[Zurück]

G. Quintas, J. Kuligowski, B. Lendl:
"Procedure for automated background correction in flow systems with infrared spectroscopic detection and changing liquid-phase composition";
Applied Spectroscopy, 63 (2009), 12; S. 1363 - 1369.

This paper describes a partial least squares (PLS) based automatic procedure to correct for changes in the spectral contribution of the solvent or solvent mixts. from solute spectra recorded in these solvents. The procedure was developed for successful online Fourier transform IR (FT-IR) detection in gradient high-performance liq. chromatog. (HPLC) sepns. It requires a ref. FT-IR data set contg. all possible combinations of the expected variation in solvent compn. Furthermore, a spectral region (A) in these spectra is required where the solvents show absorption but the analytes do not. This is the case for the system ACN:H2O, an often-applied solvent mixt. in gradient HPLC, in the spectral region from 2300-2400 cm-1. By focusing on (A) the developed numerical method selects an appropriate background spectrum from the ref. data set, which is then subtracted from the analyte spectra. The method was programmed in Matlab and tested on different isocratic and gradient online reversed phase liq. chromatog.-Fourier transform IR spectrometry (LC-FT-IR) data sets. This work describes a successful method to perform eluent correction in online coupling of FT-IR spectrometry with gradient LC.