We demonstrate channel wall coating using a cellulose derivative on a poly-(methyl methacrylate) (PMMA) CE microchip to eliminate EOF disturbing protein separation. The channel walls were modified by preconditioning with a solution containing the cellulose derivative and then thermally evaporating the solution to produce hydrophilic channel walls which prevent adsorption of analytes via a hydrophobic interaction. When the PMMA substrate was coated with the cellulose derivative hydroxypropylmethylcellulose (HPMC) 90SH, the water contact angle on the coated substrate was decreased (up to 15°) and EOF was significantly suppressed (up to 4.0 × 10-6 cm2·V-1·s-1). Three proteins (20.5, 68.0, and 114.6 kDa) were successfidly separated on the 0.15% HPMC 90SH-coated channel walls with good reproducibility of migration time (RSD <1.75%) and high efficiency (theoretical plate number per meter: 2.62 × 105).
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Clinical Biochemistry