Analysis of Cytokinin Nucleotides in Coconut (Cocos Nucifera L.) Water Using Capillary Zone Electrophoresis-Tandem Mass Spectrometry After Solid-Phase Extraction

J Chromatogr A. 2006 Nov 10;1133(1-2):322-31. doi: 10.1016/j.chroma.2006.08.027. Epub 2006 Sep 11.

Abstract

A method based on solid-phase extraction (SPE) and capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) is described for the separation and determination of six cytokinin nucleotides in coconut water. The best CZE separation for the six cytokinin nucleotide standards was achieved using a 25 mM ammonium formate/formic acid buffer (pH 3.8) and 2% (v/v) methanol with an applied gradient separation voltage (25 kV for 32 min, and then a linear gradient to 30 kV in 5 min, finally 30 kV to the end of separation) in less than 60 min. MS/MS with multiple reaction monitoring (MRM) detection was carried out to obtain sufficient selectivity and sensitivity for the cytokinin nucleotides. The combined use of on-line sample stacking and CZE-MS/MS achieved limits of detection (LODs) in the range of 0.06-0.19 microM for the six cytokinin nucleotides at a signal-to-noise ratio of 3. Furthermore, a novel dual-step SPE procedure was developed for the pre-concentration and purification of cytokinin nucleotides using Oasis HLB and Oasis MAX cartridges. The recoveries of the cytokinin nucleotides after the dual-step SPE were in the range of 44-71%. The combination of off-line SPE, on-line sample stacking and CZE-MS/MS approach was successfully applied to screen for endogenous cytokinin nucleotides present in coconut water sample. trans-Zeatin riboside-5'-monophosphate (ZMP) was detected and quantified in coconut water by CZE-MS/MS after SPE and on-line sample stacking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cocos / chemistry*
  • Cytokinins / analysis*
  • Cytokinins / chemistry
  • Electrophoresis, Capillary / methods*
  • Mass Spectrometry / methods*
  • Molecular Structure
  • Reproducibility of Results
  • Spectrometry, Mass, Electrospray Ionization / methods

Substances

  • Cytokinins