Identification of quaternary ammonium and tertiary sulfonium compounds by plasma desorption mass spectrometry

Abstract

A rapid and sensitive method for the identification of quaternary ammonium and tertiary sulfonium compounds is described. The method utilizes plasma desorption mass spectrometry (PDMS) in which a "' Cf ionizing source produces fission fragments which interact with the sample to yield ions which are then analyzed by a time-of-flight mass spectrometer. The method was applied to analyses of authentic standards and to the identification of quaternary ammonium and tertiary sulfonium compounds in higher plant leaf extracts purifed by ion-exchange chromatography. Plant species from 14 different families were tested, including species which are known glycinebetaine, /?-alaninebetaine, prolinebetaine or /?-dimethylsulfoniopropionate accumulators. PDMS results confirmed and extended the known taxonomic distributions of these compounds. Glycinebetaine was found in one species Krameriu parvifolia from a family (Krameriaceae) not previously known to accumulate this compound. Pipecolatebetaine was identified in Achillea jilipendulina (Asteraceae). The Occurrence of prolinebetaine and hydroxyprolinebetaine(s) was confirmed in three species (Lumium maculatum, Stachys byzantina and Phlom's fruticosa) of the tribe Lamieae of the subfamily Lamioideae in the family Lamiaceae, but not in a fourth member of this tribe (Physostegia virginiana). The last species accumulated only trigonelline. The PDMS method was also used to identify trigonelline-deficient Zea mays lines.

Quantitative profiling method for phytohormones and betaines in algae by liquid chromatography electrospray ionization tandem mass spectrometry

“…Further, there are still difficulties in the analysis of some plant hormones by GC because certain phytohormones are thermally unstable (Ma et al, 2008). Betaines have been analyzed by mass spectrometry with a variety of desorption-type ionization techniques including fast atom bombardment (Hanson et al, 1994), and plasma desorption (Bonham et al, 1995). However, fast atom bombardment and plasma desorption have the drawbacks of reduced sensitivity and incomplete resolution of complex mixtures of betaines.…”

Characterization of amino acid‐derived betaines by electrospray ionization tandem mass spectrometry

“…Because of the permanent positive charge on the quaternary ammonium moiety, mass spectrometric analysis has been approached by desorption methods such as fast atom bombardment (FAB), desorption chemical ionization and plasma desorption (PD) mass spectrometry. [12][13][14][15][16] The positive ion desorption chemical ionization mass spectra of the betaines were dominated with protonated molecule ions including a few fragment ions resulting from thermal loss of one of the quaternary methyl groups, [12] but it had drawbacks of reduced sensitivity and incomplete resolution of complex mixtures of betaines. The FAB and PD-MS were successfully applied to analyze the betaines where the major ions observed were protonated and cluster ions.…”

“…The FAB and PD-MS were successfully applied to analyze the betaines where the major ions observed were protonated and cluster ions. [13,14] The FAB-MS sensitivity increased when the samples were derivatized to their n-propyl or n-butyl esters prior to analysis, [15] and the spectra included fragment ions typically associated with the loss of the alcohol group. But such derivatization steps can be time-consuming and may lead to poor recoveries.…”

Development and characterization of near‐isogenic lines of sorghum segregating for glycinebetaine accumulation

“…The aqueous phase was removed, air‐dried and dissolved in distilled water. Betaines were purified by ion exchange chromatography as described previously (Bonham et al 1995). Betaines were eluted from Dowex‐50‐H + with 6 ml 6 M NH 4 OH, air‐dried and quantified as described in the following section.…”