[Zurück]

G. Quintas, B. Lendl, S. Garrigues, M. de la Guarida:
"Univariate method for background correction in liquid chromatography-Fourier transform infrared spectrometry";
Journal of Chromatography A, 1190 (2008), S. 102 - 109.

An univariate method is proposed for background correction in online gradient liq. chromatog.-Fourier transform IR (LC-FTIR) spectrometry using acetonitrile:water as mobile phase. The method is based on the calcn. of the ratio of absorbances (AR) at two characteristic wavenumbers for each spectrum. This parameter is subsequently used to locate the most appropriated eluent spectrum within a ref. spectra matrix (RSM) to be subtracted from each spectrum included in the sample chromatogram. To correct minor changes in eluent spectra intensity during the elution of analytes, a correction factor (Kf), defined as the ratio of the absorbance of the sample and the selected eluent spectrum at a defined wavenumber was detd. The performance of the procedure was evaluated by correcting an online gradient LC-FTIR injection of a mixt. of atrazine and diuron. Using the AR of the absorbance at 2248.6 and 2256.3 cm-1 and a Kf at 2248.6 cm-1, the correlation factors between FTIR spectra extd. at the peak apex from the LC-FTIR chromatogram and those obtained from pure pesticide stds. were 0.975 and 0.94 for atrazine and diuron, resp.