RAPID MICRO METHODS FOR THE GLC-DETERMINA TION OF FAT-CONTENT AND FATTY-ACID COMPOSITION IN SEEDS RICH IN LIPIDS

Rapid micro methods for the GLC determination of fat content and fatty acid composition in seeds rich in lipids, Two methods for the rapid s ample preparation for determination of fat (gravimetrically resp, by G LC) and fatty acid pattern (by GLC) in seeds with high lipid contents are presented and discussed. The adequate amount of the sample is no m ore than 50 mg for both methods. The first method requires several sub sequent steps: grinding with Na2SO4 and petroleum benzine, fat determi nation by weighing, transmethylation by sodium methylate in methanol ( time required: approx. 60 min.). The second method is an one-step meth od: grinding with Na2SO4, extraction with petroleum benzine and transm ethylation by methanol and tetramethylguanidine at the same time (time required: approx. 15 min.) - the fat content is determined by convert ing data of the fatty acid GLC results into data of triglycerides. The analytical results for different samples are compared with those obta ined by a classical reference method. In most cases the results are co mparable.