Light-scattering and turbidimetric detection of silica colloids in size-exclusion chromatography
Document Type
Article
Publication Date
1-1-2008
Abstract
Silica colloids were separated by size-exclusion chromatography and monitored by fluorimetric and UV detection. In the former means of detection, silica colloids were visualized by light-scattering. The signal intensity based on the light scattering increased with increasing size of the silica colloids. The maximum intensity was observed at excitation wavelengths around 270-290nm. In UV detection, silica colloids were visualized based on turbidimetry, and the signal intensity also increased with increasing size of the silica colloids and with decreasing detection wavelength. The signal intensities for both light-scattering and turbidimetric detection were a linear function of the concentration of the silica colloids. The detection limit at S/N=3 for 78-nm colloids was 0.06 ppm for light-scattering detection whereas the LOD was 2.3 ppm for UV detection. Effects of mobile phase conditions and flow rate on resolution and peak shape were examined. Use of phosphate buffer allowed the separation of silica colloids of different sizes in size-exclusion chromatography.
Keywords
Silica colloids, size-exclusion chromatography, fluorimetric and UV detection, signal intensity, maximum intensity, turbidimetry, mobile phase conditions, flow rate on resolution
Divisions
PHYSICS
Publication Title
Analytical and Bioanalytical Chemistry
Volume
391
Issue
1
Additional Information
Department of Physics, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA