原位衍生化-分散液液微萃取-气相色谱法测定环境水样中酚类物质的含量
Determination of phenols in water samples using simultaneous derivatization and dispersive liquid- liquid microextraction followed by gas chromatography
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摘要: 本研究建立了原位衍生化-分散液液微萃取-气相色谱测定水样中酚类化合物含量的方法,并考察了衍生化反应过程以及萃取过程的相关因素对实验结果的影响。实验结果表明最佳条件为:在5 m L分析水样中(p H=7.00),加入800μL衍生剂乙酸酐,置于50℃水浴中加热30 min,猝冷至室温后,以200μL二氯甲烷为萃取剂,以10μL甲醇为分散剂,密封后振荡后离心5 min,取1.00μL萃取液进行分析。本法线性范围为0.024.00μg/m L,相关系数R2≥0.9951,方法检出限为1.98μg/L。实际水样测定的相对标准偏差≤6.90%,回收率为59.6%119.2%。Abstract: A simple,rapid and sensitive derivatization and microextraction technique for the determination of Phenols in water samples was developed using simultaneous derivatization and dispersive liquid- liquid microextraction followed by gas chromatography- flame ionization detection( GC- FID). In this method,800 μL acetic anhydride( derivatization agent) was injected rapidly into 5 m L water samples( p H = 7.00) in a test tube with conical bottom and derivatized 30 min under the temperature of 50 ℃.Then,200 μL dichoromethane( extraction solvent) and 10 μL methanol( disperser solvent) was injected into the solution and the mixture was gently shaken.After centrifugation of the cloudy solution,the derivatized analytes in the sedimented phase were determined by GC- FID. Under optimized conditions,the approach was applied to the determination of Phenols in water samples with a linearity range of 0.02~4.00 μg / m L. Correspondingly,the determination limit at an S / N of 3 were 1.98 μg / L.The recoveries of real samples at different spiked levels of Phenols ranged from 59.6% to 119.2% and the relative standard deviations less than 6.90%.