On-line capillary electrophoresis instrument for industrial processes

Capillary electrophoresis instrument for on-line control of industrial processes has been developed with continuous flow delivery systems for solvent and sample. The instrument consists of a three partial cell unit, the centre part for the capillary being changeable for fluorescence or UV detections and the front and rear modules with channels for solvent control. The on-line unit has fixed tunnels for dynamic replenishment of electrolyte solution at its both ends. Due to the on-line solvent delivery system constructed into the cell unit, the capillary and the platinum electrodes will be kept uncontaminated. Samples are introduced into the capillary with pressure or electrokinetically or by using a combination of both the techniques. Samples with high ionic strength will be on-line diluted with an electrolyte solution before they are introduced into high-speed CE analyses. Voltages up to 2.5 kV can be used in separations. This presentation demonstrates the work done on the instrumentation and the advantages of dynamic sample and electrolyte feeding. Effect of flow conditions on pressure differences between capillary ends were studied by determining the electroosmotic flows with different electerolyte feeding rates and by comparing migration times and peaks shapes of separated sample peaks from the electropherogram. Electrophoretic separations with laser induced flurescence detection (LIF) are demonstrated by using CAPS as background electrolyte for the analytes fluorescein, mandelic acid and phenyl acetic acid. Preliminary results for the samples oxalate, acetate and sulphate anion, detected by the UV detector at 254 nm wavelength were also performed by using OFM-PDC as a backround electrolyte. On-line applications on pulp and paper process are demonstrated.