Gas Chromatographic Determination of Acyclic and Cyclic Organic Carbonates in Aqueous Environment
摘要
Procedures for the determination of organic carbonates (acyclic and cyclic) in aqueous media are proposed. It is found that headspace extraction is the most suitable method for extracting acyclic carbonates, while salting-out solvent extraction is the most suitable method for extracting cyclic carbonates. The conditions for the extraction methods are selected and optimized. The detection limits are 0.06–0.07 mg/L for acyclic carbonates and 0.5–1.5 mg/L for cyclic carbonates. The procedures are simple, do not require complex sample preparation, and the error in results does not exceed 10%. The residual content of organic carbonates in solutions of distilled or seawater after exposure to open air at 25°C is studied. It is found that, regardless of the density of the aqueous medium, acyclic carbonates do not undergo any transformations in the aqueous medium but instead migrate to the air phase, propylene and ethylene carbonates remain unchanged in the aqueous medium, while vinylene carbonate does not migrate to the air but undergoes chemical transformation in the aqueous phase.