Rapid identification of solanesol even in the presence of a complex matrix can be accomplished using fast atom bombardment (FAB) mass spectrometry in combination with tandem mass spectrometry methods. FAB MS analysis using a nitrobenzyl alcohol matrix doped with lithium yields an abundant (M + Li)+ ion of m/z of 637 which is a very characteristic marker for the presence of solanesol and is quite sufficient for screening for the presence of solanesol in many cases. MS/MS analysis of this ion produces a spectrum which yields specific structural information regarding each isoprene unit of the entire structure. Furthermore, these methods are very useful for characterizing unknowns as demonstrated by the characterization of diol, triol and ester impurities in commercially available solanesol. Application of the MS/MS/MS analysis provides insight into the fragmentation mechanism and can be a useful alternative to conventional labeling methods for confirming spectral interpretations.