On-line gas chromatographic evaluation of iodine values in edible fats and oils.

A method is reported where an on-line evaluation of gas-chromatographic data allows direct calculation of iodine values of fats and oils. Iodine values are printed out in the final analysis report of fatty acid methyl ester gas chromatographic analysis. For this purpose a simple equation was established which included double-bond increments of fatty acids, mean molecular weights and molecular weight contributions of each single component of the mixture. In a further step, a computer program was developed (Spectra-Physics 4100 Integrator) that allowed the final on-line print-out of the results. To evaluate the reliability of the method, comparative analyses by titration were carried out. No significant differences in the results could be observed.