A colorimetric method for the determination of glycerides

The quantitative determination of lipids is a universal and repeating problem of analytical chemistry in different fields, for example food- or biochemistry. Important criterions to value methods are the time needed for analysis, reproducibility and detection limit. The determination of glycerides can be performed by classical methods, for instance by the Weibull-Stoldt method [1] or by extraction. HPLC and GLC can be used successfully, too. All these methods are expensive of time or equipment. In this paper a colorimetric method is reported characterized by good reproducibility, great sensitivity and little time needed to perform. The determination, first time reported by Fletcher [2] is based on the oxidation of glycerol after saponification of the lipid with periodate. The formaldehyde produced is determined by coupling a dye in a Hantzsch condensation with ammonium ions and 2,4-pentadione. The 3,5-diacetyl-1,4-dihydrolutidin formed is measured in a photometer at 410 nm.