Flow analysis with FTIR-spectroscopic detection in aqueous media

The thesis concentrates on the development of new analytical systems based on the hyphenation of a FTIR-spectrometer with flow analysis (flow injection analysis, sequential injection analysis, HPLC) systems for the analysis of aqueous samples. Due to the high IR-absorption of water specialized IR-detection cells were developed for the measurement in transmission mode, based on standard flow through cells equipped with optical filters and on miniaturized fiber optic detection cells. The developed systems were applied to the determination of enzyme activities and the simultaneous determination of several enzyme activities with an one-step assay was shown. Furthermore, chemometric data evaluation methods were used for the simultaneous quantification of sugars, wine components (up to nine constituents with one spectroscopic measurement) and glucose in whole blood. All chemometric methods relied heavily on newly developed methods for automated preparation of calibration mixtures, enabled by the highly accurate sequential injection systems used. The hyphenation of micromachined enzyme reactors with the fiber optic transmission cell was the first example of a micro-total analysis system with FTIR-detection and with an improved cell sample volumina in the sub-μl were feasible. (author)