How to create a calibration curve when no chemically-matching reference materials with narrow molar mass distribution are available.
A review of alternative approaches to narrow standard calibration.
Gel permeation chromatography/size-exclusion chromatography (GPC/SEC) columns are filled with porous particles differing in particle and pore sizes. Typical particle sizes in analytical GPC/SEC range from sub-2-µm particles applied in oligomer and protein separations to approximately 20 µm for separations of ultrahigh molar mass macromolecules (1,2). While the effect of combining columns of different pore sizes has previously been discussed in GPC/SEC Tips & Tricks (3,4), the effect of combining columns of different particle sizes has not been addressed before.
While gel permeation chromatography/size-exclusion chromatography (GPC/SEC) of uncharged molecules in organic eluents in most cases is a straightforward task, aqueous GPC/SEC of polyelectrolytes usually requires more parameters to be considered and optimized. This instalment of Tips & Tricks explains more.