Laser ablation construction of on-column reagent addition devices for capillary electrophoresis
A simple and reproducible technique for constructing perfectly aligned gaps in fused-silica capillaries has been developed for postcolumn reagent addition with capillary electrophoresis. This technique uses laser ablation with the second harmonic of a Nd:YAG laser (532 nm) at 13.5 mJ/pulse and a repetition rate of 15 Hz to create these gaps. A capillary is glued to a microscope slide and positioned at the focal point of a cylindrical lens using the focused beam from a laser pointer as a reference. Gaps of 14.0 ± 2.2 μm (n = 33) at the bore of the capillary are produced with a success rate of 94% by ablation with 400 pulses. This simple method of gap construction requires no micromanipulation under a microscope, hydrofluoric acid etching, or use of column fittings. These structures have been used for reagent addition for postcolumn derivatization with laser-induced fluorescence detection and have been tested for the separation of proteins and amino acids. Detection limits of 6 × 10-7 and 1 × 10-8 M have been obtained for glycine and tranferrin, respectively. Separation efficiencies obtained using these gap reactors range from 38 000 to 213 000 theoretical plates.
Publication Source (Journal or Book title)
Rezenom, Y., Lancaster, J., Pittman, J., & Gilman, S. (2002). Laser ablation construction of on-column reagent addition devices for capillary electrophoresis. Analytical Chemistry, 74 (7), 1572-1577. https://doi.org/10.1021/ac015693w