分散液相微萃取联合气相色谱质谱检测水中11种有机磷农药和阿特拉津方法的建立

目的 建立分散液相微萃取气相色谱质谱测定水样中11种有机磷农药和阿特拉津的方法。方法 分别对气相色谱条件、气相质谱条件进行优化，以提高萃取效率，优选条件建立方法后检测自来水和河水水样中有机磷农药。取10 mL水样，将200 μL二甲苯和800μL甲醇分别作为萃取剂和分散剂并混合后，注入水样中乳化分散，离心后取1 μL上层有机相进样分析。气相色谱采用HP5毛细管色谱柱（30 m×0.25 mm，0.25 μm）程序升温分离，质谱采用EI离子源，选择离子监测模式定量。结果 待测农药和阿特拉津在2.0~50 ng/mL范围内线性良好。方法检出限为0.12～1.38 ng/mL，测定精密度为5.57%～9.85%。将该方法应用于自来水和河水的测定，加标回收率为75.5%~107%。结论 方法简单快速，萃取和浓缩同时进行，轻质萃取剂在萃取后更易取出，适用于水样中有机磷农药的分析。

Detection of 11 Organophosphate Pesticides and Atrazine in Water by Dispersive Liquid-Liquid Microextraction

【Abstract】 Objective To develop a method for detecting 11 organophosphate pesticides and atrazine in water samples by dispersive liquidliquid microextraction combined with gas chromatographymass spectrometry (DLLMEGC/MS) . Methods DLLME and GCMS parameters were optimized for efficient extraction of chemicals. The proposed method was used for detecting organophosphate pesticides in tap water and river water samples, with 200 μL of dimethylbenzene as extractant and 800 μL of methanol as dispersant. They were mixed, emulsified and dispersed into 10 mL of water samples. The extractant (1 μL) from centrifugation was injected into the GC/MS system for analyses. GC separation was performed on HP5 column (30 m×0.25 mm, 0.25 μm) by temperature programming. Mass spectrometric analysis was done with EI and selected ion monitoring (SIM) mode was used for quantitative analysis. Results Good linear ranges for detecting the 11 pesticides and atrazine appeared from 2.0 ng/mL to 50 ng/mL, with a limit of 0.121.38 ng/mL. The relative standard derivations (RSDs) ranged from 5.57% to 9.85%. The average recoveries ranged from 75.5% to 107%. Conclusion The method is sensitive and rapid, with simultaneous extraction and concentration procedures. The lowdensity organic solvent after extraction is easy to isolate. The method fits for analyses of organophosphate pesticides and atrazine in water samples.