Comparison of LC Columns Packed with 2.6 mu m Core-Shell and Sub-2 mu m Porous Particles for Gradient Separation of Antibiotics
Abstract
The recently introduced Kinetex C18 column packed with core-shell 2.6 mu m particles is declared to provide similar efficiency and short analysis as Acquity BEH C18 column with 1.7 mu m porous particles. Unlike Acquity BEH C18 column, Kinetex C18 column exhibited lower column backpressure making this column compatible to conventional LC systems.
The performance of Kinetex C18 column (2.1 x 50 mm) and Acquity BEH C18 column (2.1 x 50 mm) for gradient separation of tetracyclines under acidic conditions (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) and macrolides under alkaline conditions (tylosin, clarithromycin, roxithromycin, and carbomycin) was studied. The columns were compared by evaluation of their experimental peak capacity and its dependence on linear velocity and gradient slope.
The maximal experimental peak capacities for analysis of tetracyclines were 51.8 (Acquity BEH C18 column) and 48.4 (Kinetex C18 column). This indicated that Kinetex C18 was a suitable alternative to Acquity BEH C18 column for the analysis of tetracyclines under acidic conditions.
On the contrary, the maximal experimental peak capacities for analysis of macrolides on Acquity BEH C18 column was higher (46.7) than that on Kinetex C18 column (36.9). Moreover, application of Kinetex C18 column for the analysis of macrolides under alkaline conditions was limited with respect to its decreasing performance with growing number of injections on the column.