Spectrophotometric Determination of Triose Reductone by Using p-Aminobenzoic Acid

Abstract

p-Aminobenzoic acid (PABA) reacts with triose reductone (TR) to form two yellow condensates, consisting of rnonoanil and dianil whose molar ratio of TR to PABA, being 1: 1 and 1: 2, respectively, and whose absorption maxima in dimethyl sulfoxide (DMSO), being 365 nm and 430 nm, again respectively. The amount of TR was determined by the absorbance at the maximum absorption value ADD: N°=430 nm and el'allg= 7.0 x 1O^2-. When 2.0 to 12 pg of TR was allowed to react with 3.0 ml of 1 N-HCl solution contaning 0.1 moli/ PABA, only dianil was formed. This is the specific reaction of PABA toward TR among various reductones. On the basis of these results, the procedures for the determination of TR were recomended as follows: The solution (1.0 ml), containing 2.0 to 12 pg of TR was added to the solution (3.0 ml of 1N HCl) containing 0.1 molf/ PABA at 20°C and 5.0 ml of DMSO was added to the reaction mixture after 30 min. The solution was diluted to 10 ml with H₂0 and its absorbance was mesured at 430 nm against the blank. Several substances such as L-ascorbic acid, reductic acid, sugers, other organic acids, aldehydes, and metal ions except for Cu", Fe", Mn²⁺, and Hg²⁺ did not interfere with the determination of TR.