Synthesis of 1-(4-Methyl-6-Hydroxyl-Pyrimidine)-3-(Phenyl-Azo) -Triazene and Its Chromatogenic Reaction with Copper

1-(4-methyl-6-hydroxyl-pyrimidine)-3-(phenyl-azo)-triazene (MHPPAT), as a chromogenic reagent， was synthesized and its chromatogenic reaction with copper was studied. In the presence of surface active agent Triton X100and in Na2B4O7NaOH medium at pH=11.0， MHPPAT forms a purple complex with Cu（Ⅱ）. The apparent molar absorptivity of the complex is 2.02×105 L·mol-1·cm-1 at 540 nm（λmax）. The molar ratio of Cu（Ⅱ） to MHPPAT is 1∶2. Beer′s law is obeyed in the range of 0～480 μg/L for copper. The method has been applied to the direct determination of copper in aluminium alloys with precision of less than 3%RSD (n=6).