【摘要】 研究了一种快速、灵敏的同时测定水中的As(Ⅲ)和As(V)的荧光新方法。在pH=6.5~7.5的缓冲介质中,利用2’,7’-二氯荧光素(DCF)作为荧光试剂,激发波长λex=510nm,发射波长λem=528nm下,As(Ⅲ)和DCF竞争碘,引起荧光强度的增强,从而测定痕量As(Ⅲ)。同时利用L一半胱氨酸还原剂将水中的As(V)还原成As(Ⅲ),从而测定As(Ⅲ)和As(v)的总量,差减间接测定As(V)。As(Ⅲ)浓度在4~180ng/mL范围内,相对荧光强度差值与As(Ⅲ)浓度呈线性关系,线性方程△F=7.82C+0.76,相关系数为o.9991,本法快速、简便、灵敏度高,已用于检测自来水和池塘水中痕量的As(Ⅲ)和As(V),回收率在96%~105%,结果令人满意。更多还原

【Abstract】 A rapid,simple and sensitive fluorimetric method has been developed for the determination of inorganic arsenic. The method is based on the competitive reaction of arsenite and 2’, 7’-dichlorofluorescein （DCF） as fluoregenic reagent（λem=510nm,λem:528nm）at pH 6.5～7.5 with iodine（I₂）to cause the increasing fluorescence intensity of the solution.Arsenate and other ions do not react with iodine.After reduction to the trivalentstate byusing L-cysteine,total arsenic is determined by specrofluorimeter.Arsenate concentration can be calculated by difference.The calibration graph is linear over the range 4～180ng/mL arsenite.The linear re,ressi on equation is △F=7.82C+0.76 and the relative coefficient is 0.9991.The detection limit is 0.6ng/mL arsenite.The recovery of this method for detecting arsenite is 96%～105%、he mathod has been applied Successfully to the determination of arsenite in tap and pool water.更多还原