MULTICOMPONENT ASSAY FOR BLOOD SUBSTRATES IN HUMAN PLASMA BY MIDINFRARED SPECTROSCOPY AND ITS EVALUATION FOR CLINICAL ANALYSIS

An analytical multicomponent method for the blood substrates total pro tein, glucose, total cholesterol, triglycerides, and urea in human EDT A plasma by FT-IR spectroscopy is described. The spectra were obtained with the use of the attenuated total reflection technique. Partial le ast-squares was applied for multivariate calibration over optimized sp ectral ranges. The mean-square prediction errors for the population of 126 plasma samples of different patients calculated by cross-validati on are in the range of clinical acceptance. Within an error variance a nalysis, the contributions of the reference method and the spectrometr ic measurement to the average (root mean square) prediction error have been estimated for each substrate, giving evidence of the limitations of the spectrometric method. The problem of the biocompatibility of t he plasma has been investigated, and the protein adsorption onto the A TR crystal can be reduced to a constant and tolerable level by appropr iate cleaning and rinsing. The potential for further improvement is di scussed.