ANALYSIS OF LOW LEVELS OF FREE AND CONJUGATED SNYTHETIC AND NATURAL ESTROGEN HORMONES IN WATER AND WASTEWATER

An accurate and reliable method is developed for the detection 17 natural and synthetic estrogens, 5 of which are also in the conjugated form. This method uses a 500 mg Varian C-18 solid phase extraction (SPE) cartridge, followed by derivatization with bis(trimethylsilyl)trifluoroacetamide containing 1% trimethylchlorosilane as the derivatizing agent to produce trimethylsilyl-derivatives. The derivatization step took 15 minutes at room temperature to produce reproducible derivatives. The samples are analyzed with a GC/MS. The detection limits for all compounds ranges from 0.03 μg L−1 to 7.6 μg L−1 using a sample size of 200 ml. When sample volume is adjusted to 3 L the most sensitive compound produces a reproducible GC/MS response at 30 pg L−1. Recoveries range from 71 – 101% of all hormones through the entire method with relative standard deviation (RSD) ranging from 0 – 14% (n=3).