Simultaneous Determination of 14 Organic Pollutants in Water by Direct Injection-Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry

There are many types of organic pollutants in water, which exert great threat to human health. Developing highly efficient and precise quantification method for their detections is very important. The acrylamide, bentazone, 2,4D, dimethoate, picric acid, benzidine, pentachlorophenol, carbofuran, carbaryl, atrazine, demeton, malathion, parathion and chlorpyrifos are 14 types of important organic pollutants, which are highly harmful to human body and thereby are included in importantqualitycontrol indicators of current standard regulations, such as Environmental Quality Standards for Surface Water (GB3838—2002), Standards for Drinking Water Quality (GB5749—2006) and Quality Standard for Ground Water (GB/T14848—2017) in China. According to the specified examination methods of these standards, they commonly need enrichment of large volume of water samples before the further analysis. However, there are many drawbacks for such pretreatment: 1) The process is lengthy. 2) It can exhaust large amounts of reagents. 3) Sometimes it can produce false positive results. 4) What is even worse is being harmful for the experimenter′s health. Liquid chromatographytandem mass spectrometry is a qualitative and quantitative analysis method with high sensitivity, good selectivity and fast analysis speed, which is becoming more and more popular for the determination of trace level of organic pollutants. The direct injection method based on liquid chromatographytandem mass spectrometry has been applied in some organic pollutants examinations. However, there are still no reports on simultaneous determination of these 14 organic pollutants using direct injection method. In this study, a method of direct injectionultra high performance liquid chromatographytandem mass spectrometry (UPLCMS/MS) was developed for simultaneously determination of these 14 organic pollutants. Additionally, the dynamic multiple reaction monitoring (DMRM) mode was applied in UPLCMS/MS, which could dynamically allocate the retention time window of each target compound, significantly adjust the loading cycle time of multiple compounds and improve the analysis efficiency. Specifically, the water samples were filtered through 022 μm of microfiltration membrane and gradient eluted with ammonium acetate and acetonitrile. The flow rate was 03 mL/min and the column temperature was 40 ℃. The samples were detected by DMRM mode using positive and negative electrospray ionization (ESI±), and the 14 isotope internal standards were used for quantification by internal standard method. The calibration curves of the organic pollutants showed good linearity with the correlation coefficients (R2) over 0999 0. The limit of detection was 001005 μg/L, and the limit of quantitative was 005010 μg/L. The average recoveries at three spiked levels were 779%114% in different environmental water samples, and the RSD ranged from 02% to 141% (n=6). This method is simple, rapid, and high sensitivity, which is suitable for detection of 14 organic pollutants in the surface, underground and drinking water.