Gas chromatographic-mass spectrometric method for the determination of bisphenol A and its chlorinated derivatives in urban wastewater

摘要

The simultaneous determination of trace amounts of endocrine disruptors such as bisphenol A (BPA) and its monochloro, dichloro, trichloro and tetrachloro derivatives in wastewater has been developed using gas chromatography-mass spectrometry (GC-MS). Compounds were previously extracted from the aqueous samples using a liquid-liquid extraction procedure with a mixture of dichloromethane:carbon tetrachloride (25/75). After extraction, solvent was removed and a silylation step was carried out with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA). The silylated compounds were identified and quantified by GC-MS using an HP1-MS column. The retention times were 6.64 min for BPA silylated, 7.26 min for Cl-BPA silylated, 7.99 min for Cl_2-BPA silylated, 8.85 min for Cl_3-BPA silylated and 9.95 min for Cl_4-BPA silylated. A clean-up is not necessary using SIM mode. Deuterated anthracene (~2H_(10)-anthracene) was used as an internal standard. The detection limits obtained were 0.3, 0.6, 2.0, 4.5 and 13.0 ng L~(-1) for silylated BPA, Cl-BPA, Cl_2-BPA, Cl_3-BPA and Cl_4-BPA, respectively. The proposed method was applied satisfactory to the determination of these chemicals, in different types of wastewater previously spiked with different amounts of these chemicals at concentration levels ranging from 0.01 to 2.50μg L~(-1) for BPA, 0.05-2.50μg L~(-1) for Cl-BPA and 0.05-5.00 μg L~(-1) for Cl_2-BPA, Cl_3-BPA and Cl_4-BPA, respectively. The method was validated following standard addition methodology.