1,2-Propanediol Determination in working air with gas chromatography with mass spectrometer

Abstract

Propane-1,2-diol (propylene glycol, PG) is a color-less, strongly hygroscopic liquid used in the pro-duction of antifreeze fluids, polyester resins and detergents. The main use of propane-1,2-diol is in the cosmetic industry as an ingredient of creams, toothpastes, mouthwashes and deodorant sticks. It is also used in medicine, pharmaceutics, food and cleaning products. Propane-1,2-diol is used as a hygroscopic agent in the plastics industry, textile products and in manufacturing cigarettes. Recently, it is used as the main component of fluids used in electronic cigarettes. There are no reports in the literature on acute poi-soning with propylene glycol of people in occupa-tional exposure conditions. Clinical observations of people treated with propylene glycol applied as a drug solvent indicate a weak narcotic effect of the compound and mild irritation of the skin and con-junctives. The aim of this study was to develop and validate a sensitive method for determining concentrations of propane-1,2-diol in workplace air in the range from 1/20 to 2 MAC values in accordance with the requirements of Standard No. PN-EN 482+A1:2016-1. The study was performed using a gas chromatog-raphy (GC). A 6890N Agilent Technologies gas chromatograph with a 5973 mass spectrometry de-tector (MSD), HP-PONA (50 m; 0.2 mm; 0,5 μm) ca-pillary analytical column, autosampler and Chem-Station software were used for chromatographic separations. The method is based on the adsorption of inhalable fraction and vapors of propane-1,2-diol on glass fi-ber filters and XAD-7 resin, desorption with ace-tonitrile and analysis of the resulting solution with gas chromatographic with mass detection (GC/MS). The extraction efficiency of propane-1,2--diol from filters and resin was 97.3%. Samples of propane-1,2-diol can be stored in refrigerator for up to 28 days. Application of a HP-PONA capillary column enabled selective determination of pro-pane-1,2-diol in a mixture of acetonitrile, dichloro-methane, toluene and other compounds. The method is linear (r = 0.9992) within the work-ing range 10–500 μg/ml, which is equivalent to air concentrations range 4.4–222 mg/m3 for a 180-L air sample and 80-fold dilution. Limit of quantification (LOQ) is 1.303 μg/ml. The analytical method described in this paper ena-bles selective determination of inhalable fraction and vapors of propane-1,2-diol in workplace air in presence of other compounds at concentrations from 4.4 to 222 mg/m3 (1/20–2 MAC value). The method is precise, accurate and it meets the criteria for procedures for measuring chemical agents listed in Standard No. PN-EN 482+A1:2016-1. The method can be used for assessing occupational exposure to propane-1,2-diol and associated risk to workers’ health. The developed method of determining propane-1,2-diol has been recorded as analytical procedure (see appendix).