Ion chromatography - Glossary - peptidetesting.cc

Ion chromatography (IC) is a high-performance liquid chromatography (HPLC) method that separates and measures charged molecules within a sample. This technique uses an ion-exchange process in a charged column to identify small ions, such as salts, which is critical for verifying the composition of laboratory-produced peptides.

Ion chromatography measures residual ions to determine true peptide content

In peptide testing, ion chromatography is the primary method for measuring residual salts and counter-ions like trifluoroacetic acid (TFA) or chlorides. These substances often bind to peptides during synthesis and add physical weight to the final freeze-dried powder. To ensure accuracy, a suppressor removes background electrical noise so a detector can measure specific ions leaving the column. This process allows a lab to calculate the true active peptide mass versus the weight of residual contaminants. Understanding these levels is vital because high residual TFA means you receive less active peptide than the total weight suggests, which can also affect the safety and bioavailability of the product.

Ion chromatography is different from purity and identity testing

Reversed-Phase HPLC (RP-HPLC) measures peptide purity by separating molecules based on their water-repelling properties to identify peptide-related impurities.
Mass Spectrometry (MS) verifies the identity of a peptide by determining its exact molecular weight.
Ion chromatography (IC) focuses exclusively on measuring the small ionic salts and counter-ions attached to the peptide.

Ion chromatography measures residual ions to determine true peptide content

Ion chromatography is different from purity and identity testing

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