2,3,7-三羟基-9-(2,4-二羟基)苯基荧光酮荧光猝灭法测定微量铅

Determination of Trace Lead by Fluorescence Quenching Method with 2,3,7-Trihy-Droxy-9-(2,4-Dihydroxy)Phenyl Fluorone

在pH 7.60 NH3·H2O-NH4Cl缓冲溶液中,阳离子表面活性剂十六烷基三甲基溴化胺（Cetyltrime-thylammonium Bromide,CTMAB）存在下,利用Pb2＋与2,3,7-三羟基-9-（2,4-羟基）苯基荧光酮（2,3,7-trihy-droxy-9-（2,4-dihydroxy）phenyl fluorone,DHPF）配位产生荧光猝灭效应,建立了荧光猝灭法测定微量Pb2＋的新方法.实验结果表明,Pb2＋与DHPF形成1∶2配位化合物,pb2＋含量在0～1.60 μg/5 mL范围内与△F成线性关系,回归方程为△F=294.841 7×C＋4.715 6（C：μg/5 mL）,相关系数r=0.999 1,方法用于狗牙根中pb2＋含量测定,结果满意.

A new method for determining the content of trace Pb2＋ is established using fluorescence quenching effect, which is from the reaction of Pb^2＋ and 2,3,7-trihy-droxy-9-（2,4-dihydroxy） phenyl fluorone （DHPF） in pH 7.60 NH3 · H2O-NH4Cl buffer solution with the existence of cationic surfactant cetyl trimethyl ammo- nium bromide（CTMAB）. The experimental results show that the molar ratio of Pb^2＋ to DHPF is 1 ： 2, Pb^2＋ and △F have a linear relationship when the content of Pb^2＋ is in the range of 0-1.60μg/5mL. The regression equation is AF=294. 8417× C＋4. 7156（C： μg/5 mL） and the correlation coefficient is 0. 9991. With this method, satisfying results are gained in the determination of content of Pb^2＋ in Cynodon dactylon.