Development of Environmental Analysis Methods Using Supercritical Fluid Extraction and Supercritical Fluid Chromatography

Supercritical fluid chromatography (SFC) was first attempted in 1962 [1]. Although several papers on SFC were published during the subsequent two decades [2], their content did not encourage many researchers to investigate this technique. After the introduction of fused-silica capillary SFC in the early 1980s [3], many papers describing fundamental studies as well as application studies appeared. Today, SFC is recognized as being a separation technique that acts as a bridge between GC and HPLC. Analytical supercritical fluid extraction (SFE) was demonstrated in the mid-1980s [4]. Since then, the number of papers describing the use of this technique has steadily increased. Because of the preferable properties of supercritical fluids as an extraction medium, SFE is a useful alternative to conventional solvent extraction as well as an “environmentally friendly” technique. The author and coworkers have made efforts to develop SFE and SFC. In the field of environmental analysis, we developed electron-capture detection (ECD) in SFC for the highly sensitive and selective detection of polychlorinated biphenyls (PCBs) [5] and organochlorine pesticides [6]. For accurate quantification by SFE, we investigated the effects of operation parameters and the sample matrix on extraction efficiency using organochlorine pesticides in carrots [6], herbicides in soil [7, 8] and PCBs in sediment [9] as target analytes. In addition, we applied an optimized SFE method for PCBs to the production of sediment certified reference materials (CRMs) for which accurate quantification methods were needed to determine certified values [9, 10]. We also demonstrated rapid quantification of thiolcarbamate herbicides in soil using an on -line SFE/SFC system [8]. This paper briefly overviews fundamental and application studies by the author’s group on the development of environmental analysis methods using SFE and SFC. Focusing Review