Oxidative and reductive amperometric detection of phenolic and nitroaromatic compounds in packed capillary column supercritical fluid chromatography

Oxidative and reductive amperometric detection of phenols, nitroaromatic compounds and a cyclic ketone is demonstrated in packed capillary column supercritical fluid chromatography (SFC). The detection was performed in combination with isobaric, as well as, pressure programmed SFC separations, using a 25 mu m platinum electrode and carbon dioxide modified with a low concentration (1-5%) of methanol as the mobile phase. A relative standard deviation in the peak height of ca. 5% (n=10) was found for ng injections of analyte in combination with both oxidative and reductive detection. The detection limit was determined to be 250 pg for oxidative detection of 2.6-dimethylphenol and 100 pg for reductive detection of 1,3-dinitrobenzene. (C) 1997 Elsevier Science B.V.