Influence of capillary dimensions on the performance of a coaxial capillary electrophoresis-electrospray mass spectrometry interface

The dimensions of the capillaries used to construct a typical coaxial capillary electrophoresis-mass spectrometry (CE-MS) interface, i.e. the inner diameter, the outer diameter and the wall thickness, have been shown to affect the performance of the CE-MS system. The influence of these parameters has been investigated in both MS and MS-MS modes. The initial results indicate that by reducing all the sheath capillaries' dimensions and the CE capillary outer diameter, better operation and increased sensitivity can be achieved. The capillary arrangement which gives optimum sensitivity and stable operation has been suggested.