Studies in detoxication. 19. The metabolism of benzene. I. (a) The determination of phenol in urine with 2:6-dichloroquinonechloroimide. (b) The excretion of phenol, glucuronic acid and ethereal sulphate by rabbits receiving benzene and phenol. (c) Observations on the determination of catechol, quinol and muconic acid in urine

Abstract

A quantitative study was made of the excretion of phenol, glucuronic acid and ethereal sulfate by rabbits receiving oral doses of benzene or phenol. A new colorimetric method for the estimation of free and combined phenol in urine is based on steam distillation of phenol from urine and detn. of phenol in the distillate by means of the blue color with 2:6-dichloroquinonechloroimide under specified conditions. Normal human urine contains about 5-10 mg. of total phenol/1, in a conjugated form, whereas rabbit urine contains 2-6 mg. free and 10-13 mg. total phenol/1. About 21% of admd. benzene is excreted as phenols, 9.2% as phenol and 11.5% as other phenols; 9.5% of the benzene fed is excreted as ethereal sulfates and 11.2% as glucuronides. Only traces of free phenol are excreted. When phenol is fed to rabbits it is largely excreted as phenylglucuronide and phenylsulfuric acid, but some is oxidized to quinol which is excreted conjugated. Only small amts. of free phenol are excreted. Attempts to estimate catechol, quinol, and cis-cis and trans-trans muconic acid in urine were unsuccessful.