Abstract: Disclosed is a method and apparatus by which a sample can be taken from a process and be analyzed on-line by means of a capillary electrophoresis apparatus. On the feed side of the capillary electrophoresis unit (13) the sample is continuously collected via a duct (16) from the process into the sample feeding system and fed into the capillary ducts (2, 3) through the same duct as is the feed solution, and all the solutions (16, 17, 18, 19) both on the feed side and on the exit end of the capillary electrophoresis unit (13) are pumped through the flow ducts, and the liquids flown through the capillary are removed on the exit end of the capillary electrophoresis unit (13) by means of a liquid treatment system.

Abstract: The invention relates to a method by which a sample can be taken from a process and be analyzed by means of a capillary electrophoresis apparatus on-line, and to a capillary electrophoresis apparatus which comprises containers containing a background electrolyte solution, the containers communicating with each other by mediation of a separation capillary (1), current electrodes (E) connected to a source of voltage, and a detector (4) substantially in the vicinity of the exit end of the separation capillary (1), as well as one or more solution containers on the injection side of the apparatus, at least one of the containers being a sample collector in which the sample coming from the process is collected, and one or more solution containers on the detector side of the apparatus, the ends of the said separation capillary (1) being located in expansions (5, 6) continuing from the lower ends of capillary ducts (2, 3) intended for feeding in various solutions from the containers, the said expansions continuing as