Refractometric detector for a microcolumn high-performance size-exclusion and micro gel chromatograph

It is shown that an interference‐polarizing refractometric detector makes it possible to use microcolumn size‐exclusion chromatography (MSEC) columns with inner diameters of 0.2 to 0.5 mm and ensures a detection limit (at a signal to noise ratio of 3) of 8 × 10−8 refractive index units. Taking into account the above requirements, a micro‐gel chromatograph with a refractometric (interference‐polarizing) detector was developed. Teflon columns gave reproducibilities (the mean square deviation at the 95% confidence level) of retention times and signal amplitudes of 0.2% and 0.5%, respectively, which ensures reproducibilities of molecular weight determinations within about 2 to 4%. Examples of polymer and protein analyses carried out on this chromatograph are given. It is suggested that a micro‐gel chromatograph can be developed for fused‐silica capillary columns with inner diameters of 0.2 mm. This would permit analysis of approximately 10 pg of polymer.