摘要:
采用水浴加热低温消解浸取铁矿石样品,顺序注射-氢化物发生原子荧光光谱法测定铁矿石样品中砷和汞的含量。选择了消解试剂,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、溶液酸碱比例、样品中的主要基体元素等因素对砷和汞测定的干扰,并确立了适宜的测定条件。砷浓度在0~100 μg/L与荧光强度呈良好的线性关系,砷的检出限为0.06 μg/L;Hg浓度在0~10 μg/L与荧光强度呈良好的线性关系,汞的检出限为0.05 μg/L。砷的回收率可达98.0%~110.0%,相对标准偏差小于3.56%;汞的回收率可达90.0%~105.5%,相对标准偏差小于2.87%。方法用于分析实际样品,测定值与密封微波消解法结果一致。
Abstract:
A convenient method was established to determine arsenic and mercury contents in iron ores. The iron ores were dissolved in HNO3-HCl solution by water-bath digestion at low temperature, and the determinations of arsenic and mercury contents were performed by hydride generation-atomic fluorescence spectrometry with a sequential injection system. The choice of digestion reagents is discussed in this paper. Some important interference factors were studied to obtain the optimum measurement conditions, e.g the concentration of KBH4 solution, the flow rate of carrier gas, the flow rate of coolant gas, acid and acid-base proportion. The linear range was from 0 to 100 g/L for arsenic, and from 0 to 10 g/L for mercury. The detection limit of arsenic and mercury is 0.06 g/L and 0.05 g/L respectively. The method has been applied to determine arsenic and mercury contents in iron ores. Arsenic content is shown to have a RSD less than 3.56% and recovery of 90.0%-110.0%, and mercury content is shown to have a RSD less than 2.87% and recovery of 90.0%-105.5%. The results of actual samples with this method were in good agreement with those obtained by the airproof-microwave digestion method.
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