SPECTROPHOTOMETRIC DETERMINATION OF TARTARIC ACID WITH BETA-NAPHTHOL

Tartaric acid (50-800 μg) is reacted with β-naphthol (5 mg) in 90 % sulphuric acid (2 ml) for 30 min on a steam-bath. The solution is cooled and diluted to 25 ml with 90% sulphuric acid and the absorbance is measured at 603 nm. Several absorption maxima are observed and the ratio and intensity of these depend on the concentration of acid during and after the reaction, and on the β-naphthol concentration. All tartaric acid isomers give essentially the same colour and absorbance. Interference studies are reported. © 1969.