Is C18 column polar or nonpolar?
A C18 column is an example of a “reverse phase” column. Reverse phase columns are often used with more polar solvents such as water, methanol or acetonitrile. The stationary phase is a nonpolar hydrocarbon, whereas the mobile phase is a polar liquid.
How does anion exchange HPLC work?
Anion exchange chromatography is a form of ion exchange chromatography (IEX), which is used to separate molecules based on their net surface charge. Anion exchange chromatography, more specifically, uses a positively charged ion exchange resin with an affinity for molecules having net negative surface charges.
How does an anion exchange column work?
Anion Exchange Column Design Ion exchange chromatography is used to separate charged molecules. In an anion exchange column, the packing is positively charged and therefore retains negatively charged molecules by coulombic interaction. The bound molecules are eluted with an anion gradient.
When to use the sax anion exchange column?
1) Commonly used to separate compounds that are anionic in aqueous solution; 2) The SAX HPLC column is compatible with water and organic solvents, and methanol, acetonitrile, and water (including buffer salt solutions) can be used as mobile phases for analysis;
Which is the reversed phase column in HPLC?
Reversed-phase (RP) columns (e.g., C18) are most widely used for HPLC separations. 1 However, their use is limited by dewetting in highly aqueous environments, 2,3 peak tailing for basic molecules 4–6 and insufficient retention of hydrophilic compounds (e.g., organic acids).
Which is longer anion exchange column or C18?
5) The equilibrium time of the anion exchange column is longer than that of C18. 4) Regeneration: connect the column in the opposite direction, flow rate 0.4ml/min, and elute 30ml respectively, and then 1M ammonium nitrate—40% methanol solution—isopropanol—water—eluent, and then pack the column in the specified direction.
Which is the best column for ion exchange?
These quaternary amine strong anion-exchange columns are highly stable for aqueous and low pH mobile phases. Based on high purity silica bonded with an ion-exchange ligand, Hypersil GOLD SAX LC Columns provide outstanding peak shape and sensitivity.