retention index

chemistry

Also known as: RI

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July 13, 2026

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The term "RI" can refer to refractive index or Rhode Island. In chemistry, "RI" specifically refers to the retention index, a concept used in gas chromatography.12

Gas chromatography (GC) is a method that separates components of a mixture using a gaseous mobile phase and a stationary phase. The retention index quantifies how long a solute stays in the column relative to known compounds, aiding in identification. This is particularly useful when mass spectral data is unavailable. The retention index helps classify stationary phases based on polarity and intermolecular interactions.23

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chromatography
Gas chromatography
…logarithmic scale this becomes the retention index (RI) introduced by the Swiss chemist Ervin sz. Kováts. The RI values of the solvent probes serve as the basis for the classification method introduced by Rohrschneider. Similar schemes have been suggested for liquid systems.
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…logarithmic scale this becomes the retention index (RI) introduced by the Swiss chemist Ervin sz. Kováts. The RI values of the solvent probes serve as the basis for the classification method introduced by Rohrschneider. Similar schemes have been suggested for liquid systems.
Read More