BRIDGING THE AUTOMATION GAP BETWEEN SAMPLE PREPARATION AND ANALYSIS - AN OVERVIEW OF SFE, GC, GC-MS, AND HPLC APPLIED TO ENVIRONMENTAL-SAMPLES

The detection and analysis of contaminants in soils, sediments, and solid wastes is currently a common problem. This paper examines applying automated supercritical fluid extraction (SFE) systems to examples of common environmental problems: petroleum products from leaking underground storage tanks and polychlorinated biphenyls from oil. Contaminants are extracted using SFE and analyzed by gas chromatography (GC), high-pressure liquid chromatography (HPLC), and mass spectrometry GC-MS. The total petroleum hydrocarbon (TPH) extraction was performed according to the Environmental Protection Agency’s (EPA) Draft Method 3560. Work with polyaromatic hydrocarbons (PAH) is a first step toward deriving a similar EPA SFE method. The PCB from oil matrix work was done to explore whether SFE would decrease coextractant interferences with the GC-MS analysis relative to established manual procedures, thereby affording lower detection levels and improved quantitation. The following will be presented: a description of a fully automated system consisting of an SFE coupled to a GC (TPH assay), interlaboratory results for PAH (HPLC analysis), and a comparison of the extract cleanliness of PCB-containing fractions obtained with manual and SFE methods. © Oxford University Press 1993.