Application of an HPLC-FTIR modified thermospray interface for analysis ofdye samples

Previously, we developed a reversed-phase HPLC method compatible to high pe rformance liquid chromatography diffuse reflectance Fourier-transform infra red (HPLC-FTIR) thermospray interface for the analysis of dyes. Dye separat ion achieved with a mixed-mode (SCX-ODS) column using a small gradient (90 to 80% water with acetic acid) and pH 3.25; 10 to 20% acetonitrile was cons idered to be suitable for HPLC-FTIR. A constant-voltage setting for the the rmospray temperature (227 degreesC) was successfully used for this gradient condition. The HPLC-separated components deposited as a series of concentr ated spots on a moving tape were scanned by specially developed HPLC-FTIR s oftware. Excellent repeatability of the thermospray deposition FTIR chromat ograms and IR spectra was obtained. The interface-derived spectra of the se parated components of formulated and purified reactive dyes were compared a nd differences in spectral features were observed.