Glycolipid procedures, analysis

Other useful analytical HPLC procedures for the analysis of derivatized glycolipids have been developed. Nanaka and Kishimoto... 

Conventional electron impact or chemical ionization mass spectrometry requires that volatilization precede ionization and this is clearly a limiting factor in the analysis of many biochemically significant compounds. A newer ionization technique, field desorption (FD) (1, 2 ) removes this requirement and makes it possible to obtain mass spectrometric information on thermally unstable or non-volatile organic compounds such as glycoconjugates and salts. This development is particularly significant for those concerned with the analysis of glycolipids and we have therefore explored the suitability of field desorption mass spectrometry (FDMS) for this class of compounds. We have evaluated experimental procedures in order to enhance the efficiency of the ionization process and to maximize the information content of spectra obtained by this technique. 

The complexity of natural lipid extracts is such that it is rarely possible to claim that all the lipid classes of a sample can be separated in one operation. It is, therefore, often worthwhile to be able to isolate distinct simple lipid, phospholipid or glycolipid fractions for further analysis. For example, it is frequently easier technically to isolate small amounts of pure lipid classes preparatively by means of HPLC (or other methods), after a preliminary fractionation has been carried out. Unfortunately, no procedure appears yet to have been described that is satisfactory in all respects, although some useful methods are available provided that their limitations are recognised. 

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