The magnitude and reproducibility of the electroosmotic flow in silica capillary tubes

The influence of a no. of factors, such as the nature of the buffer, the presence of additives therein, the manufg. conditions, and the pretreatment of the capillary, on the magnitude of repeatability of the electroosmotic flow (EOF) in silica capillary tubes has been investigated. It was established that the nature of the buffer plays the most significant role in respect of the stability and magnitude of EOF, whereas the conditions used for manuf. and pretreatment of the tubing are less important. The EOF obtained using buffers consisting of tris(hydroxymethyl)aminomethane and ethylenediamine was more repeatable than that obtained using pure phosphate buffers. Buffer additives such as sodium dodecylsulfate, 1-butanol, sodium salts of 1-pentanesulfonic acid and 1-heptanesulfonic acid, altered the magnitude of the EOF only, not its repeatability