PROCESS AND DEVICE OF MOLECULAR SPECTROSCOPY PARTICULARLY FOR DETERMINING METABOLITES

摘要

The infrared absorption is measured in a sample (2) containing the substance sought. We determine at the same time the absorption for two different wavelengths ((Alpha) 1, (Alpha) 2) by choosing the first wavelength ((Alpha) 1) in such a way that if the concentration of the substance sought varies in the sample (2) there is a zero or negligible absorption variation while the second wavelength ((Alpha) 2) is located in an absorption band of the substance. After measurements of radiation intensities (I1 and I2) at the two wavelengths, the signal is normed by the quotient (I2 / I1). The method allows a reproducible quantitative measurement in a natural biological medium or in dialysates without pretreatment of the sample and with small quantities of substances. By choosing the second wavelength one can search for several substances.