Determination of estrogens in river water by gas chromatography-negative-ion chemical-ionization mass spectrometry.
A method for the determination of estrogens (17alpha-estradiol, 17beta-estradiol, estrone, ethynyl estradiol, and estriol) as pentafluorobenzyl-trimethylsilyl (PFB-TMS) derivatives by gas chromatography-mass spectrometry (GC-MS) with negative-ion chemical-ionization (NICI) is described. The NICI of all the derivatives produced an intense [M-PFB]- ion as the base peak. The reagent gas (methane) flow-rate and the ion source temperature were determined to be 2.0 ml/min and 240 degrees C, respectively, for the optimized NICI-selected ion monitoring (SIM) conditions. The sensitivities of the PFB-TMS derivatives in the NICI mode were 8.0-130 times higher than those of the PFB-TMS derivatives in electron ionization (EI) mode, and 12-25 times higher than those of all the TMS derivatives in the EI mode. This method was applied to the analysis of estrogens in river water using a solid-phase extraction as the sample preparation. The recoveries of the target chemicals from a river-water sample spiked with standards at 2 ng/l level were 85.8-126.5% (RSD, 6.2-13.0%). The methodical detection limits ranged from 0.10 to 0.28 ng/l.
Nakamura
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S
Yokogawa Analytical Systems Inc., Musashino-shi, Tokyo, Japan. sadao_nakamura@agilent.com
Sian
T H
TH
Daishima
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S
D004967:Estrogens / Q000032:analysis*; D005618:Fresh Water; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012015:Reference Standards; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004967:Estrogens; D014874:Water Pollutants, Chemical