Abstract
Application of programmed temperature gas chromatography (GC) has been reported for fatty acids etc., but has not been used routinely in the determination of food additives.
A Shimadzu Model GC-1C gas chromatograph, equipped with a flame ionization detector and temperature-programming apparatus, was used in our investigation. Simultaneous gas chromatographic determination was tried on six synthetic preservatives. However, accurate quantitative determination of sorbic acid, dehydroacetic acid and benzoic acid cannot be expected because the retention times of the peaks of these preservatives were so early that these peaks showing might be masked in the peak of the solvent.
Thus simultaneous determination of preservatives both early and late retention times was possible only by use of the programmed temperature GC with FID.
It was known that the application of programmed temperature was not always followed with accurate results, because both values of the relative peak area and the relative factors were affected by the different programmed gradients of temperature as compared with the case of isothermal operation.
However, the values obtained by programmed temperature operation must not be theoretically different from those determined under isothermal conditions.
As the results, the calibration curves, obtained by peak area ratio of each preservative to internal standard, show linearity within a range from 10 to 70μg for SoA and from 2 to 8μg for the others.
