The sample is analyzed by gas chromatography ,after silyating with MSTFA. Calibration is achieved by the use of two internal standards and four reference materials.Mono-,di-,and tringlyceri-des are determined by comparing to monoolein ,diolein ,and triolein standards respectively. Average conversion factors are applied to the mono-,di-,and triglycerides to calculate the bond-ed glycerin content of the sample.