在硫酸介质中,基于痕量钼(VI)对溴酸钾氧化二氯荧光素褪色反应的催化活性,建立了催化动力学荧光法测定钼(VI)的新方法.对该催化反应的反应条件进行了系统考察,实验结果表明,最优化条件下,在7×10^-7-1×10^-5mg/m L浓度范围内,钼(VI)与荧光强度表现出较强的线性关系,回归方程:ΔIF=2.178c+32.72(c:×10^-6mg/m L),相关系数:r=0.9918.方法的检出限为9×10^-8mg/m L,对1×10^-6mg/m L的钼(VI)标准溶液进行了11次平行测定,相对标准偏差(RSD)为0.6%.该方法用于人发中痕量钼(VI)含量的测定,回收率为93.1%-110%.
A new catalytic kinetic spectrofluorimetric method is proposed for the determination of trace Mo( VI) based on the catalytic effect of trace Mo( VI) on the oxidation fading of dichlorofluorescein B by potassium bromate in H2SO4 medium. The effecting factors are investigated. Under the optimal conditions,within a concentration range of 7 × 10- 7~ 1 × 10- 5mg / m L,the Mo( VI) and fluorescence intensity have a good linear relation. The regression equation is ΔIF= 2. 178 c + 32. 72( c: × 10- 6mg / m L)with the correlation coefficient of r = 0. 9918. The detection limit is 9 × 10- 8mg / m L and the relative standard deviation( RSD) is 0.6% for 1 × 10- 6mg / m L Mo( VI) solution( n = 11). When the method is applied to the determination of trace Mo( VI) in hair,the recovery rate is between 93. 1% ~ 110%.