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Simultaneous separation of nitrofuran antibiotics and their metabolites by using micellar electrokinetic capillary chromatography
Author(s) -
Wickramanayake Priyanga U.,
Tran Tin C.,
Hughes Jeff G.,
Macka Mirek,
Simpson Nigel,
Marriott Philip J.
Publication year - 2006
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200600105
Subject(s) - chromatography , chemistry , micellar electrokinetic chromatography , elution , extraction (chemistry) , capillary electrophoresis , resolution (logic) , analyte , nitrofuran , solvent , reproducibility , artificial intelligence , genetics , organic chemistry , biology , computer science
Abstract Mixtures comprising nitrofuran antibiotics (NFA) and nitrofuran metabolites (NFM) were resolved for the first time by using MEKC. Sodium deoxycholate (SDC) was chosen as the micelle‐forming surfactant. Optimization of separation conditions was achieved by using a central composite experimental design (CCD) approach. Experimental parameters such as concentration ratio of borate to phosphate in the buffer, pH of the running electrolyte and voltage were investigated. The effect of concentration of the surfactant on resolution was significant. Under optimal conditions of 80 mM SDC, pH 9.0, (20 mM borate + 20 mM phosphate) and 16 kV, the resolution between eight consecutive peak pairs ranged from 1.9 to 11.8. Due to the absence of a UV‐active chromophore in the metabolites, they were derivatized with 2‐nitrobenzaldehyde (2‐NBA). In order to mimic a proposed extraction procedure for the analysis of both NFA and/or derivatized NFM in a sample, aqueous samples (prederivatized with 2‐NBA) were extracted by using C 18 SPE cartridges. After washing with H 2 O, the cartridges were eluted with a small portion of organic solvent with weak elution characteristics to remove excess 2‐NBA (hexane was chosen). Target analytes were then recovered with ACN. Excellent reproducibility of migration time ( t mig ) was achieved for all analytes using the developed MECC approach, with absolute t mig <1% RSD and t mig ratio <0.2% RSD, and peak area ratio was 4% RSD. The LOD for each compound, calculated by extrapolating to an S/N of 3, were found to be 0.19–2.0 μg/mL.