title: Analysis of buserelin in urine by online combination of capillary zone electrophoresis with electrospray mass spectrometry.
abstract: A fast and precise analysis of the synthetic peptide buserelin in urine using CZE-ESI-MS method has been demonstrated. Formic acid at 50 mmol/L concentration served as background electrolyte in CZE stage and it is compatible with MS detection in positive ionization mode. Two injection modes were tested, i.e. pressure (50 mbar for 5 s) and electrokinetic injection (5 kV for 5 s), of which electrokinetic injection provided better calibration parameters. Buserelin LODs were 0.47 microg/mL in water and 0.63 microg/mL in ten times diluted urine samples using pressure injection, while they were 0.32 microg/mL in water and 0.34 microg/mL in ten times diluted urine samples using electrokinetic injection. Repeatability of buserelin migration times was below 6% (pressure injection mode) and 1% (electrokinetic injection mode). Repeatability of buserelin peak area in SIM mode (m/z=620.5+/-0.5) was less than 12% (pressure injection mode) and 5.8% (electrokinetic injection mode). In this work, no interferences were observed during the analyses of spiked urine samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
authors.forename: Andrea
authors.initials: A
authors.lastname: Staňová
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Marák
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Palacký University, Olomouc, Czech Republic.
authors.forename: Vítězslav
authors.initials: V
authors.lastname: Maier
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Palacký University, Olomouc, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Ranc
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Palacký University, Olomouc, Czech Republic.
authors.forename: Joanna
authors.initials: J
authors.lastname: Znaleziona
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Palacký University, Olomouc, Czech Republic.
authors.forename: Juraj
authors.initials: J
authors.lastname: Ševčík
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
authors.forename: Dušan
authors.initials: D
authors.lastname: Kaniansky
mesh_terms: D002064:Buserelin / Q000652:urine*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013696:Temperature
chemical_list: D002064:Buserelin