Evaluating sodium salts as pushing agents on high-performance anion-exchange chromatography with pulsed amperometric detection for maltodextrin analysis
Journal
Starch/Staerke
Journal Volume
49
Journal Issue
12
Pages
505-511
Date Issued
1997
Author(s)
Abstract
Sodium hydroxide and sodium salts of acetate, nitrate and sulfate were chosen as pushing agents for maltodextrin analysis by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Different concentrations of sodium hydroxide solution, 100 mM to 500 mM, were used for direct detection of maltodextrins on a set of gold working and saturated calomel reference electrodes. Chromatographic capacity factors, k', of maltodextrins increased as molecular size increased. Sodium hydroxide alone was not adequate for an optimal maltodextrin separation. Sodium salts of acetate, nitrate, and sulfate were tested as pushing agents. The salts were compatible with the system, increased the separation selectivity and enhanced the detector response of PAD. The ability of pushing agents to decrease k' followed the order of sulfate > nitrate > acetate > hydroxide. After being eluted with pushing agents, the column regeneration time of CarboPac PA1 was 180, 240 and 360 min for the acetate, nitrate, and sulfate salts, respectively. An alternate process to shorten the regeneration time for maltodextrin separation was demonstrated. Sodium azide, as a preservative, did not affect the separation and quantification of the analysis. Sodium nitrate was the best pushing agent for the homologous maltodextrin separation.
Type
journal article