Synthesis of a Multi-Halogenated Phenylfluorone Chromogenic Reagent and Spectrophotometric Determination of Trace Amount of Cadmium

A novel multi-halogenated phenylfluorone chromogenic reagent, 2′,4′-dichlorophenyl-4,5-dibromofluorone (DCDBPF) was synthesized. Cd(Ⅱ) could react with DCDBPF to form an stable color complex at ratio of 1:3 in pH 10 solution containing CTMAB-OP microemulsion. The λmax of the color complex found was 626nm and the apparent molar absorption coefficient found was 1.0×105mol-1·L·cm-1. Mass concentration of Cd(Ⅱ) followed the Beer′s law within 1.8 mg·L-1, with detection limit of 10 μ g·L-1. The proposed method was applied to the analysis of cuttlefish samples, giving values of recovery and RSD′s in the ranges of 95.2%-97.3% and 2.5%-4.8%, respectively.