Studies of volatility and vapour diffusion of chemicals with low volatility in the air

The results of the work give an overview of the phenomenon of volatility and one-dimensional diffusion of toxic substances with a volatility range from 500 to approx. 1100 mg/m3 , in relation to chemical warfare agents. The purpose of this work was to initially investigate the diffusion rate of lowvolatile substances in laboratory conditions, with the best possible representation of real conditions. The obtained results allowed us to assess potential contamination with such substances at a height of up to 150 cm from the surface of the emission source. For this reason, there was built an apparatus for taking gaseous samples at various distances from the emission source of the tested substance. Nontoxic sulfur mustard imitators of similar volatility were used for the experiments: dodecane, dimethyl glutarate, diethyl succinat, and dibenzyl ether. For each of these substances, the concentration of saturated vapour was determined and the time to achieve the liquid-vapour equilibrium in various configurations of research equipment was estimated. The analyses of the concentrations of the tested substances in the air were carried out using a gas chromatograph coupled with an atomic emission detector. The studies have shown that substances with low volatility can quickly rise to high altitudes.