title: On-line preconcentration and quantitative analysis of peptide hormone of brain and intestine using on-column transient isotachophoresis coupled with capillary electrophoresis/electrospray ionization mass spectrometry.
abstract: A new approach was described to achieve very sensitive analysis of peptide hormone of brain and intestine by capillary electrophoresis coupled with a transient isotachophoresis (tITP) preconcentration method. The system used was electrospray ionization mass spectrometry (ESI-MS) as detector and equipped with a sheath flow configuration. The effects of sample matrix, pH and concentration of leading electrolyte (LE), sample injection time, and ESI-MS instrumental parameters on the efficiency of the sample stacking were investigated in detail. Under the optimized conditions, lower than micromole (0.01 microM) concentrations of the peptides were easily detected. Compared to traditional hydrodynamic injection methods, about 40-230-fold increase in detection sensitivity was obtained by this technique. A distinguishing feature of the described approach is that the background electrolyte can serve as terminating electrolyte (TE), which simplifies the process of the experiments. The method was further evaluated by the analysis of low concentration active peptide mixtures spiked in hypothalamus tissue of the rat.
authors.affiliation: Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
authors.forename: Shifei
authors.initials: S
authors.lastname: Xia
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Qiu
authors.forename: Minghua
authors.initials: M
authors.lastname: Lu
authors.forename: Yuwu
authors.initials: Y
authors.lastname: Chi
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D004573:Electrolytes; D004586:Electrophoresis; D019075:Electrophoresis, Capillary; D006863:Hydrogen-Ion Concentration; D007031:Hypothalamus / Q000737:chemistry*; D007422:Intestines / Q000737:chemistry*; D008297:Male; D036361:Peptide Hormones / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004573:Electrolytes; D036361:Peptide Hormones