A simple, highly selective, sensitive, and reproducible liquid chromatography-electrospray ionization/
time-of-flight mass spectrometry method has been developed for the direct and simultaneous
determination of capsaicin and dihydrocapsaicin in Capsicum fruit extracts. Capsaicin and dihydrocapsaicin
are the two major members of the so-called capsaicinoid family, which includes other minor
analogues, and usually account for at least 90% of the pungency trait in Capsicum fruits.
Chromatographic separation of capsaicin and dihydrocapsaicin was achieved with a reversed-phase
chromatography column, using a gradient of methanol and water. Quantification was done using as
an internal standard (4,5-dimethoxybenzyl)-4-methyloctamide, a synthetic capsaicin analogue not
found in nature. Analytes were base-peak resolved in less than 16 min, and limits of detection were
20 pmol for capsaicin and 4 pmol for dihydrocapsaicin. The intraday repeatability values were lower
than 0.5 and 12% for retention time and peak area, respectively, whereas the interday repeatability
values were lower than 0.6 and 14% for retention time and peak area, respectively. Analyte recoveries
found were 86 and 93% for capsaicin and dihydrocapsaicin, respectively. The method developed
has been applied to the identification and quantification of capsaicin and dihydrocapsaicin in fruit
extracts from different Capsicum genotypes, and concentrations found ranged from 2 to 6639 mg
kg-1.