Comparison of ion mobility constants of selected drugs after capillary gas chromatography and capillary supercritical fluid chromatography.

Several test compounds were introduced into a unidirectional flow Ion mobillty spectrometer by both gas chromatography (GC) and supercritical fluld chromatography (SFC). The test samples were drugs from three general classes, opiates, benrodiazoplnones, and steroids. Drm spectra were collected for each compound by Fourier transform ion moblllty spectrometry. The drlft veioclty data for each compound was corrected for temperature and pressure dlfferences by conversion to reduced mobllity values, K,. Agreement of KO values for each method confkmed that the mobility of product ions In the unldirectlonai flow ion mobility spectrometer is independent of the introduction method. I n addition, drift tknes of the reactant ions In the spectrometer were compared for conditions of the presence of a contaminating CO, flow and the absence of any CO, flow. I t was found that there were no differences In the mobliitles of the reactant ions caused by CO, contamination, Indicating that the identities of the reactant ions were not affected by CO, flow.