Single-Particle Fritting Technology for Capillary Electrochromatography.

Large perfusive silica beads (particle size 110 μm, throughpore ∼2 μm) held in place by the keystone effect were used as single-particle flits for the manufacture of particulate packed capillary columns. High-quality capillary electrochromatographic separations of a standard test mixture of alkylbenzenes were obtained over the full voltage range of 5-30 kV, with no requirement for pressurization. Excellent robustness was demonstrated by the reproducibility of migration times, peak efficiencies, and resolution during 100 consecutive runs at the highest voltage (30 kV) without thermostating and pressurization. Superior performance relative to traditional sinter-fritted columns is ascribed to the heat-free flitting process and short flit length of ∼110 pm. [ABSTRACT FROM AUTHOR]