title: Capillary electrophoresis-tandem mass spectrometry combined with molecularly imprinted solid phase extraction as useful tool for the monitoring of 5-nitroimidazoles and their metabolites in urine samples.
abstract: A novel capillary electrophoresis-tandem mass spectrometry approach is proposed for the determination of eleven 5-nitroimidazoles in urine samples for therapeutical drug monitoring purposes. A comparison between two separation modes, namely micellar electrokinetic chromatography and capillary zone electrophoresis was carried out, obtaining higher selectivity when 1M formic acid (pH 1.8) was selected as background electrolyte. 5-Nitroimidazoles were hydrodynamically injected in water for 40s at 50mbar and their separation was performed at 28kV and 25°C. To improve migration time repeatability, a pressure of 50mbar was applied to the inlet vial during runs without any loss of peak resolution. Electrospray ionization parameters were established as follow: 6L/min, dry gas flow rate; 51,021.2Pa, nebulization pressure; 160°C, dry gas temperature. Sheath liquid consisted of a mixture of propan-2-ol/water/acetic acid (60.0:38.8:0.2% v/v/v) supplied at 3.3µL/min. MS parameters were optimized for analyte identification through their MS2and MS3spectra. The method was applied to the determination of 5-nitroimidazoles in urine samples, applying molecularly imprinted solid phase extraction for sample clean-up. Recoveries higher than 79.2% demonstrated the suitability of the procedure. Limits of detection ranged from 9.6 to 130.2µg/L while precision assays resulted in relative standard deviations for peak areas lower than 16.1%.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva S/N, E-18071 Granada, Spain.
authors.forename: Maykel
authors.initials: M
authors.lastname: Hernández-Mesa
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva S/N, E-18071 Granada, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Cruces-Blanco
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva S/N, E-18071 Granada, Spain. Electronic address: amgarcia@ugr.es.
authors.forename: Ana M
authors.initials: AM
authors.lastname: García-Campaña
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D009593:Nitroimidazoles / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000652:urine*; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D016482:Urinalysis / Q000379:methods*
chemical_list: D009593:Nitroimidazoles; C052587:4-nitroimidazole
keywords: 5-nitroimidazoles; Capillary electrophoresis; Mass spectrometry; Molecularly imprinted polymers; Urine samples