High-throughput Screening Of Emerging Pollutants In The Yellow River By High Resolution Mass Spectrometry

Objective:1.Based on high resolution mass spectrometry and suspect screening strategy,to establish a high-throughput screening approach of emerging pollutants(EPs)in surface water by liquid chromatography quadrupole time-of-flight mass spectrometry(HPLC-QTOF-MS).2.To high-throughput screen EPs in surface water in the Yellow River and reveal the occurrence and spatial distribution characteristics of a large number of EPs in the Yellow River.Methods:1.Establishment of high-throughput screening method of EPs in surface water by high resolution mass spectrometrySurface water samples were pretreated with HLB SPE columns for concentration and extraction,and the eluent was collected,dried by nitrogen gas and redissolved.Suspect screening strategy was adopted to establish a suspect compound database of EPs in surface water containing the accurate mass,chemical formula and other information.The surface water sample extracts were analyzed by HPLC-QTOF-MS with fullscan mode.The chromatographic and mass spectrometry peak(feature)information of precursor ion was extracted by Mass Hunter Profinder software and compared with information in the suspect compound database of 349 EPs and the compounds highly matched were selected.Then,MS/MS data acquisition of these compounds was carried out by target MS/MS mode and the obtained product ion spectral information was searched and compared with the open-source mass spectral databases(Mass Bank,Drug Bank,etc.)to obtain potential suspect EPs.Finally,features of these potential suspect EPs in samples were confirmed with the retention time,precursor ion and product ion of corresponding chemical standards,and finally quantified by calibration curve method.2.High-throughput screening of EPs in the Yellow River29 surface water samples were collected from various sites of the Yellow River.The sampling sites covered the upper,middle and lower streams of the Yellow River basin,including the main stream and tributaries,and the surrounding agricultural,industrial and residential areas.The samples were pretreated by SPE,analyzed by HPLC-QTOF-MS,screened by the established suspect database of 349 EPs in surface water and then confirmed and quantified by standards.The detection rate,concentration and distribution characteristics of EPs in the Yellow River were analyzed statistically.Results:1.Establishment of high-throughput screening method of EPs in surface water by high resolution mass spectrometryIn this study,an analytical method and chromatographic and mass spectrometry peak extraction method matched with HPLC-Q-TOF-MS high-throughput screening EPs in surface water were established.Finally,a suspect compound database of 349 EPs including names,chemical formula,accurate mass and CAS number was established,and66 EPs were confirmed by chemical standards and quantitated in real surface water samples.2.High-throughput screening and distribution characterization of EPs in the Yellow River80 EPs were identified in the surface water of Yellow River,including 29pharmaceuticals(36%),28 pesticides(35%),14 industrial products(17%),4 personal care products(5%),3 food additives(4%)and 2 transformation products(3%).Among them,the most frequent identified EPs was pharmaceuticals,and the concentration level of industrial products were high.There were 6 EPs with the highest detection rates of100%,which were hexa-methoxymethyl-melamine,phenazone,amantadine,6-propyl-2-thiouracil,desethylatrazine and atrazine.The detected EPs concentration ranged from ND to 774.73ng/L,and the high concentration EPs was2-benzothiazol-sulfonic acid(182.7ng/L),caffeine(186.84ng/L)and 2-naphthalene sulfonic acid(77.49ng/L).The detected pharmaceuticals mainly included antibiotics,nonsteroidal anti-inflammatory drugs and psychoactive medication,and among them antibiotics were the most detected(7 kinds).The pharmaceuticals with high detection rate were amantadine,phenazolone,6-propyl-2-thiouracil,diazepam,temazepam and daidzein,with detection rates above 90%.The pharmaceuticals with high average concentration were ofloxacin(76.91ng/L)、 4-Fluorobenzoylpropionic acid(75.68ng/L)and amantadine(54.2ng/L).The industrial pollutants mainly include flame retardants,metal preservative coating agents and so on.4 industrial pollutants with the highest detection rate were hexa-methoxymethyl-melamine,2-naphthalene sulfonic acid,2-benzothiazol-sulfonic acid and 1H-benzotriazole,and their detection rates were higher than 80%.4 industrial pollutants with high average concentration,including2-benzothiazol-sulfonic acid(182.7ng/L),2-naphthalene sulfonic acid(77.49ng/L),4-aminobenzamid(71.75ng/L)and 1H-benzotriazole(56.23ng/L).The pesticides detected mainly included insecticides,herbicides and fungicides,among which herbicides were the most detected(15 kinds).The pesticides with the highest detection rate were desethylatrazine,carbendazim,atrazine and 2-hydroxyatrazine,and the detection rates were all higher than 95%.The pesticides with the highest average concentration were desethylatrazine,carbendazim,atrazine and terbutryn.Among other usage EPs,the detection rate and concentration of phenylbenzimidazolium sulfonic acid,caffeine and cotinine were high.By cumulative summing up the concentrations of three types of EPs and the total cumulative EPs concentration to analyze their distribution characteristics,it was found that except one sample,the types of EPs with the highest cumulative concentration of the rest of the samples were industrial products or PPCPs.The highest EPs accumulative concentrations were detected at Y28(2276.99ng/L)、 Y22(2258.52ng/L)、Y16(2197.35ng/L)and Y6(1654.16ng/L).The cumulative concentration of pharmaceutical and personal care products(PPCPs)of Y22 was highest,and the PPCPs that contributed most were ofloxacin,amantadine,phenylbenzimidazolium sulfonic acid and hydrochlorothiazide.The site with the highest cumulative concentration of pesticides was Y16(790.87ng/L),and desethylatrazine contributed the most to the cumulative concentration of pesticides.The site with the highest cumulative concentration of industrial pollutants was Y22(967.44ng/L),and 1H-benzotriazole contributed the most to the cumulative concentration of industrial pollutants.Conclusions:1.This study established a high-throughput screening method for 349 EPs in surface water using high resolution mass spectrometry combined suspect screening strategy,and a suspect compound database of EPs in surface water were built.A technical tool is provided for the fast and effective screening of a large number of EPs in surface water without purchasing plenty of chemical standard substances.2.In this study,the surface water of the Yellow River was high-throughput screened with 349 EPs in the suspect database and 80 EPs were identified in the end.Screening of349 EPs could comprehensively represent the surface water pollution characteristics of the Yellow River region studied,which is conducive to a comprehensive understanding of the current situation of EPs pollution in the study area.14 EPs with high detection rate and high concentration in the Yellow River should be monitored,including 3 industrial products: 2-benzothiazol-sulfonic acid,2-naphthalene sulfonic acid and 1H-benzotriazole;4 pesticides: carbendazim,atrazine and its transformation products(desethylatrazine and2-hydroxyatrazine);6 pharmaceuticals: phenazolone,amantadine,temazepam,4-fluorbenzoyl propionic acid and 6-propyl-2-thiouracil;1 personal care products :phenylbenzimidazole sulfonic acid.Several detected EPs were rarely reported in previous studies,and this proved that high-throughput screening could greatly expand the recognition range of EPs in water bodies.The important value of high-throughput screening method to explore water pollution situation was demonstrated through the analysis of EPs distribution characteristics in the Yellow River.This study found that for Yellow River mainstream samples,the total cumulative concentration of EPs,industrial pollutants cumulative concentration and PPCPs cumulative concentration of were higher in the upstream than middle and lower streams,while there was no obvious difference in the cumulative concentration of pesticides.For the samples from tributaries,the total cumulative concentrations of EPs were generally higher than those in the main stream,as well as cumulative concentrations of PPCPs,industrial pollutants and pesticides.In the same tributary,the pollution in the lower reaches was higher than that in the upper reaches.Moreover,the type and concentration of EPs usually reflect the surrounding industry and sewage discharges.Sampling sites with high level of industrial pollutants are usually surrounded by industrial areas and industrial sewage outlets of enterprises,and the EPs with high pollution contribution are related to the types of enterprises.Municipal wastewater discharge often locates in the upstream of PPCPs sampling sites.The sampling sites with high pesticide contamination levels were all surrounded by agricultural industries,and different areas use different pesticides.By studying the pollution characteristics of EPs,we could find and the EPs that mainly contributes to the pollution.These areas are several branches of the Yellow River,including Erdaosha River,Kun River,Xihe River in Baotou city and Weihe River in Weinan City.