Background: Various techniques have been applied for detecting anacardic acid, cardanol,
cardol, and 2-methylcardol and their degrees of unsaturation in a complex mixture of a highly
corrosive cashew nut shell liquid found in the cashew (anacardium occidentale) nut shells. However,
very little has been reported on the applicability of matrix-assisted laser desorption/ionisation
time-of-flight mass spectrometry for the same. The aim of this paper is to report the application of
this technique for identifying those components in technical cashew nut shell liquid obtained by a
Methods: The cashew nut shell liquid analyte was diluted in acetone before adding a matrix of 2,5-
dihydroxybenzoic acid, which contained acetone in a volumetric ratio of 1:2. This was followed by
doping the analyte with either sodium or silver trifluoroacetate.
Results: The mass spectra obtained by both sodium trifluoroacetate and silver trifluoroacetate dopants
revealed existence of well-resolved peaks ascribed to cardanol and cardol in the analyte. It
was further observed that the peaks corresponding to 2-methyl cardol and anacardic acid in the analyte
could only be detected by using sodium trifluoroacetate dopant. The results have further revealed
the possibility of the material to contain traces of other components between 0.3 and 23%.
Peaks associated with those components may have been overlapped with peaks ascribed to the phenolic
Conclusion: The results therefore suggest that this technique may be applicable for characterising
the composition of technical cashew nut shell liquids when proper sample preparation is done and
appropriate solvents, dopants and matrices are used.