碱消解-离子色谱与电感耦合等离子体质谱(IC-ICP-MS)法测定土壤中的六价铬  

Determination of Hexavalent Chromium in Soil by Alkaline Digestion-Ion Chromatography and Inductively Coupled Plasma Mass Spectrometry(IC-ICP-MS)

作　　者：刘卫 林建 杨一 LIU Wei;LIN Jian;YANG Yi(Shanghai Institute of Chemical Industry Testing Co.,Ltd.,National Center for Quality Supervision and Testing of Chemical Fertilizers(Shanghai),Shanghai 200062,China)

机构地区：[1]上海化工院检测有限公司国家化肥质量监督检验中心(上海),上海200062

出　　处：《中国无机分析化学》2022年第1期8-12,共5页Chinese Journal of Inorganic Analytical Chemistry

基　　金：国家重点研发计划项目(2020YFC1807304)。

摘　　要：采用碱消解土壤溶液提取土壤溶液中的六价铬,用离子色谱(IC)进行分离,有效避免了高盐及焰色反应的干扰,电感耦合等离子体质谱(ICP-MS)法进行检测。研究了消解液使用量、消解温度、消解时间等因素,测定结果和火焰原子吸收光谱(FAAS)法进行对比。结果表明,当称样量为5.0 g,消解液40.0 mL,磷酸缓冲溶液0.4 mL,无水氯化镁0.4 g,消解温度在90~95℃范围内消解0.75 h能保证土壤中六价铬的完全提取。方法检出限为0.01 mg/kg,相对标准偏差为3.5%,土壤标准物质的回收率为92.4%;与FAAS法(检出限0.35 mg/kg,精密度为6.3%)相比,检出限更低,精密度更好,抗干扰能力强;通过实际样品的测定结果统计学检验,两种方法结果无显著性差异;方法适用于土壤中低浓度六价铬的测定。Hexavalent chromium in the soil was extracted with alkaline digestion solution,separated by ion chromatography and detected by ICP-MS.The method of IC-ICP-MS effectively avoids the interference of high salt and flame reaction by using ion chromatography separation.The consumption of digestion solution,digestion temperature,digestion time and other factors were studied,and the measurement results were compared with FAAS method.The results showed that when the sample weight was 5.0 g,digestion solution was 40.0 mL,phosphoric acid buffer solution was 0.4 mL,anhydrous magnesium chloride was 0.4 g,and digestion time was 0.75 hours in the range of 90—95℃,the extraction of hexavalent chromium from soil could be completed.The detection limit of the method was 0.01 mg/kg,the relative standard deviation was 3.5%,and the recovery of soil reference matter was 92.4%.Compared with FAAS method(detection limit 0.35 mg/kg,precision 6.3%),this method has lower detection limit,better precision and stronger anti-interference ability.There was no significant difference between the two methods through the measurement of actual samples and statistical tests.This method is suitable for the determination of low-concentration hexavalent chromium in soil.

关 键 词：六价铬 土壤 离子色谱-电感耦合等离子体质谱法 碱消解 火焰原子吸收光谱法 

分 类 号：O657.75[理学—分析化学] O657.63[理学—化学]