Identification of indicator PPCPs in landfill leachates and livestock wastewaters using multi-residue analysis of 70 PPCPs: Analytical method development and application in Yangtze River Delta, China.

The source apportionment of pharmaceuticals and personal care products (PPCPs) in the water environment based on indicators (i-PPCPs) requires a comprehensive characterization of various emission sources using reliable analytical methods for a wide spectrum of PPCPs. In this study, a robust and sensitive method based on solid phase extraction (SPE) and ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) for analyzing 70 PPCPs belonging to 17 therapeutic classes in landfill leachates and livestock wastewaters was developed. The SPE cartridges, sample pH, elution solvents and chelating agent additions were optimized, and acceptable recoveries (60- 130% for 67 target compounds), low method quantification limits (landfill leachate: 3- 1309 ng/L; livestock wastewater: 3- 686 ng/L) and high precisions (repeatability: 0- 20% for over 99% injections; reproducibility: 0- 20% for over 90% injections) were obtained. Using the optimized analytical method to characterize PPCPs in the typical landfill leachate and livestock wastewater in Yangtze River Delta, China, we found anthelmintics, which were first reported in landfill leachates globally, exhibited the highest concentration (albendazole, maximum concentration of 61.6 μg/L), and therefore proposed albendazole as one of the promising i-PPCP candidates in landfill leachates. In livestock wastewaters, antibiotics lincomycin was the most abundant PPCP (maximum concentration: 735 μg/L) and identified as an i-PPCP candidate for livestock-originated contamination. In addition, 15 non-antibiotic PPCPs were first investigated in the livestock wastewater in China and some non-steroidal anti-inflammatory drugs, acetaminophen, diclofenac and naproxen, were detected at similar concentration level (1.16- 91.1 μg/L) to antibiotics, highlighting the necessity to include representative non-antibiotic PPCPs in the studies of emerging contaminants in livestock wastewaters. The developed method provides a tool to comprehensively investigate PPCPs in high-strength wastewater, and the preliminary findings in the characterization of typical landfill leachates and livestock wastewaters are helpful to select i-PPCPs for the source apportionment of PPCPs in Yangtze River Delta, China.