离子色谱法测定土壤水溶性三氟乙酸的方法研究

Study on the Method of Determination of Water-solubleTrifluoroacetic Acid in Soil by Ion Chromatography

研究了测定土壤中水溶性三氟乙酸(TFA)的分析方法。目的:建立离子色谱法测定土壤中水溶性三氟乙酸的含量。方法:色谱柱采用分析柱DionexTMIonPacTMAS11-HC(?4 mm×250 mm),保护柱DionexTMIonPacTMAG11-HC(?4 mm×50 mm),流动相:10 mmoL/L氢氧化钾,流速:1.0 mL/min,柱温:30℃,进样量:250μL,抑制器电流:25 mA,电导检测器。结果:三氟乙酸在5.0~100.0μg/L范围内,线性关系良好,r=0.9998;当样品量20.0 g时,三氟乙酸的检出限为1μg/kg,测定下限为4μg/kg;实际土壤样品测定精密度为10%、3.7%,实际土壤样品测定回收率为82.6%~92.2%。结论:此方法具有前处理操作快速、简单,准确率高等优点。

An analytical method for the determination of water-soluble trifluoroacetic acid(TFA)in soil was studied.(Objective)Ion chromatography was established to determine the content of water-soluble trifluoroacetic acid in soil.(Methods)The analytical column Dionex IonPac AS11-HC(∅4 mm×250 mm),the guard column Dionex TM IonPac TM AG11-HC(∅4 mm×50 mm),mobile phase:10mmol/L potassium hydroxide,flow rate:1.0 mL/min,column temperature:30℃,injection volume:250μL,suppressor current:25 mA,conductivity detector.(Results)The linear relationship of trifluoroacetic acid in the range of 5.0~100.0μg/L was well,r=0.9998,and the detection limit of trifluoroacetic acid was 1μg/kg and 4μg/kg when the sample volume was 20.0 g.The precision of the actual soil samples was 10%and 3.7%,and the recovery rate of the actual soil samples was 82.6%-92.2%.(Conclusion)This method has the advantages of fast and simple pre-processing operation and high accuracy.