Direct Analysis in Real Time (DART®) Ionization as a Tool for Rapid Screening and Characterization of Black Cohosh (Actaea racemosa) by MS Fingerprints
Characterization of herbal dietary supplements has increasingly become a focus for regulatory bodies. In this study we have used a Direct Analysis in Real Time (DART) ambient ionization mass spectrometry method to characterize the major ionizable components in Black Cohosh (Actaea racemosa). Analysis of both the raw natural product and several commercial products labeled as containing Black Cohosh yielded wide variation in the mass spectral composition across the products. In order to permit more uniform sampling we choose to investigate quick extraction protocols with 0.1N acid, 0.1N base, and a published method for Black Cohosh sample prep . The DART-MS experiment involves employing a thermal profile method for each extract using different gas temperatures (150 °C, 250 °C, and 350 °C) for desorption ionization and positive/negative ion mass spectrometric detection. Ferulic acid and caffeic acid desorption were optimized at 250 °C in the negative ion mode. Carbohydrates were detected at 150 °C and 250 °C in the positive ion spectra from the raw plant materials; however, they were not detected in all commercial products. The 250 °C positive and negative ion spectra proved to yield a large number of ions and these spectra were designated as the MS Fingerprint data. These MS Fingerprints were subsequently subjected to analysis using a statistical spectral matching program for automated chemometric analysis of the samples for differentiation. References:  Jiang B, Ma C, et al. (2011) Phytochem Analy, 22: 339 – 351.