Biochemical Reagents Ortho Toluidine 2-Methylaniline 95-53-4

Biochemical Reagent Intermediates Pharma Named O-Toluidine

o-Toluidine (ortho-toluidine) is an organic compound with the chemical formula C7H9N.o-Toluidine is primarily used in the manufacture of dyes. o-Toluidine is highly toxic to humans when absorbed through the skin, inhaled as vapor, or swallowed. Acute (short-term) exposure of humans to o-toluidine affects the blood (i.e., methemoglobinemia), with clinical signs of central nervous system depression. The chronic (long-term) effects in workers exposed to o-toluidine include anemia, anorexia, weight loss, skin lesions, central nervous system depression, cyanosis, and methemoglobinemia. Animal studies indicate that chronic exposure to o-toluidine causes effects on the spleen, liver, urinary bladder, and blood. Occupational exposure to dyestuffs (including o-toluidine) is associated with an increased risk of bladder cancer. 2-Methylaniline hydrochloride (the hydrochloride salt of o-toluidine) was carcinogenic in rats and mice. o-Toluidine has been classified by EPA as a Group B2, probable human carcinogen.

Epidemiological evidence that occupational exposure to o-toluidine and aniline is associated with an increased risk of bladder cancer led to efforts to identify biomarkers of workplace exposures to these aromatic amines. For the determination of o-toluidine and aniline in worker urine specimens, a method using high performance liquid chromatography (HPLC) followed by electrochemical detection was developed. The limits of detection were 0.6 μg/l and 1.4 μg/l for o-toluidine and aniline, respectively. Recovery of o-toluidine and aniline from spiked urine averaged 86% and 93%, respectively, over a range of 4-100 μg/l. Reproducibility in the range 2-100 μg/l for analyses of split field samples was 13% (average RSD) for o-toluidine and 16% (average RSD) for aniline. Application of this method to pre- and post-shift samples collected from potentially exposed and unexposed workers indicated elevated concentrations of o-toluidine and aniline in urine from exposed workers. To develop methods for biomarkers of internal dose, o-toluidine binding to the blood proteins hemoglobin and albumin was investigated utilizing in-vivo (rodent) and in-vitro (hemoglobin and albumin) studies. Base-hydrolyzable protein adducts were analyzed by HPLC (fluorescence) and/or GC/electron capture (EC). The methods were compared for sample preparation requirements, selectivity and sensitivity. While the GC/EC method was more sensitive than HPLC, the presence of interfering peaks limited the utility of this approach. Results from these studies suggested that the HPLC method could be useful for determination of o-toluidine exposures in individuals acutely or chronically exposed to high levels.