PACKED-COLUMN SUPERCRITICAL-FLUID CHROMATOGRAPHY MOBILE-PHASE ELIMINATION FOURIER-TRANSFORM INFRARED SPECTROMETRY EMPLOYING MODIFIED FLUIDS

A mobile phase elimination interface originally designed for liquid ch romatography-infrared spectrometry (LC-Transform) has been shown to pe rform exceedingly well for packed column supercritical fluid chromatog raphy-infrared spectrometry (SFC-FTIR). The separation of Irganox 1076 with 5% methanol modified CO2 is demonstrated. High quality spectral data were obtained throughout the 4000-700 cm(-1) range with no interf erence from methanol. The only modification to the commercially availa ble interface for SFC-FTIR was the insertion of a fixed integral restr ictor into the spray nozzle. The modified CO2 mobile phase is evaporat ed during the spray process, and the resulting chromatogram is deposit ed as a continuous track on an IR transparent (e.g., usually germanium ) flat surface (e.g., the sample collection disk). This track can then be scanned in a spectrometer to obtain spectra of the discrete sample components.