On-line multichannel Raman spectroscopic detection system for capillary zone electrophoresis

An on-line multichannel Raman spectroscopic detection system for capillary zone electrophoresis using a charge-coupled device as the detector is described. Resonant, near-resonant and non-resonant excitation Raman spectroscopies are employed. The 400 cm-1 spectral window provides adequate information to identify resolved and unresolved compounds. The use of analyte velocity reduction to allow increased data acquisition times is described. With near-resonant enhancement, the technique is shown to allow detection of 500 attomoles of methyl orange from a 5-nl injection volume, corresponding to 1 x 10(-7) M.