A capillary coated with a metal-organic framework for the capillary electrochromatographic determination of cephalosporins

The authors have developed a rapid and reliable method for the capillary electrochromatographic determination of cephalosporin antibiotics in environmental waters. An open-tubular capillary column was modified with the complex [Cu(mal)(bpy)], a copper(II) complex with malic acid and 4,4′-bipyridyl, by an amide coupling method to act as the stationary phase. The simultaneous determination of the cephalosporins formulations, namely cefapirin (CP), ceftiofur (EFT) and cefixime (CFM) in environmental water samples was accomplished in buffer of pH 5.0 by applying a voltage of 8 kV and with DAD detection. Detection limits typically are 0.1 μg?mL^?1.The method was applied to the analysis of cephalosporins in spiked water samples from Kunming Lake to give recoveries betwen 88 and 106%.

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Graphical abstract A metal-organic framework (MOF) was synthesized from copper(II), malic acid and 4,4′-bipyridyl and used as stationary phase of capillary electrochromatography (CEC) by covalent immobilization on the capillary inner walls. Compared to an uncoated fused-silica capillary, improved separation of cephalosporin antibiotics can be accomplished.