氢化物发生-原子荧光光谱法测定氟石中锑

Determination of antimony in fluorspar by hydride generation-atomic fluorescence spectrometry

采用HNO3、HF和HClO4消解氟石样品,通过加热挥发溶液中酸来控制反应体系酸度和去除试液中的F-,以L半胱氨酸为预还原剂,在60℃的温度下进行还原反应30 min,使溶液中的Sb（Ⅴ）还原为Sb（Ⅲ）,用氢化物发生原子荧光光谱法测定氟石中总锑含量.结果表明,F存在下,不会影响Sb（Ⅲ）的荧光强度,但会显著影响Sb（Ⅴ）的荧光强度,对总锑的测定存在干扰,添加L半胱氨酸或硫脲抗坏血酸,都不能消除F对Sb（Ⅴ）荧光强度的影响.方法检出限为0.024 μg/L.选取6种不同氟石样品进行测定,测定结果的相对标准偏差在3.3％～8.0％范围（n=6）,回收率在94％～106％之间,锑的测定值与ICP MS法测定值相符.

A new method was described for the generation-atomic fluorescence spectrometry. determination of total antimony in fluorspar by hydride The samples were dissolved in HNO3 ＋HF ＋ HClO4 mixed acid. Through heating until fumes of perchloric acid disappearing, system acidity was controlled and F- in the sample solution was removed. L-cysteine was added under 60 ℃ for 30 min to pre-reduce Sh from the pentavalent state to the trivalent state. The results indicated that F- could not interfere with the fluorescence signals of Sb（III） but could significantly interfere with the fluorescence signals of Sb（V）, i. e. , it would interfere with the determination of total antimony. Even after the addition of L-eysteine or thiourea-ascorbic acid, the interference of F in the determination of total antimony still could not be eliminated. The detection limit was 0. 024 μg/L. Six different fluorspar samples were determined. The relative standard deviations （RSDs） were 3.3%-8.0% （n=6）.