Studies on an efficient method for determining 3,3’-dimethylbenzidine in the workplace air

摘要

Background: 3,3’-Dimethylbenzidene (DMB) is a substance classified into the group of carcinogens. The value of maximum admissibleconcentration for this substance in the workplace air is not specified in Poland. Bearing in mind that DMB is used in domesticcompanies there is a need to develop a sensitive method for determining 3,3’-dimethylbenzidine in the work environment. Material and Methods: The method consists in passing DMB-containing air through sulfuric acid-treated glass fiber filters, washingout the substance settled on the filter, using water and solution of sodium hydroxide, liquid–liquid extraction with toluene,replacing dissolvent with acetonitrile and analyzing the obtained solution. Studies were performed using high-performance liquidchromatography (HPLC) technique. An Agilent Technologies chromatograph, series 1200, with a diode-array detector (DAD)and a fluorescence detector (FLD) was used in the experiment. In the test, an Ultra C18 column of dimensions: 250×4.6 mm,particle diameter (dp) = 5 μm (Restek) was applied. Results: The method is linear (r = 0.999) within the investigated workingrange of concentration 1.08–21.6 μg/ml, which is equivalent to air concentrations 2–40 μg/m3 for a 540 l air sample. The limit ofdetection (LOD) of quantification determination is 5.4 ng/ml and the limit of quantification (LOQ) – 16.19 ng/ml. Conclusions: The analytical method described in this paper allows for selective determination of 3,3’-dimethylbenzidine in the workplace air inthe presence of 1,4-phenylenediamine, benzidine, aniline, 3,3’-dimethoxybenzidine, 2-nitrotoluene, 3,3’-dichlorobenzidine andazobenzene. The method is characterized by good precision and good accuracy, it also meets the criteria for procedures involvingthe measurement of chemical agents, listed in EN 482:2012. Med Pr 2016;67(1):43–50