background: benzene, toluene, ethylbenzene and xylene (btex) are the most important toxic volatile compounds in the air and could be easily absorbed through the respiratory tract. in recent years, the risk of exposure to btex compounds, especially benzene as a carcinogen, has been considered in petroleum depot stations. objective: to assess the occupational exposure of petroleum depot workers i...

In two separate experiments 10 healthy men each were exposed at rest in an exposure chamber to about 200 ppm toluene in the air. Hippuric acid, o-, m-, p-cresol, and phenol in urine were detected by capillary gas chromatography at the beginning and at the end of exposure, and at variable times after the cessation of exposure. In addition toluene in blood was determined at the same intervals. Th...

Previous studies from this laboratory have shown that p-aminohippuric acid is formed from p-aminobenzoic acid and glycine by liver slices (1) and homogenates under aerobic conditions, or anaerobically with adenosinetriphosphate (ATP) as the source of energy (2, 3). Similar observations on the synthesis of hippuric acid have been briefly reported (4). These studies suggested the format,ion of a ...

Workers at a printing plant exposed to low concentrations of toluene (43-401 mg/m3, median 155 mg/m3) had increased urinary D-glucaric acid (3.55-5.12 mmol/mol creatinine) excretion at the end of the shift compared with controls (2.45-3.35 mmol/mol creatinine). No increase was found after the summer holiday (1.92-2.89 mmol/mol creatinine) but excretion had increased two weeks later (4.05-5.55 m...

background : evaluation of exposition to volatile organic compounds (voc) and compare urinary level of urinary biological exposure index in sweepers in west of iran . methods: this study was carried out on 40 street sweepers and 40 non-exposed as control group living in hamadan city, west of iran. voc was analyzed using gas chromatography equipped with a flame ionization detector (fid). the uri...

In the literature one finds comparatively few references to the fate of the benaoic acid derivatives in the animal body, and even some rather conflicting statements regarding several of the corresponding hippuric acids. The object of our work, therefore, was to prepare the o-, m-, and p-chloro-, bromo-, and iodobenzoic acids, and, by feeding these substances to dogs and rabbits, to compare the ...

Synthesis of p-aminohippuric acid (PAH) from p-aminobenzoic acid (PAB) in animal liver slices and homogenates has been shown to resemble closely, both chemically and thermodynamically, the synthesis of peptides (1-3). This reaction has been utilized in the hippuric acid synthesis test for liver function since 1933 (4) and has found wide clinical application (5-7). Hippuric acid, however, must b...