CHEMOMETRIC METHODS TO ENHANCE SPECTRA QUALITY AND EVALUATE DATA OBTAINED BY A NOVEL LASER-BASED IR TRANSMISSION SETUP FOR PROTEIN ANALYSIS

ALCARAZ M R; SCHWAIGHOFER A; GOICOECHEA, H C; LENDL B

Congreso; XVIII CAC 2016; 2016

Chemometrics has been proved to be an excellent complementary tool in several research fields. Incombination with advanced instrumentation technology, it could significantly improve the performance ofanalytical methods. In the analysis of protein secondary structure by infrared spectroscopy, the limits of themethod are defined by the high absorption of the solvent (i.e. water) as well as the low emission powers ofthe thermal light sources commonly employed in conventional FTIR spectrometers. Recently, a novel IRtransmission setup has been developed, employing an external cavity-quantum cascade laser (EC-QCL) aslight source that provides spectral power densities several orders of magnitude higher than thermal sources.In spite of being commercially available, these new light sources still suffer from imperfections in the tuningmechanism and shifts in the mode-hope fine structure of the emission curve within consecutive scans. Toovercome this constant and variable offset between scans, correlation optimized warping (COW) was applied.This well-known algorithm, previously employed for spectra and chromatographic peak alignment, is hereused to eliminate high noise levels in absorbance spectra obtained by QCL-IR spectroscopy [1].Furthermore, to showcase the potential and quality of the IR absorbance spectra obtained by