On‐line combination of liquid chromatography and capillary gas chromatography. Preconcentration and analysis of organic compounds in aqueous samples

Abstract

Abstract This paper describes the design of a new, versatile, and low‐cost on‐line LC‐GC interface that allows the fast and reliable introduction of large sample volumes onto a capillary GC column. The sample introduction procedure consists successively of: evaporation of the entire sample (LC fraction), selective removal of the solvent and simultaneously cold‐trapping of the solutes, splitless transfer of the solutes to the GC column, on‐column focusing, GC separation and detection. Quantitative and qualitative aspects of various experimental parameters are evaluated and optimum conditions are reported. The applicability of the method is demonstrated on a synthetic aqueous sample of chlorinated pesticides.