在线固相萃取-液相色谱-三重四极杆质谱法同时测定饮用水中28种农药残留OA

Online solid-phase extraction-liquid chromatography-triple quadrupole mass spectrome-try was established to simultaneously determine 28 pesticide residues in drinking water.Three solid-phase extraction cartridges,namely,hydrophilic-lipophilic balance(HLB),C18,and weak anion exchange(WAX),were compared based on adsorption mechanisms,and HLB was identified as the best extraction cartridge.Extraction parameters were optimized via single-factor experiments,and the optimal conditions were determined as follows:water sample pH:5.0,sample loading volume:10 mL,sample loading flow rate:2 mL/min,and elution with 90%acetonitrile-2 mmol/L ammoni-um acetate-0.1%formic acid solution at a flow rate of 0.2 mL/min.The methodological validation re-sults showed that the 28 target compounds exhibited good linearity within the range of 0.025-10 μg/L(r≥0.997 9),with the limits of detection and quantification being 0.003-0.010 μg/L and 0.012-0.040 μg/L,respectively.Recoveries at three spiked levels ranged from 80.3%to 114%,with rela-tive standard deviations of 1.4%-14%.The method was applied to analyze 20 drinking water sam-ples.Acephate,bentazone,2,4-D,acetochlor,and chlorantraniliprole were detected at relative-ly high concentrations,whereas the other target analytes were observed at low concentrations.This sensitive and accurate method is suitable for the simultaneous analysis of 28 pesticide residues in drinking water.