Nonaqueous Capillary Zone Electrophoresis for Polyesters and Polyamides Using Hexafluoroisopropyl Alcohol as Electrophoretic Medium

Abstract

Nonaqueous capillary zone electrophoresis (NACZE) utilizing cationic reagents as an electrophoresis promoter has the potential for separating water-insoluble synthetic polymers and that with tetrahydrofuran based electrophoretic media containing cationic reagents has been reported. In this study, NACZE using hexafluoroisopropanol (HFIP)-based media was developed for separating polyesters and polyamides, which were insoluble in tetrahydrofuran. Nonaqueous media of HFIP containing 400 mM cetyltrimethylammonium chloride (CTAC) and 50 mM trihexyl(tetradecyl)phosphonium chloride (P66614Cl) were used, and it was found that hydrophobic P66614 cation enhanced the electrophoresis of both polyesters and polyamides compared with cetyltrimethylammonium cation. The media containing CTAC resulted in partially separated poly(ethylene terephthalate)/poly(hexamethylene terephthalate) and poly(ethylene terephthalate)/poly(ethylene naphthalate), but P66614Cl failed to separate them. By contrast, nylon 6I and nylon 6/6I were separated with the P66614Cl media, whereas they were co-eluted in the media with CTAC.

Development of Novel Analytical Methods Based on Liquid Chromatography and Electrophoresis

“…To solve this problem, we developed NACZE using 1,1,1,3,3,3-hexafluoro-2-propanol (hexafluoroisopropanol, HFIP) as an electrophoretic medium [58]. In the HFIP media containing CTAC, poly(ethylene terephthalate) / poly(hexamethylene terephthalate) and poly(ethylene terephthalate) / poly(ethylene naphthalate) were partially separated, but not by P66614Cl.…”