Triglycerides and glycerol concentration Determinations using plasma FT-IR spectra

FT-IR spectrometry was used for plasma triglyceride and glycerol concentration measurements, based on their most characteristic IR absorbances within the 1200-800 cm(1) interval. Plasma samples from 68 sportsmen were taken at rest and after an endurance exercise that induced important lipolysis. After subtraction of glucose and lactate absorbances from exercise plasma FT-IR spectra, triglyceride concentration was accurately determined using the spectral window centered at 1106 cm(-1) (0.86 +/- 0.19 vs. 0.84 +/- 0.17 mMol/L; r = 0.97, P < 0.01; SEP = 0.14 mMol/L). Total glycerol concentration (sum or glycerol and glyceryl residue concentrations) was determined using the spectral window centered at 926 cm-1, which was round common to triglycerides and glycerol (0.306 +/- 0.057 vs. 0.326 +/- 0.051 mMol/L; r = 0.98, P < 0.01; SEP = 0.02 mMol/L). Glycerol concentration could be determined using the spectral window centered at 852 cm(-1) (0.216 +/- 0.039 vs. 0.231 +/- 0.048 mMol/L r = 0.95, P < 0.01. SEP = 0.03 mMol/L). However, weak glycerol concentration could be only indirectly determined by subtracting glyceryl residue concentration from total glycerol concentration that had been determined using the spectral window centered at 926 cm (1) (0.191 +/- 0.061 vs. 0.176 +/- 0.051 mMol/L; r = 0.90, P < 0.05; SEP = 0.02 mMol/L). Indeed, FT-IR spectrometry appears to be an accurate method for multiple biomolecular concentration determination on plasma samples.