2-Tolyloamine. Determination in workplace air

Abstract

o-Toluidine (2-TA) exists at ambient temperature as a light yellow liquid which rapidly darkens when exposed to air and light. It is used primarily in manufacturing dyestuffs, it is also used in the production of pesticides, rubber and in organic synthesis. 2-TA may cause cancer. The aim of this study was to determine concentrations of 2-TA in workplace air in the range from 1/10 to 2 MAC values. The study was performed using a liquid chromatograph (HPLC) with a diode array detector (DAD) with a column Ultra C18 (250 × 4.6 mm; 5 µm). This method is based on the adsorption of 2-TA on a glass fiber filter coated with sulfuric acid and extraction with sodium hydroxide solution. After derivatization with 3,5-dinitrobenzoyl chloride, 2-TA is analyzed as derivative with chromatography. The method was validated in accordance with Standard No. EN 482. The working range was from 0.05 to 1 mg/m3 for a 36 L air sample. The following validation parameters were determined: detection limit 3.48 ng/ml, determination limit 10.43 ng/ml, overall accuracy of the method 5.22%, relative total uncertainty of the method 11.45%. The analytical method described in this paper enables selective determination of 2-TA in workplace air in the presence of other substances at concentrations from 0.05 mg/m³ (1/10 MAC value). The method is precise, accurate and it meets the criteria for the procedures for measuring chemical agents listed in Standard No. EN 482. The developed method of determining 2-TA has been recorded as an analytical procedure (see Appendix).