Author
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Shappell, Nancy |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 6/5/2007 Publication Date: 9/16/2007 Citation: Shappell, N.W. 2007. Coupling LC MS-MS analysis of estrogens with E-Screen bioassay in the evaluation of agricultural wastewater. Meeting Abstract. 121st AOAC Annual Meeting & Exposition, Sept. 16-20, 2007, Anaheim, CA. Interpretive Summary: Technical Abstract: Solid phase extracted agricultural wastewater samples were evaluated by E-Screen and LC-MSMS. Detection limits for natural estrogens by LC-MSMS were ~1 pg/ul on column (original sample 2 ng/ l) while the E-Screen limits were 0.3 fg/ul E2 equivalents (E2Eq) on cells (original sample [20 pg/l]). The threshold for estrogenic activity in fish is 1-10 ng/l, depending on literature and compound - ethinyl estradiol vs estradiol, which is close to LC-MSMS detection limits. E-Screen is 100 times more sensitive and serves as a cumulative index of estrogenic activity. Matrix effects can present issues for both methods through signal quenching and cellular toxicity. Comparing swine wastewater samples from a lagoon constructed-wetland system yielded a R2 value of 0.82 between E2Eq from E-Screen and LC-MSMS concentrations of 17 beta-E2, estriol, and estrone converted to E2Eq. Preliminary evaluation of estrogenic activity by E-Screen, followed by LC-MSMS confirmatory analysis is useful when estrogenic contaminants are known. |
