Simultaneous Detection Of 43 Emerging Contaminants In Tap Water By HPLC-MS/MS

Objectives:1.To establish a simultaneous detection method for 43 emerging contaminants(ECs)in tap water by liquid chromatography-triple quadrupole-tandem mass spectrometry(HPLC-QQQ-MS/MS).2.To explore the existence of emerging contaminants in tap water by analyzing the tap water samples collected from 43 sampling points.3.In order to continuously monitor the temporaldynamic changes of emerging contaminants in tap water,the Zhongdu Campus of Shanxi Medical Universitywas selected as a long-term monitoring point for sample collection and analysis for five months.Methods:1.Establishment of a method for screening ECs in tap water by HPLC-QQQ-MS/MSThe water samples were pretreated,enriched and concentrated by solid phase extraction..The collected eluent wasredissolved for HPLC-QQQ-MS/MS analyzing.Based on the idea of multiple target screening,the information database of precursor ions,product ions and retention times of 43 ECs were established by using standard substances.The raw data wasextracted by Mass Hunterqualitative analysis software for chromatographic peak analysis,and then quantified by standard curve method.2.Detection of ECs in tap water samplesThere were 31 provinces,municipalities and autonomous regions including Shanxi Province,Anhui Province,Gansu Province,Sichuan Province,Tianjin City,Beijing City,Heilongjiang Province,Jiangxi Province,Guangdong Province,Henan Province,Hunan Province,Chongqing City,Qinghai Province,Liaoning Province,Shandong Province,Hebei Province,Guizhou Province,Shaanxi Province,Zhejiang Province,Yunnan Province,Inner Mongolia Autonomous Region,Hainan Province,Guangxi Zhuang Autonomous Region,Jilin Province,Hubei Province,Jiangsu Province,Shanghai,Xinjiang Uygur Autonomous Region,Tibet Autonomous Region,Ningxia Province and Fujian Province.A total of 43 tap water samples(Z 1-Z 43)were collected.The HPLC-QQQ-MS/MS method established in this studywas used for pretreatment and instrumental analysis of tap water samples,and the detected ECs results were statistically analyzed.3.Long-term monitoringof tap water samples in Zhongdu Campus of Shanxi Medical UniversityThe Zhongdu Campus of Shanxi Medical University in Yuci District,Jinzhong City,Shanxi Province was selected as a long-term monitoring site.Tap water samples were collected regularly.A total of 49 samples(YC 1 ～ YC 49)were collected.After pretreatment and computer detection,the results of ECs were statistically analyzed.4.Risk assessmentThe human health risk assessment of emerging contaminantsdetected in tap water samples was carried out,and the maximum concentration detected in all samples was selected to simulate the risk of human exposure in the worst case.Results:1.Determination of ECs in tap water by HPLC-QQQ-MS/MS.In this study,solid phase extraction was used for sample pretreatment,and liquid chromatography-triple quadrupole-tandem mass spectrometry was used as the detection method.Based on the idea of targeted detection of emerging contaminants,a rapid detection and analysis method for 43 emerging contaminants in tap water was established.In this method,43 emerging contaminants had a good linear relationship in the linear range,and the average linear correlation coefficients(r)was 0.9954.The detection limit was 0.01 ng / L-0.60 ng / L,the limit of quantitation was 0.1 ng / L-10 ng / L,the intra-day precision was 0.05 %-14.8 %,the inter-day precision was 0.1 %-14.4 %,and the recovery was40.8 %-119.8 %.2.The detection,data analysis and human health risk assessment of ECs in tap water samples.A total of 18 emerging contaminants(ECs)were detected in tap water samples from 43 sites,including 6 drugs(33 %),5 pesticides(28 %),2 industrial pollutants(11 %),4transformation products(22 %)and 1 food additive(6 %).There were six emerging contaminants with a detection rate higher than 50 %,including two drugs(carbamazepine and diazepam),one pesticide(atrazine),one food additive(caffeine),and two conversion products(cotinine and deethylatrazine).The detected concentration range was ND-548.89 ng / L.The substance with the highest detection rate was atrazine,reaching86 %.The average concentrations of 1,2,3-benzotriazole,atrazine,carbendazim,deethylatrazine and desisopropylatrazine were 65.69 ng / L,48.35 ng / L,22.97 ng / L,22.41 ng / L and 23.32 ng / L,respectively.Among the five tap water samples(Z 13,Z 14,Z 20,Z 22 and Z 35)with the highest cumulative concentrations of emerging contaminants,the main pollutants were 1,2,3-benzotriazole,atrazine,deethylatrazine and desisopropylatrazine.A total of 7 emerging contaminants were detected and quantitatively analyzed in the long-term fixed-point monitoring of tap water in Zhongdu Campus of Yuci District,Jinzhong City,including 1 drug(diazepam),2 pesticides(carbofuran and atrazine),3transformation products(cotinine,deethylatrazine and desisopropylatrazine)and 1 food additive(caffeine).It was found that the types of emerging contaminants in local tap water were stable during the monitoring period,and the corresponding detected concentrations were also stable.The average concentrations and detection rates were :diazepam(0.54 ng / L,96 %),carbofuran(7.27 ng / L,100 %),atrazine(36.21 ng / L,100 %),cotinine(7.32 ng / L,100 %),deethylatrazine(13.65 ng / L,100 %),deisopropylatrazine(5.99 ng / L,100 %)and caffeine(1.91 ng / L,100 %).By estimating the risk entropy of different life stages of human,including 0 ～ 3 months,3 ～ 6 months,6 ～ 12 months,1 ～ 2 years,2 ～ 3 years,3 ～ 6 years,6 ～ 11 years,11 ～ 16 years,16 ～ 18 years and adults.The risk entropy in 0～12 months is slightly higher than that of other age groups for detected pharmcieuticals.The RQs of most ECs were less than0.01 indicating that there was no risk to human health.Only the RQs of atrazine at 0 ～ 12 month stage was between 0.01 and 0.1,indicating that infants at this stage might be under low-risk environment for atrazine exposure.Conclusions:In this study,a rapid detection and analysis method for 43 emerging contaminants in tap water by HPLC-QQQ-MS was established.The method is simple,sensitive and selective,and could meet the detection needs of trace pollutants in tap water.This study found the presence of emerging contaminants in actual tap water samples,and for the detected tap water samples,1,2,3-benzotriazole,atrazine,carbendazim,deethylatrazine and deisopropylatrazine were at a high pollution level,with an average concentration range of 22.41 ng/L to 65.69 ng / L.Through the long-term monitoring of the tap water in the laboratory of Zhongdu Campus of Shanxi Medical University,it was found that there were stable ECs present in the samples.Through the human health risk assessment of the detected emerging contaminants,it was found that atrazine had low exposure risk to infants aged 0-12 months.In addition,the other ECs did not have health risks.This study is helpful to understand the pollution of emerging contaminants in tap water and the health risks that may be caused to human to a certain extent,and to provide corresponding reference data for the management policies of related chemicals in the future.