CHARACTERIZATION OF QUARTZ CAPILLARIES FOR CAPILLARY ELECTROPHORESIS

Different brands of commercially available quartz capillaries were investigated with respect to their optical and surface properties. Differences in inner diameter influence the detection sensitivity. Surface properties influence the electroosmotic flow (EOF). It is recommended to control the inner diameter and determine the EOF as a function of pH if new batches of capillaries are used. GC measurements and the dependence of retention on temperature permit one to characterize the coating procedure for non-polar coatings and to differentiate between polar and non-polar interactions. These values are in good agreement with measurements of the EOF and its dependence on pH.