[Study on visible spectra of Victoria Pure Blue and its association complexes].
The visible spectrums of Victoria Pure Blue (VPB) and its association complexes were studied, and the chromogenic reaction of VPB with anions was also studied. The proton conduction constant of VPB in water solution was determined by plot method. The composition and stable constant were measured by equimolar continuous change method and the molar ratio method. The color of VPB in acid solution was light yellow while that of its association complex was pure blue. The pKh values of VPB BO, VPB R, VPB B and NB were 2.16, 1.32, 0.82 and 0.73 respectively. The molar ratio of association complex formed by the reaction of VPB BO with DBS was 1:1, while the ratio of VPB BO to [CdI4]2- was 2:1. The Kf (Stability constant) value of the two compounds was 1.5 x 10(6) and 6.0 x 10(12) respectively. The apparent molar absorptivity of them was respectively 4.7 x 10(4) L x mol(-1) x cm(-1) and 2.8 x 10(5) L x mol(-1) x cm(-1). It is clear that VPB is a high-sensitivity chromogenic reagent with fine analytical properties.
Shi
Wen-jian
WJ
College of Urban Construction, University of Shanghai for Science and Technology, Shanghai 200093, China.