007