title: Structural screening by multiple reaction monitoring as a new approach for tandem mass spectrometry: presented for the determination of pyrrolizidine alkaloids in plants.
abstract: In tandem mass spectrometry the multiple reaction monitoring (MRM) mode is normally used for targeted analysis but this mode also has the potential to screen for structural similarities of analytes. On the basis of the fact that in general similar molecular structures result in similar fragments or losses of neutrals, this approach was used for pyrrolizidine alkaloid (PA) screening but could also be easily adapted to screen for other compound classes. PA are plant toxins of which several hundred individual compounds have been identified. Our MRM screening approach uses the structural relation and similar core structure of all PA which results in a common and thus predictable mass spectrometric fragmentation behaviour. On this basis a method was developed which screens for PA structures by MRM transitions and allows the detection of each individual PA down to a low microgram per kilogram concentration range. The approach was applied to investigate plants from the families of Asteraceae (several species of Senecio and Eupatorium), Boraginaceae (Echium, Cynoglossum, Borago and Anchusa officinalis as well as Heliotropium europaeum) and Fabaceae (Crotalaria incana) for a complete qualitative and quantitative PA characterisation. All analytes that were detected as possible PA by MRM screening were further investigated by recording product ion spectra. Analytes which exhibited a typical PA fragmentation pattern were either confirmed as PA or otherwise deleted as false positive signals (false positive rate was below 10 %). Sum formulas of confirmed PA were determined by additional measurements applying high resolution mass spectrometry. In that way 121 unknown PA were identified and for the first time complete PA profiles of different PA plants were delivered.
authors.affiliation: Federal Institute for Risk Assessment, Department Safety in the Food Chain, Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany, anja.these@bfr.bund.de.
authors.forename: Anja
authors.initials: A
authors.lastname: These
authors.forename: Dorina
authors.initials: D
authors.lastname: Bodi
authors.forename: Stefan
authors.initials: S
authors.lastname: Ronczka
authors.forename: Monika
authors.initials: M
authors.lastname: Lahrssen-Wiederholt
authors.forename: Angelika
authors.initials: A
authors.lastname: Preiss-Weigert
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D028082:Boraginaceae / Q000737:chemistry*; D007887:Fabaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry*; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014118:Toxins, Biological / Q000737:chemistry
chemical_list: D010936:Plant Extracts; D011763:Pyrrolizidine Alkaloids; D014118:Toxins, Biological