叶酸荧光分光光度法测定Hg(Ⅱ)的研究

Determination of Mercury(Ⅱ) Based on Fluorescence Quench of Folic Acid

基于Hg(Ⅱ)对叶酸的内源性荧光的荧光熄灭作用,建立了测定微量Hg(Ⅱ)的荧光分析方法﹒选用p H为6.0的HAc-Na Ac缓冲溶液,最大激发与发射波长分别为277.0 nm和443.0 nm,叶酸浓度选用5.00×10-6mol/L,相对荧光强度与Hg(Ⅱ)浓度的对数呈良好的线性关系,测定Hg(Ⅱ)浓度的线性范围为(4.20×10-6-6.20×10-3)mol/L,检出限为1.30×10-7 mol/L,相对标准偏差为1.38%(n=11),加标回收率为95.6%-99.7%﹒该法具有良好的选择性,可直接用于测定环境水样中的Hg(Ⅱ)含量﹒

A simple and sensitive fluorescence quenching method for the determination of mercury （ Ⅱ） was reported. It was based on fluorescence quenching effect of mercury （Ⅱ） on folic acid. When the concentration of folic acid is 5.00×10^-6 mol/L in HAc-NaAc buffer solution of pH 6.0, the maximum excitation and emission wavelengths of folic acid are 277.0 nm and 443.0 nm respectively. There is a good linear relationship between the relative fluorescence intensity and the concentration of mercury （ Ⅱ ） ranged from （4.20× 10^-6 to 6.20×10^-3） mol/L, with detection limit of 1.30×10^-7 mol/L. The relative standard deviation （n=11） is 1.38%. The average recovery is 95.6%-99.7%. The method has a good selectivity, which can be applied to the direct determination of mercury （ Ⅱ ） in environment water.