Method Improvement For The Determination Of Pharmacueticals And Personal Care Products In Water

Pharmaceuticals and personal care products(PPCPs) have received worldwide concerns as the emerging contaminants, due to their frequent detection in the aquatic environment. An accurate understanding about the occurrence and level of PPCPs in the environmentis the premise for the eluciation of their transport and transformation, as well as the assessment of their environmental risk. Because of so many categories of PPCPs and the difference of PPCPs production and usage, main PPCPs in aquatic environment in specific country/region are different. Therefore, it is necessary to develop targeted, accurate, sensitive and convenient analytical method. In this study, according to the characteristics of PPCPs production and consumption in China, an analytical methodfor 38 PPCPs was developed and demonstrated in a case study. Besides, a more precise analytical method was further developed by introducing more isotope internal standards, which is more accurate in quantification and robust.Firstly, a method for the determination of 38 common PPCPs(including 16 for human use and 22 for veterinary use) in Chinese water environment was developed, based on solid phase extraction(SPE) and liquid chromatography tandem mass spectrometry(LC-MS/MS), which is compatible with the meanstream method internationally. The material of sample bottle, SPE column, and the instrumental parameters of LC-MS/MS have been optimized. The equivalent substitution of domestic Cleanert PEP-2 for imported Oasis HLB greatly reduced the total cost. The method was applied in actual water samples, including drinking water, river waterand sewage, to investigate its applicability. As the results, the relative standard deviations of parallel experiments were less than 30%, and no concentration above the method quantitative limits was detected in blank control experiments. These results illustrate the good applibility of established method in the monitoring of various types of water.Secondly, a case study for two wastewater treatment facilities in the campus of Tsinghua University was conducted. The concentrations of PPCPs in both influent and effluent were determined along one semester. As the result, the established method can satisfy the purpose of this case study. The PPCPs concentrations in influent were found to be significantly correlated with the living and study activity of students. The removal efficienceies of both facilities were better than those of normal municipal sewage treatment plants, which should be due to the membrane bioreactor(MBR) process adopted and the fixed room temperature maintained all the year.Finally, a further improvement of the analytical method was investigated, using more isotpe internal standards(ISs). As current analytical methods only use very limited amount of internal standards, there are significant differences in both molecula structures and properties between target PPCPs and internal standards, which caused large system errors. According to the latest availability in the market, the amount of isotope labelled Iss used as cleanup spike were expaned from 4 to 31. Therfore most of the target compounds can be quantified by the isotope dilution methodology. The method detection limit(MDL) of the improved method is one order of magnitude lower than that of conventional internal standard method, and the precision and accuracy of the former are also better. This improved method provids a more accurate option for the monitoring the PPCPs in water, especially for the situationes of low concentration or complex matrix, as well as the academic researches requiring higher data accuracy.