新荧光试剂3—苯基—5—（2‘—羧基苯偶氮）绕丹宁的合成及荧光性质研究

Synthesis of a Fluorescent Reagent 3-Phenyl-5- (2'''' -carboxylphenylazo)rhodanine and Its Character

A fluorescent reagent, 3-phenyl-5-(2'-carboxylphenylazo)rhodanine (3PRACP), is synthesized. The reagent has been purified using column absorption chromatography.. Its constitution has been confirmed by elemental analysis, IR, HNMR and MS. 3PRACP reacts with Cu2+to form a chelate. To determine Cu2+ in pork and vegetable leaves, a sample (5g) was dried, carbonized, ashed, oxidized, calcinated and dissolved in HC1 (1:1) followed by dilution to 100 mL with H20. The solution (1 mL) was mixed with 0. 5 mL 3PRACP (2. 0 10-4 mol/L), 2 mL potassium hydrogen phthalate (C8H4O4HK)-NaOH buffer solution at pH5. 6, and made up to 25 mL with water; after heating in a boiling-water bath for 25 min and cooling, the fluorescence intensity was measured at 405 nm (excitation at 305 nm) (vs. the reagent blank). The calibration graph was rectilinear in the range of 0-1. 2 fug Cu2+/ 10 mL; the detection limit was 5*10-4 ug/g. Recovery was 97% -101%. Most foreign ions did not interfere with the determination of Cu2+.