title: Expanding the scope of pressure-assisted electrokinetic injection for online concentration of positively charged analytes in capillary electrophoresis-mass spectrometry.
abstract: Sample injection is a crucial step in CE. In past, many efforts have been focused on concentrating the analytes into a sharp sample plug. In 2006, pressure-assisted electrokinetic injection (PAEKI) was proposed as a new preconcentration technique for anions. In this study, we expanded the applicability of PAEKI to online preconcentrate positively charged analytes. L-Arginine, L-lysine, and imidazole were chosen as target analytes for method development. The enhancement factor of PAEKI was over 3000-fold. When CZE was coupled with a Q-TOF system, PAEKI delivers a detection limit of 18-28 pg/mL and a dynamic calibration range over four orders of magnitude. The RSD was less than 6.4% (n = 4) on both peak area and migration time, indicating a good repeatability.
authors.affiliation: Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Lucia
authors.initials: L
authors.lastname: D'Ulivo
authors.forename: Yong-Lai
authors.initials: YL
authors.lastname: Feng
mesh_terms: D001120:Arginine / Q000032:analysis; D002138:Calibration; D019075:Electrophoresis, Capillary / Q000379:methods*; D007093:Imidazoles / Q000032:analysis; D057230:Limit of Detection; D008239:Lysine / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods; D011312:Pressure
chemical_list: D007093:Imidazoles; C029899:imidazole; D001120:Arginine; D008239:Lysine
keywords: Capillary electrophoresis-mass spectrometry; Online preconcentration; Positively charged analytes; Pressure-assisted electrokinetic injection