How to upgrade HPLC to ion chromatography

2021-10-09 14:07:43 158

What is the difference between HPLC and ion chromatography? Is there a possibility of upgrading?


Chromatography high pressure pump


HPLC: stainless steel pump heads are mostly used, and buffer salt systems can be used.

Ion chromatography: PEEK pump heads are mostly used, and the whole system has no metal parts in contact with the eluent.

In ion chromatography analysis, the eluent used for anion analysis is usually carbonate system and hydroxide system. Although the composition is different from the buffer salt system used in HPLC, the requirements for the pump are the same. From this aspect For analysis, the HPLC pump can be used as an ion chromatography pump to analyze anions.

The eluent used in cation chromatography analysis is acid. Although the concentration is not high, it will not cause obvious damage and corrosion to the pump head, but there will be metal ions dissolved in the eluent. When the suppression method is used, the conductance will be biased. High, affect the quantitative results, so the HPLC pump is not suitable for cation analysis.


Column


Most HPLC columns are reversed-phase columns, and individual ion exchange columns are used, but the exchange capacity is not high, so HPLC and ion chromatography columns cannot be used in common, so if you want to upgrade to ion chromatography, you must purchase ion chromatography columns.

Post-column suppression and derivatization system

A derivatization system can be optionally installed after the HPLC column, and a suppressor must be installed after the ion chromatography column to improve sensitivity. The upgrade requires the purchase of a suppressor.

Mobile phase


Detector


HPLC: UV, fluorescence and other detectors

Ion chromatography: detectors such as conductivity and ampere

HPLC can be upgraded to ion chromatography by expanding the detector, and the built-in UV and fluorescence detectors can also expand the detection range of ion chromatography.


Injector


HPLC: stainless steel injection valve, can be used for anion chromatographic analysis, not suitable for cation analysis

Ion chromatography: PEEK injection valve, compatible with acid and alkali solutions

In summary, the pumps and valves of HPLC can be directly used for anion chromatography analysis, and it is necessary to purchase chromatography columns, detectors, and suppressors to expand and upgrade to ion chromatography.