Compositional analysis of natural wax ester mixtures by tandem mass spectrometry

Tandam mass spectrometry is particularly suited for the analysis of complex, natural wax ester mixtures R1‐CO2‐R2. Reduction of the mixture with deuterium provides species that are separble (through mass spectrometry) based on the number of original double bonds. Chemical ionization with isobutane produces high yields of protonated molecular ions and very little further fragmentation. These ions are separated by the first mass filter and then dissociated through collisions with argon. The positively charged dissociation products are almost exclusively the protonated acid ions (R1‐CO2 H2)+ that can then be separated by the second mass filter before detection and quantitation. The technique overcomes many of the obstacles previously faced during wax ester analysis. Results from this method are compared with those obtained by previous work, and the isomer composition of a new wax ester oil, orange roughy oil, is given. DIRECT SUPPORT A03O2445 00003