title: Development of an ultrasensitive stacking technique for 5-nitroimidazole determination in untreated biological fluids by micellar electrokinetic chromatography.
abstract: Cation-selective exhaustive injection and sweeping followed by a MEKC separation is evaluated for the sensitive analysis of 5-nitroimidazoles in untreated human serum and urine. Deproteinized serum and urine samples were diluted 76 and 143 times, respectively, in a low-conductivity solvent (5.00 mM orthophosphoric acid containing 5.0% v/v methanol). Samples were electrokinetically injected at 9.8 kV for 632 s in a previously conditioned fused-silica capillary (65.0 cm × 50 μm id). Separation was performed at -30 kV and 20°C using 44 mM phosphate buffer (pH 2.5), 123 mM SDS, and 8% v/v tetrahydrofurane as BGE. Signals were monitored at 276 nm and peak area was selected as analytical response. Good linearity (R(2) ≥ 0.988) and LODs lower than 1.5 and 1.8 μg/mL were achieved in serum and urine, respectively.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
authors.forename: Maykel
authors.initials: M
authors.lastname: Hernández-Mesa
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Airado-Rodríguez
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: García-Campaña
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Cruces-Blanco
mesh_terms: D002412:Cations; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D009593:Nitroimidazoles / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*; D015203:Reproducibility of Results
chemical_list: D002412:Cations; D009593:Nitroimidazoles; C052587:4-nitroimidazole
keywords: 5-Nitroimidazoles; Cation-selective exhaustive injection; Human serum; Human urine; Micellar electrokinetic chromatography