ZONE TRANSFER TECHNIQUE FOR DIFFUSE REFLECTANCE FOURIER-TRANSFORM INFRARED SPECTROMETRY OF ANALYTES SEPARATED BY THIN-LAYER CHROMATOGRAPHY

Separated zones on a thin-layer chromatographic (TLC) sheet which consists of a liquid-permeable support are transferred to a layer of KBr powder on the TLC sheet. No loss in chromatographic resolution after the transfer was found. The TLC sheet is placed in a diffuse reflectance attachment with a scanning sample stage. A smooth and continuous reconstructed IR chromatogram can be obtained while moving the sample stage at a constant rate. After acquiring the IR chromatogram, high signal-to-noise ratio spectra for separated zones can be obtained at any selected resolution by relocating the IR beam on selected positions of the KBr layer and measuring each zone again or, if high signal-to-noise ratio spectra are not required, then by Fourier transformation of the interferograms originally collected for the chromatogram to give medium signal-to-noise spectra.