Organic Acid Analysis
ICSep Columns for Organic Acid Analysis
Ion exclusion is the preferred method for the separation of weakly ionizable species such as organic acids and alcohols. Transgenomic provides a broad range of columns that provide varying efficiencies and selectivities for the separation of weak acids by ion exclusion.
The packings employed with ion exclusion are totally sulfonated polystyrene divinylbenze (PS/DVB) copolymers. By totally sulfonating the polymer, the bead behaves as though it were a negatively charged sphere. This charged sphere is referred to as a Donnan membrane. Species that have a negative charge are repelled from the negatively charged membrane, while uncharged species are allowed to enter the sphere and adsorb onto the beads.The mobile phases employed with ion exclusion are low concentration acids, such as 5mM sulfuric acid.
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R-COO- + H+ <——> R-COOH
(repelled) (retained) |
This equilibrium is regulated by the acidic dissociation constant (pKa) of the organic acid or alcohol. Therefore, species are analyzed by ion exclusion and elute according to their pKa.
Features
The key features of the ICSep ion exclusion columns are:
- Polymeric Substrate
- High efficiency
- High resolution
- Separates organic acids, carbohydrates, and alcohols on the same column
- Very Rugged Design which provides long life
Since ICSep columns are based on a polymeric substrate consisting of polystyrene/divinylbenzene copolymers they are stable in the pH range of 0 to 14, temperature stable, and very rugged. The ICSep organic acid columns have been shown to last for thousands of runs without cleaning.They show very good lotto-lot and column-to-column reproducibility with retention times varying by less than 1%.
Transgenomic offers ICSep organic acid columns to meet your analytical needs. ICSep columns are available that focus on speed or efficiency and there are ICSep ion exclusion columns that focus on ruggedness and the ability to handle dirty samples.There are even ICSep columns for aromatic organic acids.Transgenomic is sure to have an ion exclusion column to meet your needs.
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