抄録
Hippuric acid excretion in the urine of workers after exposure to toluene, was assayed by Gaffney's method. The results obtained are as follows. (1) The determination of hhippuric acid in the urine was carried out by paperchromatography, spoting 0.1 ml of urine on the filter paper (40×40 cm) which was (developed in a solvent system: butanol, acetic acid, and water, (4: 1: 1). After drying, the color reaction was brought to completion, by spraying with 4 per cent solution of p-dimethylaminobenzaldehyde in acetic acid anhydride saturated with sodium acetate, and by heating in a drying oven for one minute at 135°C. The Rf value of hippuric acid contained in the urine was 0.8 coincided with that of pure hippuric acid. The absorption spectrum of the methanol eluate of the colored spot of the workers' urine corresponded also with that of pure hippuric acid. (2)The hippuric acid excretion in men administered orally with sodium benzoate showed the maximum value one hour later and ceased 4 hours after the administration. (3) In a plastic manufacturing factory using toluene as a solvent, a group of workers exposed to 50p.p.m. of toluene in the air excreted hippuric acid as much as 3.4 times the pre-exposure value, and in another group exposed to 20 p.p.m. it was 1.9 times. These results may indicate that excretion of hippuric acid in the urine is proportional to the concentration of toluene in the air. (4) At an autotricycle factory using the mixture of toluene and benzene (4:1), an increase of hippuric acid excretion in the urine of workers was recognized after exposure to this gas mixture.
