高压密封微波消解-氢化物发生原子荧光光谱法测定锰矿中砷和汞含量

来源期刊：冶金分析2010年第12期

论文作者：苏明跃 杨丽飞 郭芬

文章页码：39 - 43

关键词：高压密封微波消解； 顺序注射-氢化物发生原子荧光光谱法； 锰矿； 砷； 汞

Key words：high-pressure-airproof microwave digestion； sequential injection-hydride generation atomic fluorescence spectrometry； manganese ores； arsenic； mercury

摘    要：使用硝酸、盐酸、氢氟酸体系在高压密封微波消解器中完全消解锰矿样品,采用顺序注射-氢化物发生原子荧光光谱法检测样品中砷、汞含量。讨论了微波消解酸体系及用量的选择,研究了硼氢化钾浓度、载气流量、屏蔽气流量、溶液酸介质、载流溶液、溶液酸碱比例、样品中的主要基体元素等因素对砷、汞检测的影响,并确立了适宜的检测条件。砷浓度在0～100μg/L范围内与荧光强度呈良好的线性关系,砷的检出限为0.02μg/L;汞浓度在0～10μg/L范围内与荧光强度呈良好的线性关系,汞的检出限为0.05μg/L。采用本方法检测锰矿中砷、汞,砷的回收率可达105%～112%,相对标准偏差小于2.5%;测汞回收率可达91%～110%,相对标准偏差小于4.4%。使用该法分析参考物质和实际样品,分析结果与认定值和其他方法测定值一致。

Abstract: In this paper,a convenient method for the determination of arsenic and mercury in manganese ores was established.The manganese ores were completely dissolved in HNO₃-HCl-HF solution by high-pressure-airproof microwave digestion.Arsenic and mercury were determined by sequential injection-hydride generation atomic fluorescence spectrometry.The selection and dosage of acid for microwave digestion were discussed.Some important influencing factors were studied,e.g.the concentration of KBH₄ solution,the flow rate of carrier gas and shielding gas,acid medium,carrier solution,acid-base ratio,the main matrix elements in manganese ores,etc.The optimum process conditions were obtained.Linear range was 0-100 μg/L for arsenic,and 0-10 μg /L for mercury.Detection limit of arsenic was 0.02 μg/L and that of mercury was 0.05 μg/L.The method has been applied to the determination of arsenic and mercury in manganese ores.Relative standard deviation for determination of arsenic was 1ess than 2.5%,and recoveries were between 105-112%.Relative standard deviation for determination of mercury was 1ess than 4.4%,and recoveries were between 91%-110%.The determination results for certified reference materials and actual samples by this method were in good agreement with the certified values and those obtained by other conventional methods.