An on-line supercritical fluid extraction multidimensional chromatographic system (10) and method is described which provides a cell (16) for extracting a target compound in supercritical fluid, and a restrictor interface (26) for trapping the extracted target compound while decompressing and venting the supercritical fluid. A pump (34) and valve (24) arrangement is provided to convey the trapped target compound through a micro LC column (36) for separating (and detecting) constituents of interest from interfering species, and ultimately introducing constituent of interest into a gas chromatograph (40) for analysis. The system is characterized as being ''on-line'' in that fluid communication is provided between all of the system components and the process is continuous. Similarly the system is characterized as being ''multidimensional'' in that both liquid and gas chromatographic techniques can be employed in tandem to provide analysis, selectivity and sensitivity in the parts per billion range.