title: Combination of dynamic pH junction with capillary electrophoresis-mass spectrometry for the determination of systemins in plant samples.
abstract: Systemin is an important group of plant peptide hormones participating in the regulation of plant defensive responses. An improved method, based on dynamic pH junction and capillary electrophoresis-quadrupole time-of-flight mass spectrometry, was developed for online enrichment and sensitive determination of trace systemins in plants. After optimization, the online enrichment factors for six target systemins ranged from 90- to 127-fold. The detection limits reached lower than 0.5 nM, which were comparable with the sensitivity of LC-MS method. Satisfactory quantitative results were obtained in terms of linearity (R(2) ≥ 0.993), dynamic range (3-120 ng/mL), and reproducibility (≤6.7%). For the analysis of real plant samples, a rapid sample preparation method was developed, using two steps of SPE purification with different retention and separation mechanisms. Finally, this method realized the successful detection of tomato systemin and tobacco hydroxyproline-rich systemin I from plant leaves with shorter analysis time.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, P. R. China; Analytical & Characterization, Experiment Management Center, National Institute of Clean-and-Low-Carbon Energy (NICE), Beijing, P. R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Cuilan
authors.initials: C
authors.lastname: Chang
authors.forename: Fuyou
authors.initials: F
authors.lastname: Du
authors.forename: Zhijing
authors.initials: Z
authors.lastname: Tan
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D016014:Linear Models; D018551:Solanum lycopersicum / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D010455:Peptides / Q000032:analysis*; D010940:Plant Proteins / Q000032:analysis*; D015203:Reproducibility of Results; D014026:Nicotiana / Q000737:chemistry*
chemical_list: D010455:Peptides; D010940:Plant Proteins; C073704:systemin
keywords: Capillary electrophoresis; Dynamic pH junction; Phytohormone; Quadrupole time-of-flight mass spectrometry; Systemin