Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.

摘要: Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids tissue poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment carried out by electrospraying micro-droplets solvent onto native or freshly-cut plant surfaces. No sample preparation required spectra are recorded under ambient conditions, times a few seconds. impact sprayed droplets on surface produces gaseous ions from organic compounds originally present tissue. effects operating parameters, including high voltage, heated capillary temperature, infusion rate carrier gas pressure analytical performance evaluated optimized. Different types material analyzed seeds, stems, leaves, roots flowers. All previously reported have been detected C. maculatum, while fifteen nineteen known for D. stramonium principal A. belladonna were also identified. identifications confirmed tandem spectrometry. Results obtained show similar spectra, number alkaloids, signal intensities those when extraction separation processes performed prior spectrometric analysis. Evidence provided that DESI occurs both gas-phase process droplet pick-up mechanism. Quantitative precision compared with conventional (after workup) RSD values same set 25 dicotyledonous maculatum seeds (one half each seed ESI other DESI) 9.8% 5.2%, respectively.