LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY APPLIED TO THE ANALYSIS OF NATURAL AND SYNTHETIC STEROIDS IN ENVIRONMENTAL WATERS

A multiresidue analytical method for the determination of the most common and biologically active natural and synthetic steroids (four estrogens: estriol, 17?-estradiol, 17a-ethynylestradiol, estrone; one progestagen: progesterone and six androgens: trenbolone, boldenone, nandrolone, testosterone, 17a-methyltestosterone, stanozolol) in environmental waters was developed. The analytes were isolated from water samples by solid phase extraction (SPE) utilizing a graphitized carbon black adsorbent (Carbograph-1). The final samples were analyzed by reversed-phase high performance liquid chromatography with tandem mass spectrometry using atmospheric pressure chemical ionization (LC-APCI-MS-MS). Ionization was performed in a heated nebulizer (HN) interface operating in the positive ion mode. The protonated ions [M+H]+ and the dehydrated ions [M+H-H2O]+ (for estriol, 17a-estradiol, 17?-estradiol, and 17a-ethynylestradiol) were used as precursor ion for collision-induced dissociation (CID), and two diagnostic product ions for each analyte were identified for the unambiguous steroid confirmation by multiple reaction monitoring (MRM) mode. Method performance, for this analytical procedure, was validated by analyzing groundwater and river water samples fortified at level of 20 ng/L. The average recovery for each analyte exceeded 82%. Good method precision was demonstrated with percent relative standard deviation of less than 7.2% for all analytes.