Maleic anhydride. Determination in workplace air

Abstract

Maleic anhydride is a crystalline solid. Maleic anhydride is an important intermediate in the chemical industry. It is harmful, irritating and sensitizing.The aim of this study was to develop a new method for the determination of maleic anhydride concentrations in workplace air in the range from 1/10 to 2 MAC values, in accordance with the requirements of the standard EN 482.Throughout the study, an Agilent Technologies series 1200 liquid chromatograph with a diode array detector (DAD) were used. The determination was carried out in the reverse-phase system (mobile phase: acetonitrile: solution of phosphoric acid) using an Ultra C18 column; dimensions: (250 × 4.6 mm) with dp = 5 μm, with precolumn, dimensions: 10 × 4 mm. The method was based on passing air through a glass fiber filter coated of 3,4-di-methoxybenzylamine. Samples were extracted with acetonitrile/ammonia and analyzed by HPLC-DAD.Validation of the method was carried out in accordance with European Standard EN 482. The following validation parameters were determined: measuring range: 0,05  1 mg/m3, limit of detection (LOD): 8,18 ng/ml, the limit of quantification (LOQ): 24,5 ng/ml, the overall accuracy of the method – 5,53%, the relative total uncertainty of the method – 12,02%.The analytical method described in this paper makes it possible to selectively determine maleic anhydride in workplace air in the presence of other substances at concentrations from 0,05 mg/m³ (1/10 MAC value). The method is characterized by good precision and accuracy and meets the criteria for the performance of procedures for the measurement of chemical agents, listed in EN 482. The developed method of determining maleic anhydride has been recorded as an analytical procedure (see appendix).