KCS

A novel nonaqueous capillary electrophoresis (NACE) method was developed for high sensitive detection of various synthetic organic dyes (i.e., crystal violet, methyl violet B, methyl violet B base, rhodamin 6G, and rhodamin B base) using a laser-induced fluorescence (LIF) detector. Elution behaviors of the dyes in a fused-silica capillary (75 μm I.D. x 365 μm O.D.) were observed in various organic solvents such as methanol, ethanol, dimethylformamide, dimethylsulfoxide, and acetonitrile. The NACE separation optimum condition was 20 mM sodium borate and 870 mM acetic acid in dimethylformamide solvent under the electric fields of 400 V/cm. The dyes were detected within 13 min with excellent baseline separations (resolution ≥2.041). The limits of detection (crystal violet, methyl violet B, methyl violet B base, rhodamin 6G, and rhodamin B base) were 3.40 x 10^-11 M, 2.94 x 10^-10 M, 4.33 x 10^-10 M, 1.11 x 10^-14 M, and 4.20 x 10^-16 M, respectively. Enhanced detection sensitivity of the NACE-LIF method should contribute to the high sensitive detection on a trace analysis and forensic science.