FIBER-OPTIC-BASED UV-VISIBLE ABSORBENCY DETECTOR FOR CAPILLARY-ELECTROPHORESIS, UTILIZING FOCUSING OPTICAL-ELEMENTS

A compact and flexible fiber-optic cell for absorbance detection in ca pillary electrophoresis (CE) has been developed. Optical fibers with a large core diameter were combined with focusing optics and a circular aperture, the size of the aperture being matched to the I.D. and O.D. of the separation column, in order to maximize light throughput and r educe stray light. The detection limit for mesityl oxide was 1.5 mu M for a 100-mu m I.D. column, and the linear dynamic range was larger th an 1000 for columns from 100-mu m I.D. down to 30-mu m I.D. The design is suitable for high-speed CE, utilizing short columns. (C) 1998 Else vier Science B.V. All rights reserved.