电感耦合等离子体质谱法测定水系沉积物中银铜砷锑铋镉

水系沉积物中银、铜、砷、锑、铋和镉等金属元素的准确测定,对地质找矿工作具有重要的指导意义。实验采用王水于水浴条件下溶解样品,通过选择适宜的同位素以及选用干扰元素校正方程克服了质谱干扰,利用仪器软件在线校正了氯离子对砷的干扰,以2%~3%(V/V)王水为测定介质,建立了电感耦合等离子体质谱法(ICP-MS)测定水系沉积物中银、铜、砷、锑、铋和镉6种元素的方法。在优化的实验条件下,各元素校准曲线线性相关系数均在0.9990以上,方法检出限为0.0028~0.045μg/g,测定下限为0.008~0.13μg/g。采用实验方法测定水系沉积物实际样品中银、铜、砷、锑、铋和镉,测定结果分别与采用交流电弧发射光谱法(ES)测定银,原子荧光光谱法(AFS)测定砷、锑、铋,火焰原子吸收光谱法(FAAS)测定铜,石墨炉原子吸收光谱法(GF-AAS)测定镉的结果基本一致;测得结果的相对标准偏差(RSD,n=11)为0.28%~2.0%。将实验方法应用于水系沉积物标准物质分析,银、铜、砷、锑、铋和镉测定结果的相对标准偏差(n=12)为0.45%~6.0%。

Determination of silver,copper, arsenic,antimony, bismuth and cadmium in stream sediment by inductively coupled plasma mass spectrometry

The accurate determination of silver, copper, arsenic, antimony, bismuth and cadmium in stream sediment has important guiding significance for the geological prospecting. Sample was dissolved with aqua regia in water bath. The mass spectrometry interference was eliminated by selecting proper isotopes and using correction equations of interference elements. The interference of chlorine ion with the determination of arsenic was corrected online using instrumental software. The determination method of six elements (including silver, copper, arsenic, antimony, bismuth and cadmium) in stream sediment by inductively coupled plasma mass spectrometry (ICP-MS) was established in 2%-3% (V/V) aqua regia as the determination medium. Under the optimized experimental conditions, the linear correlation coefficients of calibration curves of elements were higher than 0.9990. The detection limit was 0.0028-0.045μg/g, and the low limit of determination was 0.008-0.13μg/g. The contents of silver, copper, arsenic, antimony, bismuth and cadmium in actual samples of stream sediment were determined according to the experimental method. The found results were consistent with those obtained by other methods: alternating current (AC) arc emission spectrometry (ES) for silver, atomic fluorescence spectrometry (AFS) for arsenic, antimony and bismuth, flame atomic absorption spectrometry (FAAS) for copper, and graphite furnace atomic absorption spectrometry (GF-AAS) for cadmium. The relative standard deviations (RSD, n=11) of determination methods were between 0.28% and 2.0%. The proposed method was applied for the analysis of certified reference materials of stream sediment. The RSDs (n=12) of determination results for silver, copper, arsenic, antimony, bismuth and cadmium ranged from 0.45% to 6.0%.