单提取法-动能甄别型碰撞模式-电感耦合等离子体质谱(ICP-MS)法测定土壤中8种有效态元素的含量

Determination of Eight Available Elements in Soil by Inductively Coupled Plasma Mass Spectrometry with Single Extraction Method-Kinetic Energy Discrimination Collision Mode

鉴于电感耦合等离子体原子发射光谱(ICP-AES)法测定二乙烯三胺五乙酸-三乙醇胺-氯化钙(DTPA-TEA-CaCl2)单提取液中有效态含量时,对极低含量Cd、Co有效检出能力不足,以及在测定批量样品时矩管和中心管易积盐影响测定准确度的情况,按照HJ 804—2016《土壤8种有效态元素的测定二乙烯三胺五乙酸浸提-电感耦合等离子体发射光谱法》中样品前处理方式,即以二乙烯三胺五乙酸-三乙醇胺-氯化钙(DTPA-TEA-CaCl_(2))为单提取浸提剂,土液比为1∶2,样品在20℃±2℃恒温环境中,于180 r/min振荡频率水平振荡2 h离心后过滤,取滤液2.5 mL,用3%HNO_(3)稀释10倍,在标准溶液系列中加入浸提剂进行基体匹配后,选择^(55)Mn、^(56)Fe、^(59)Co、^(60)Ni、^(65)Cu、^(66)Zn、^(114)Cd、^(208)Pb作为分析同位素,建立了氢-氦混合气动能甄别型碰撞模式(KED)下,电感耦合等离子体质谱(ICP-MS)法同时测定土壤中8种有效态元素含量的方法。在优化的实验条件下,校准曲线线性相关系数为0.999 2~0.999 9,检出限和定量限分别为0.001~0.016μg/g和0.004~0.064μg/g。按照实验方法测定土壤有效态成分有证标准物质和内蒙古河套地区实际样品,测定值与认定值或比对值基本一致,测定值的相对标准偏差(RSD,n=7)为2.1%~8.7%,测定值与认定值的相对误差绝对值(|RE|,n=7)为0.63%~8.42%。方法简便快捷、灵敏度高、准确度与精密度好,适宜批量样品的连续测定。

In view of the insufficient effective detection capacity for extremely low content Cd and Co determined by inductively coupled plasma atomic emission spectrometry(ICP-AES)in the single extraction solution of diethylene triamine pentaacetic acid-triethanolamine-calcium chloride(DTPA-TEA-CaCl_(2)),and the salt is easy accumulation in the rectangular tube and central tube during the determination of batch samples,which affects the accuracy of the determination.In this paper,according tothe sample pretreatment method in HJ 804-2016,the ratio of soil to liquid was 1∶2,the soil samples were leached on constant temperature oscillator with rate of 180 r/min at 20℃±2℃ for 2 hours,after shaking remove 2.5 mL filtrate and dilute 10 times with 3% HNO_(3).^(55)Mn,^(56)Fe,^(59)Co,^(60)Ni,^(65)Cu,^(66)Zn,^(114)Cd and 208 Pb were selected as isotopes for ICP-MS analysis,a method for the simultaneous determination of eight available elements in soil has been established by inductively coupled plasma mass spectrometry with hydrogen-helium mixture collision mode(KED).Under the optimized experimental conditions,the linear correlation coefficients of calibration curves was 0.9992-0.9999,and the detection limits and quantitative limits were 0.001-0.016μg/g and 0.004-0.064μg/g,respectively.According to the experimental method,the certified reference materials of soil available components and the actual samples in Hetao area of Inner Mongolia were determined,and the measured values were basically consistent with the certified values or the comparison values The relative standard deviation(RSD,n=7)of the measured value was 2.1%-8.7%,and the absolute value of relative error between the measured value and the certified value(|RE|,n=7)was 0.63%-8.42%.The method is simple,rapid,sensitive,accurate and precise,and suitable for continuous determination of batch samples.