We report a new technique of absorption measurement for capillary super-thin cell in the first time. The new technique determines the absorbed intensity instead of the absorbance as conventionaly was. The absorbed intensity is measured for a capillary cell (i. d. 50μm) and a decussate optical super-thin cell (40μm) for serial KMnO~4 solutions. High sensitivity and good S/N ratio are observed, and the calibration curves are fairy linear. For a 10μg/mL KMnO~4 solution, the S/N ratio of absorbed intensity determination is about 10, which is better than that of absorbance determination in the capillary cell. This super-thin cell in the decussate configuration provides a novel type optical detection cell for capillary electrophoresis.

Key words: CAPILLARY ZONE ELECTROPHORESIS, ULTRAVIOLET SPECTROPHOTOMETRY