Age-related changes in FTIR and Raman spectra of human blood

Abstract

Blood analysis by spectroscopic techniques can provide important information about biochemistry and life processes in it. Blood indices are highly variable, and plenty of factors influence them. The present work describes the combination of two methods - IR and Raman spectroscopies of blood applied to investigate gerontology issues. We carried out a pilot study of 74 blood samples. The donors were differentiated by age with the Partial Least Squares (PLS) analysis of Raman and IR spectra. Analyzing the principal component spectra obtained during PLS processn the most illustrative bands were found in the intervals 2860-3030 cm−1, 1370-1620 cm−1, 1020-1220 cm−1 and in 1650-1530 cm−1, 1380-1360 cm−1, 1220-1200 cm−1, 1002-1004 cm−1, 760-750 cm−1 in IR and Raman spectral regions, respectively. Calibration models obtained via the PLS analysis of blood vibrational spectra provide the accuracy of age determination around ±15 years from FTIR data and around ±20 years from Raman data. Though such calibrations cannot be used for the precise determination of age, the agerelated changes of blood do really exist and can be detected from vibrational spectra.