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

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(IC P-M S)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....

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

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.