二溴苯基荧光酮-溴化十六烷基三甲铵荧光熄灭法测定微量铋

Fluorescence Quenching Method for the Determination of Trace Bismuth With 2,6,7-Trihydroxy-9-(4,5-dibromophenyl)- fluorone and Cetyltrimethylammonium Bromide

本文研究了Bi(Ⅲ)与二溴苯基荧光酮(DBPF)和溴化十六烷基三甲铵(CTMAB)形成三元络合物导致体系荧光熄灭的特性和条件以及410哌啶树脂分离富集铋的方法。在pH2.8甲酸介质,λ_(ex)=535nm、λ_(em)=563nm条件下,体系产生的荧光熄灭程度最大。铋量的线性范围为0.02～0.4μg/ml。以1mol/L HCl介质,通过哌啶树脂交换柱,铋被吸附,用0.5％EDTA解吸,使铋与很多金属分离。方法用于地质样品中痕量铋的测定,结果满意。

A fluorescence quenching method for the determination of trace Bi and the separation and preconcentration of Bi by using 410 piperidine resin is reported. The method is based on the fluorescence quenching effect of 2,6,7-trihydroxy-9-(4,5-dibromophenyl)fluo-rone-cetyltrimethylammonium bromide(DBPF-CTMAB) due to formation of a non-fluorescent ternary complex, Bi-DBPF-CTMAB. in pH 2.6 - 3. 0 HCOOH medium. The excitation and emission wavelengths are 535 and 563 nm , respectively. The linear relationship is obeyed in the range of 0. 02-0.4 μg/ml for Bi. Bi ( Ⅲ ) can be adsorbed on 410 piperidine resin in 2%-20%HCl medium. The adsorbed Bi is eluted with 0. 5% EDTA solution. The method has been applied to the determination of Bi in geological samples.