两种标准曲线法测定土壤中10种重金属元素
2021-04-06曹晓雅何芳贾长城王亚婷杜朋
曹晓雅 何芳 贾长城 王亚婷 杜朋



摘 要:采用混合酸+王水的湿法消解模式,对土壤和水系沉积物的标准物质进行消解,利用电感耦合等离子体质谱仪测量标准物质中10种重金属元素(Ba、Ce、Co、Cs、Cu、La、Ni、Pb、Sc、Sr)的含量,选用103Rh、185Re作为内标元素补偿基体效应和灵敏度漂移。结果表明:测量结果与标准值相符,以标准物质绘制标准曲线所测结果的准确度范围为0.0002~0.05,精密度范圍为0.46~8.72,以标准溶液绘制标准曲线所测结果的准确度范围为0.0003~0.049,精密度范围为1.56~9.64,测量结果符合国家标准要求。测定北京地区的土壤样品,所测样品中10种重金属元素浓度的下限值和上限值范围分别为:Sc 6.26 ~16.9 mg·kg-1、Co 7.84 ~22.9 mg·kg-1、Ni 15.8 ~51.8 mg·kg-1、Cu 18.6 ~ 64.7 mg·kg-1、Sr 63.6 ~ 450 mg·kg-1、Cs 0.96 ~8.74 mg·kg-1、Ba 354 ~979 mg·kg-1、La 21.9 ~48.1 mg·kg-1、Ce 44.0~88.1 mg·kg-1、Pb 6.78~231 mg·kg-1。两种测试方法测定结果相对偏差的最大值均小于25%。
关键词:质谱法;土壤;重金属元素
Abstract: In this paper, the soil samples were dissolved by mixed acid-aqua regia. Trace elements (Sc, Co, Ni, Cu, Sr, Cs, Ba, La, Ce, Pb) were determined by inductively coupled plasma mass spectrometry method. The matrix were compensated with 103Rh and 185Re as the internal standard element effect and sensitivity drift. The results show that the measured values are consistent with the national standard values; the measured values of drawing standard curve with reference materials show that the accuracy of each element is between 0.0002 and 0.05; the precision is between 0.46 and 9.35; the measured values of drawing standard curve with standard solutions show that the accuracy of each element is between 0.0003 and 0.049, and the precision is between 1.56 and 9.65. All meet the national standard. For the measured soil samples in Beijing areas, the results show: the content ranges of trace elements are (mg·kg-1) Sc 6.26 ~16.9, Co 7.84 ~22.9, Ni 15.8 ~51.8, Cu 18.6 ~ 64.7, Sr 63.6 ~ 450, Cs 0.96 ~8.74, Ba 354 ~979, La 21.9 ~48.1, Ce 44.0~88.1, Pb 6.78~231. The maximum relative deviation of the two methods is both less than 25%.
Keywords: inductively coupled plasma-mass spectrometry; soil; heavy metal element
电感耦合等离子体质谱仪的应用领域包括环境、食品药品、地质核能、生物和临床、黑色与有色金属材料、半导体等,其具有精密度高(李剑豪等,2020)、分析速度快、谱线简单(马留辉等,2020)、线性范围宽、检出限低(Eggins et al.,1997;刘颖等,1996;胡圣虹等,2000)等优点,能够同时测定样品中多种元素的含量(吴友玲,2019),在测定土壤中痕量元素领域已成为一项重要的技术手段(苏航,2019;蒙华毅等,2019;白金锋等,2011)。传统的样品前处理方法包括湿法消解、干灰化法、微波消解法等,与其他前处理方法相比,湿法消解具有适应性强、成本低、重现性好(杜洁等,2018)、检出限低、结果准确以及便于多元素同时测定等优点,适用于大多数土壤和沉积物样品中痕量元素的分析。
本文利用混合酸(HFHNO3HClO4=541)+王水……
