Quantitation of glucose and urea in whole blood by mid-infrared spectroscopy of dry films

This paper reports the results of a study to determine whether mid-infrared (IR) spectroscopy might form the basis for quantitation of glucose and urea levels in whole blood. Spectra were acquired by first diluting whole blood specimens with a dilute potassium thiocyanate solution, drying small aliquots to dry films on BaF2 substrates and acquiring transmission spectra for the dry films. Reference analyses for urea and glucose were carried out, and partial least-squares calibrations developed using two-thirds of the 200 total specimens for calibration and the remaining one-third to validate the analytical methods. A potassium thiocyanate absorption at 2060 cm(-1) provided the means to normalize the spectra, factoring out any minor variations in film thickness. (C) 2002 Elsevier Science B.V. All rights reserved.