Emerging Contaminants (Jan 2020)
Occurrence of pharmaceutical and personal care products (PPCPs) in wastewater and receiving waters in South Africa using LC-Orbitrap™ MS
Abstract
There is continued interest in the occurrence and monitoring of emerging contaminants (ECs) in wastewater treatment plants (WWTPs) to assess their potential impact when released into the environment. The objective of this study was to determine the occurrence of pharmaceutical and personal care products (PPCPs) in WWTP influents and effluents and receiving river waters in Pretoria, South Africa. Targeted screening and identification of PPCPs in the samples was done using liquid chromatography (LC) coupled with high resolution mass spectrometry (HRMS) Orbitrap™ HRMS, after clean-up and preconcentration with Waters Oasis® hydrophilic-lipophilic-balanced (HLB) solid phase extraction (SPE) cartridges. Of the 156 target analytes screened in the study, 120 could be satisfactorily determined under the study conditions, with 71 and 73 compounds being detected and quantified in the influent and effluent samples, respectively. Concentrations in the influents ranged from < ILOQ-14.2 μg L−1 and those in the effluent from < ILOQ - 2.45 μg L−1. It was found that 84% of the quantified compounds belonged to various classes of pharmaceuticals. Ibuprofen, caffeine, paracetamol and estradiol were the major individual contaminants in influent samples with average concentrations of 14.2, 8.68, 4.79 and 1.02 μg L−1, respectively. In the effluent samples, the highest concentrations were recorded for estradiol (2.45 μg L−1), ibuprofen (1.03 μg L−1) and efavirenz (0.58 μg L−1). The highest mean concentrations (above 0.5 μg L−1) recorded in the river water samples were for ibuprofen, (4.14 μg L−1downstream; 3.19 μg L−1 upstream), caffeine (2.98 μg L−1 downstream; 1.42 μg L−1 upstream), paraxanthine (1.22 μg L−1 downstream; 0.798 μg L−1 upstream). Analysis of river water samples also revealed that PPCP contamination in the river system cannot be solely attributed to the WWTP effluents. Twenty-four compounds presented in this study are reported for the first time in South African surface waters.
