Polymer analysis by supercritical fluid chromatography.

Synthetic polymers always have distributions of the degrees of polymerization. Supercritical fluid chromatography (SFC) is almost only one technique to be able to separate pure polymer that has exactly unique degree of polymerization. For typical examples of SFC separation of polymers, four kinds of polymers: polystyrene, poly(ethylene glycol), some nonionic surfactants, and polyprenol are described about the conditions of SFC. Separated pure polymers which have no molecular weight distribution, are called uniform polymer. Uniform polymers are really useful to calibrate or validate various detectors. Here, the applications of calibrating ultraviolet detector, evaporative light scattering detector, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry are summarized. These detectors have strong molecular weight dependence of their sensitivity coefficient, in contrast to the good linearity of sample concentration.