Simultaneous analysis of 45 pharmaceuticals and personal care products in sludge by matrix solid-phase dispersion and liquid chromatography tandem mass spectrometry

Pharmaceuticals and personal care products (PPCPs) are a class of emerging contaminants widely distributed in the wastewater treatment system. The simultaneous analysis of multiple PPCPs in the sludge, which is a complex matrix, is still not fully studied. In this study, a procedure based on matrix solid-phase dispersion (MSPD) for the extraction of PPCPs from the sludge with determination by liquid chromatography tandem mass spectrometry (LC-MS/MS) was investigated. Forty-five PPCPs, including antibiotics, nonsteroidal anti-inflammatory drugs, beta-blockers, antidepressants, antimicrobial agents, preservatives, UV filters, and so on, were studied. MSPD parameters, including the sorbent materials, the ratio of sample to sorbent, the eluent composition, and the elution volumes, were sequentially optimized. Best results were achieved by 0.1 g of sludge homogenized with 0.4 g of C18-bonded silica sorbent and elution by 6 mL methanol and 10 mL acetonitrile/5 % oxalic acid (8/2, v/v). The method quantification limits for the 45 PPCPs ranged 0.117-5.55 mu g/kg. The PPCP recoveries ranged from 50.3 to 107 % with relative standard deviation lower than 15 %. The proposed method was applied to analyze PPCPs in the sludge collected from a domestic wastewater treatment plant over 1 year. Thirteen PPCPs were detected, with the concentrations of ofloxacin and triclocarban more than 1000 mu g/kg. Temporal variations of the PPCP levels were observed. Thus, MSPD-LC-MS/MS method could achieve good sensitivity and recovery for the target PPCP analysis in the sludge samples, while MSPD provided one-step sample preparation which was easier and faster to perform compared to the commonly used methods.