王水提取-电感耦合等离子体质谱法测定煤中微量银和镉

Determination of silver and cadmium in coal samples by inductively coupled plasma-mass spectrometry with aqua regia sample digestion

采用低温灰化煤炭样品,通过对比硝酸-高氯酸-氢氟酸混酸分解和王水提取2种预处理方法,确定用王水提取法预处理煤灰及采用电感耦合等离子体质谱法可同时测定样品中的微量银和镉。由实验可知,Ag和Cd的方法检出限分别为0.004μg/g、0.002μg/g;对煤炭、土壤及岩石标准物质进行分析,测定结果与标准值一致,7次平行测定的相对标准偏差为4.03%～6.34%;对样品进行加标回收实验,回收率在92%～112%范围内。实验证明,王水提取-电感耦合等离子体质谱法测定煤炭中痕量Ag和Cd具有简便快速、结果准确、精密度高的优点。

Utilizing coal samples undergoing low temperature ashing, after comparison of pretreatment methods： HN03 - HC104 - HF mixture decomposition and aqua regia sample digestion, this paper selected inductively coupled plasma-mass spectrometry （ICP- MS） method to determine the Ag and Cd in coal samples. The detection limit was 0. 004 μg/g for Ag and 0. 002 μg/g for Cd. This method was applied to the determination of trace Ag and Cd in reference material coal, soil and rock and the results were in agreement with the certified values. The RSD （n = 7） was between 4.03% and 6.34%. Experiment of recovering the labeled samples was carried out as well, and the recovery rate ranged from 92% to 112%. It was shown that this method was sensitive, accurate and rapid for the determination of trace Ag and Cd in coal samples.