Method development for simultaneous determination of phthalate and eleven priority phenols as tert-butyldimethylsilyl derivatives in grab samples from wastewater treatment plants using GC-MS in Cape Town, South Africa

Abstract

Method was developed for the simultaneous determination of 17 classified and suspected endocrine-disrupting compounds (EDCs). Phenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 4-chlorophenol, 2,4-dimethylphenol, 2- methyl 4,6-dinitro-phenol, 2-chlorophenol, 2,4-dichlorophenol, 4-chloro-3-methylphenol, pentachlorophenol, dimethyl phthalate, diethyl phthalate, benzylbutyl phthalate, dioctyl phthalate, diethylhexylphthalate and dibutyl phthalate. Qualitative and quantitative analyses were performed by gas chromatography–mass spectrometry (GC–MS) using DB-5MS column. These compounds were evaluated using solid-phase extraction for raw and treated wastewater from a municipal treatment plant. Phenols were derivatized with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) to form their respective t-butyldimethylsilyl derivatives. The extraction recovery range from 73.21 to 101.32% for 2,4,6-TCP and DEHP respectively. The occurrence pattern of phenol is in the order of PCP > 2CP > POH > 2NP > 2M- 4,6 DNP (old plant) and PCP > 2M- 4,6 DNP > POH ≥ 2CP ≥ 2NP for old and new plants respectively. Phthalates ranked as DEP > DBP > DEHP with corresponding values of 2473 ± 991; 2000 ± 236; and 192 ± 127 µgL-1 in the new plant. The average percent removal of analytes range from 54.77 to 89.34% in the two plants investigated.