Explore BrainMass

Types of stationary phases used for chiral separations in HPLC

Describe the types of stationary phases used for chiral separations in HPLC including structural requirements.

Solution Preview

The stationary phases for chiral separation can be classified into 5 main types. These types were first proposed by Irving Wainer and are hence also known as the Wainer classification.

Type I - those that differentiate enantiomers by the formation of complexes based on attractive interactions. These may be hydrogen bonds, p-p interactions, dipole stacking. The two main types of stationary phases in this type are pi-acceptor and pi-donor phases. The most common pi-acceptor phase is N-(3,5-dinitrobenzoyl) -phenylglycine bonded to n-propylamino silica. These columns are capable of separating a large range of compounds which include a pi-donor aromatic group.

Type II - those that involve a combination of attractive interactions and inclusion complexes to produce a separation. Most type II phases are based on cellulose derivatives. Columns available include microcrystalline triacetate- (MCTA), tribenzoate-, trisphenylcarbamate- and tris(3,5-dimethylphenylcarbamate)- cellulose. Some of the applications include separations of small aliphatic ...

Solution Summary

The solution describes the stationary phases for chiral separations.