报道了采用微波消解-电感耦合等离子体质谱法(ICP—MS)测定云浮黄铁矿中钒、铬、钴、镍、铜、锌、砷、硒、锶、钼、银、镉、锑、钡、铊、铅等16种重金属元素。重点研究了消解体系以及影响测定的因素,包括多原子离子干扰和样品的基体干扰。研究表明:选用HNO3-H2O2作为消解体系,消化效果较好。在动态反应池内引入NH3,可有效消除多原子离子干扰;样品中基体的盐度小于2.0g/L和基体铁的浓度小于1.0g/L时,不影响测定结果;采用基体稀释与内标法联用的方式克服基体效应所带来的干扰。该方法的检出限在0.008~0.32μg/L之间。分别对含40.0μg/L重金属元素的标准样品平行测定7次,相对标准偏差在0.8%~4.8%之间。方法应用于黄铁矿样品中重金属元素的测定,回收率为92.3%~109.0%。
A method for simultaneous determination of sixteen trace heavy metal elements (HMEs) in pyrite using inductively coupled plasma mass spectrometry(ICP-MS) with microwave digestion was developed. The sample was directly dissolved in nitric acid and hydrogen peroxide (5+ 1) by microwave digestion without other pretreatment. Interference mainly from polyatomic ions and sample matrixes in the determination of the elements was thoroughly investigated. The results showed that the interference from polyatomic ions was eliminated by introducing ammonia gas in dynamic reaction cell. Moreover, when the salinity was less than 2.0 g/L and iron concentration was less than 1.0 g/L, the interference couldn't affect the analysis of these elements . The interference from matrix was also eliminated by using matrix dilution and internal standard method. The detection limits were from 0. 008 to 0. 32 μg/L for sixteen HMEs and the relative standard deviations were bettween 0. 8%-- 4.8% for 40.0 μg/L standard samples(n=7). The proposed method has been applied for the determination of sixteen HMEs in pyrite samples with the recoveries of 92.3%-109.0%.