Influence of the capillary edge on the separation efficiency in capillary electrophoresis

The results of the present work show that the physical shape of the injection end of the capillary in CE has a major effect on the observed efficiencies. Straight-edge capillaries yield much more efficient electropherograms than do slanted edge capillaries. Also, injections into straight-edge capillaries give more symmetrical peaks. Indications are that the effect of the inlet shape is independent of molecular size. Moments analysis shows that the increase in size of the injected plug. due to the slanted shape of the capillary inlet, is not sufficient to explain the large decrease in efficiency.