Trace analysis of estrogenic chemicals in sewage effluent using liquid chromatography combined with tandem mass spectrometry.
A rapid, selective, sensitive, and reproducible method for the analysis of environmental estrogens, either natural or synthetic, present in samples from sewage treatment works (STW) has been developed. Isolation of these compounds from STWs was performed by applying a simple extraction procedure using an ENVI-CARB cartridge (a graphitized non porous carbon black) as the solid-phase extraction (SPE) system. Liquid chromatography coupled with atmospheric pressure chemical ionization (APCI) and tandem mass spectrometry was used for detection. For the multiple reaction monitoring (MRM) mode, the [M + H](+) ion of estrone and the [M + H-H(2)O](+) ions of 17beta-estradiol, estriol and 17alpha-ethynylestradiol were selected as the precursors for collisionally induced dissociation (CID). The average recoveries from sewage final effluent samples ranged from 84 to 93% for low levels, and from 89 to 95% for high levels. The precision of the method ranged from 11 to 8% for low level and from 9 to 7% for high level samples. The lower level of quantitation for these estrogens in STW samples was determined at 0.5 ng/L for 17beta-estradiol and 17alpha-ethynylestradiol, and 1 ng/L for estrone and estriol, based on 1-L aliquots of sewage treatment works water, using the optimum tuning parameters for each individual selected precursor ion/product ion transition. Compared to a previous gas chromatography/mass spectrometry (GC/MS) method for the analysis of ten STW samples, this method was shown to provide higher sensitivity and lower time consumption.