Capillary electrophoresis of longer-chain polyphosphates

Capillary electrophoretic separations of sodium polyphasphates with anion chain lengths from 1 to >30 are presented. A buffer containing pyromellitic acid, triethanolamine and hexamethonium hydroxide gives a high resolution separation of linear and cyclic polyphosphate species. Distinct separation patterns can be obtained in 20 min for glassy sodium phosphates with number-average chain lengths from 5 to 44. The preliminary electrophoretic separations presented here should be useful for the rapid characterization of complex polyphosphate mixtures.