Contactless Conductivity Detection in Capillary Electrophoresis Employing Capillaries with Very Low Inner Diameters
Abstract
The behaviour of a contactless conductivity detector was studied in its application to capillary electrophoresis employing quartz capillaries with inner diameters (i.d.) of 10 to 75 inn. The detector output signal was measured using KCl as the test electrolyte, within a KCl concentration range from 0 to 100 mmol/L, corresponding to specific conductivities from 0 to 1295 mS/m.
When using capillaries with high inner diameters, then the signal-to-noise ratio is high in electrolytes of low conductivity. On the other hand, the use of capillaries with low i.d. values is useful in separations employing solutions of high conductivities.
The advantages of capillaries with small i.d. values, combined with contactless conductivity detection, are demonstrated on separations of mixtures of inorganic ions and on Separations of neutral mono- and disaccharides.