Capacity gradient anion chromatography with a borate complex as eluent.

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Borate compounds form complexes with vicinal diols, impacting anion-exchange resin capacity.
• Hydroxyl groups on resins can interact with borate eluents, reducing effective ion-exchange capacity.
• Eluent pH influences borate complex dissociation and anion elution.

Purpose of the Study:

• To develop a simultaneous anion determination method using suppressed ion chromatography.
• To optimize eluent composition and gradient profiles for enhanced baseline stability.
• To apply the method for analyzing condensed phosphates in food samples.

Main Methods:

• Utilized a Tosoh IC-Anion-PW column.
• Employed a dihydroxyphenylborane-mannitol eluent system.
• Implemented a capacity gradient technique with constant borate concentration and varying mannitol levels.

Main Results:

• Achieved stable baseline chromatography by maintaining constant borate concentration.
• Successfully prevented complex formation between the eluent and resin hydroxyl groups.
• Demonstrated the method's applicability for analyzing condensed phosphates in cheese samples.

Conclusions:

• The developed capacity gradient method enables simultaneous anion determination.
• The specific eluent system and gradient strategy enhance analytical performance.
• This technique is effective for analyzing complex mixtures, such as food additives.