The Study Of The Interface Adsorption Mechanism Of Chemical Warfare Agents Abandoned By Japanese

The Imperial Japanese forces buried or dumped a large number of chemical weapons into China without any treatment,leaving China still exposed to the danger of leaking chemical warfare agents.To elucidate the significance of the air-water interface in the atmospheric fate and transport of chemical warfare agent vapor,the air-water interface partition constant is required.In this work,to study the adsorption distribution behavior of chloroacetophenone(CN)and sulfur mustard(HD)in the water film,a new flow-tube reactor technique was developed.The reactor was able to control a thin water film with the thickness ranged from 100μm-5000μm.A thin aqueous film or ice film placed in the reactor was exposed to the vapor of the target agent.After the partition equilibrium was reached,the concentrations of the target agent in the gas phase and the aqueous film were measured separately to determine the interfacial partitioning of the aqueous film and the ice film.The quality control tests were first conducted to ensure the accuracy of the adsorption experiments.Validation experiments were then carried out using cyclohexanone.The cyclohexanone concentration was then plotted as a function of film thickness to obtain the partitioning constants.The cyclohexanone concentration was then plotted as a function of film thickness to obtain the partitioning constants.The air-water interfacial partition constant for cyclohexanone at 296 K is 2107.5.According to the temperature dependence of the interfacial partition constant,the solvation enthalpy and entropy of cyclohexanone were 4.8±0.5k J/mol,13.9±1.7 J/mol respectively.A direct immersion solid-phase microextraction procedure for the simultaneous analyses of 2-Chloroacetophenone and other three primary riot control agents: ochlorobenzylidene malonitrile,Dibenz(b,f)-1,4-Oxazepine,and oleoresin capsicum atμg/L concentration from environmental water was developed.Several parameters that influence the extraction effectiveness were investigated,including fiber type,extraction temperature,extraction time,starring rate,and salinity.Under the recommended conditions,the optimized method had reasonable linearity and accuracy.The determination coefficients for all compounds were larger than 0.99.The average recovery of this method ranged from 84% to 108.1%.The limit of detection for all the analytes ranged from 0.2 to 3 μg/L and the limit of quantification ranged from 1 to 10μg/L,respectively.A relative standard deviation from 3.0% to 4.3% could be achieved depending on the compounds.The procedure was applied to analyze all the four riot control agents simultaneously in several environmental samples,the recovery of the SPME-GC method for CN was ranged from 101.2%-124.9%.The SPME-GC method provides a solution for the quantification of CN.The concentration of CN in the gas phase and water film was analyzed by the method.In 298 K,the air/water interface partition coefficients of CN and in pure water,river water,and seawater were 1182.2± 49.9,1606.6 ± 101.3,and 408.9 ± 18.3,respectively.The dissolved organic matter,salinity,and surface tension of the environment water were analyzed.Experimental results indicated that the surface tension of the environment water directly determined the partitioning capacity of CN in the sample.The presence of trace surface active components in river water resulted in higher surface tension.This leads to the strongest adsorption of CN on air/river water surfaces.The high salinity of seawater results in significantly lower surface tension than pure water and river water.This leads to the weakest adsorption of CN on air/sea water surfaces.In 298 K,The air/water interface partition coefficients of HD and in pure water,river water and seawater were 157.2±9.3,93.2±9.7,154.3±9.4,respectively.The solvation enthalpy and entropy of HD were 3.3±0.1 k J/mol,-11.7±0.2 J/mol respectively.The same adsorption experiment was performed on the surface of an ice film at-5°C.The air/water interface partition coefficient of HD on the ice film was 127.4±12.9,indicating that the adsorption of QLL was similar to that on the surface of supercooled water.The results of this study would help to elucidate the effect of atmospheric water film on the gas-aerosol partitioning of CN and HD.The research can help to better understand the fate of CN and HD in the atmosphere,and to assess the environmental risks and human health effects of these agents.