Rapid Determination of Capsaicin and Dihydrocapsaicin in Fermented Pepper Paste by Direct Analysis in Real Time Mass Spectrometry

A fast analytical method by direct analysis in real time ionization coupled to mass spectrometer (DART-MS/MS) has been developed for the estimate the capsaicin (CAP) and dihydrocapsaicin (DHCP) concentration in fermented pepper paste. Firstly, these mass fragmentation schemes of CAP and DHCP by DART-MS/MS are proposed, and compared with those of electrospray ionization source (ESI). After conducting a series of optimizations, the samples were extracted by a simple procedure using acetonitrile, the samples extracts were then directly evaluated by DART-MS/MS without chromatographic separation. A limit of detection (LOD) of 0.0234 and 0.0510 μg/mL was achieved for CAP and DHCP, respectively. The results obtained with the newly developed DART-MS/MS method are in good agreement with those by the conventional ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry method. The results showed that DART-MS/MS is a high-throughput tool for determination of CAP and DHCP concentration in food products.