挥发排锑-电感耦合等离子体质谱法测定铅锑精矿中铊

Determination of thallium in lead antimony concentrate using inductively coupled plasma mass spectrometry after antimony expelled by hydrobromic acid

采用盐硝混酸＋氢氟酸溶解样品,氢溴酸挥发除锑的方法,避免高含量锑在溶液中不稳定及对铊测定的干扰,采用电感耦合等离子体质谱法测定了铅锑精矿中铊的含量。铅锑精矿经过前处理后,样品溶液中锑的残留量均小于10μg/m L。选择铱作内标,将方法应用于实际样品中铊的测定,相对标准偏差小于5%,回收率为97.2%-107%,选择6家试验室协同验证,经统计检验测试结果间无明显差异。方法适用于铅锑精矿中铊的测定。

High content of antimony iseasily hydrolyzed in the sample preparation of lead antimony concentrate which will also lead to a heavy interference in the determination using mass spectrometry. To avoid the problems, a test portion of lead antimony concentrate was dissolved using hydrochloric acid, nitric acid and hydrofluoric acid, followed by expelling antimony with hudrobromic acid, then the content of thallium was determined using inductively coupled plasma mass spectrometry. Results showed that after the expelling, the concentration of antimony was less than 10μg/mL in the sample solution. Under the instrumental conditions, iridium was used as internal standard substance, and the content of thallium in lead antimony concentrate was determined. The relative standard deviation was less than 5% , and the recoveries were between 97.2% and 107%. Six different departments were sele,eted for co-verification. Coehran test was operated for the results of six departments, and showed that these results had no significant difference, indicating that this method is applicable in the determination of trace thallium in lead antimony concentrate.