What is ion pairing agents?
Ion-pairing agents are compounds that contain both an ionic functional group and a hydrophobic portion, such as a hydrocarbon chain.
What detectors are used in ion pair chromatography?
UV detectors are widely used. Therefore ion-pair reagents must lack UV absorption themselves to obtain highly sensitive detection of samples. The UV absorption of sodium alkanesulfonates and quaternary ammonium salts is minimal so that these reagents can be used for reliable HPLC analysis.
What is use of ion pair reagents?
Ion Pairing Reagents are use as mobile phase additives, which allow the separation of ionic and highly polar substances on reversed phase HPLC columns.
Why is formic acid used in HPLC?
One of the most important uses of formic acid in liquid chromatography is as a buffer component of aqueous mobile phases (formic acid-sodium formate or formic acid-ammonium formate solutions) when pH (values around its pka, 3.75) must be controlled to achieve separation of target compounds with acid-basic properties.
How do ion pairing agents work?
In ion pair chromatography, the solute ion is distributed between the mobile and the stationary phase together with an ion of opposite charge (a so-called counterion). The technique is often used in reversed-phase chromatography as a convenient method to control the retention of solutes.
Why is TFA used in HPLC?
TFA is widely used as a mobile phase additive in the HPLC separation of biological molecules, such as proteins and peptides, because it acts as an ion-pairing reagent and equilibrates quickly so that it can be used with gradient elution.
What is the use of ion pair reagent?
Is TFA formic acid?
Trifluoroacetic acid (TFA) is typically used for RPC of peptides (at 0.1% v/v) in conjunction with UV detection. Formic acid is the usual selection; acetic acid less common. Problem: Generally much poorer peak shape and lower peak capacity. with formic (or acetic) acid than when TFA is used.
What are the parameters for ion pair chromatography?
Briefly, for the separation of a particular set of analyte ions the parameters that are most important are type and concentration of ion pair reagent, type and concentration of organic modifier, and mobile phase pH. By varying these parameters while keeping the others constant within sensible ranges, an acceptable separation is usually obtained.
How are ion pairing agents used in HPLC?
The use of ion-pair reagents can be a handy tool in improving retention and peak shape of ionizable compounds in HPLC (typically reversed phase). Here’s how: Ion-pairing agents are compounds that contain both an ionic functional group and a hydrophobic portion, such as a hydrocarbon chain.
What do you need to know about ion pairing agents?
Technical Tip: Ion-Pairing Agents 1 Overview. Ion-pairing agents are compounds that contain both an ionic functional group and a hydrophobic portion, such as a hydrocarbon chain. 2 Interaction Mechanisms 3 Common Drawbacks. 4 New Technologies. 5 Ideal Ion-Pairing Scenarios.
When to add an ion pair reagent to the mobile phase?
The purpose of adding an ion pair reagent to the mobile phase is usually to change the retention time of ionic analytes.