Simulation of chemical accidents and estimation of long-term transformation & decomposition products of chemical accident material

Abstract

The frequency of chemical accidents has increased dramatically as the amount of chemical handling in Korea has increased[1]. After the chemical accident, Korea government is not taking into account any secondary damage caused by decomposition or transformation products of the parent chemicals, and the controversy continues over what caused the damage to the crops. Several studies have attempt to identify these phenomena, however, fate of secondary decomposition products, types of transformation products, and accident materials in soil is not clear. Thus, mechanism and pathway study, which were degradation products reversely track down the parent materials while fundamentally addressing secondary damage, are necessary to clarify the phenomena. In this study, the protocol is designed toward chemical accident substances are directly contaminated with the soil, and then the decomposition of the chemical, the elution of cation and anion in the soil and the direct impact of accident materials on the soil were analyzed. Chemical accident materials, Toluene (C7H8), Phenol (C6H6O), Triethylamine (C6H15N), Ethyl acetate (C4H8O2), Ethylmethl ketone (C4H8O), Benzene (C6H6), Tetrachlorosilane (SiCl4), Nitric acid (HNO3), Hydrochloride acid (HCl), Ammonia (NH3) were selected considering accident frequency and handling volume. Non-contaminated soil was collected from the actual accident areas. The microorganism metabolites, decomposition, and transformation chemicals was detected and analyze by the Non-target screening unknown compounds method using GC/LC-MS [2]. The soil samples were extracted according to the polarity of the three solvents like hexane, methanol, and deionized water. Nitrogen evaporator applied to analyze the trace amount of metabolite remaining in the solvent, and then concentrated to 1 mL before analysis. The xylene and toluene were detected after toluene leakage (Fig. 1). After experiment leakage accident simulation, LC/MS analysis found that a different cluster was formed for triethylamine in the metabolite cluster (Fig. 2) [3]. The results of long-term decomposition products, which originated from chemical accident, will be fundamental information to decide influence of chemical accident on plant growth.