In a typical separation, glucoraphanin and glucoiberin (two glucosinolates found in broccoli) were separated in ten minutes at a flow rate of 0.5ml/min using Zic-Hilic chromatographic media
Glucosinolates are anionic secondary metabolites which are phytochemicals found in cruciferous vegetables (eg, broccoli) and are of interest due to their role in the prevention of cancer.
These compounds can be readily separated using Zic-Hilic hydrophilic interaction chromatographic media.
An analytical method for the separation has recently been reported that employs an ammonium formate buffer (pH 4.5) with acetonitrile to provide baseline separation with a short separation time ['Improved hydrophilic chromatography method for the identification and quantitation of glucosinolates' by KL Wade, IJ Garrard and JW Fahey, J Chromatogr, in press].
This analytical method has a number of significant benefits compared to previously reported methods for the separation of glycosinolates.
One popular method employs ion-pairing reagents, which are not desirable as a desalting step is required if mass spectroscopic detection is required (as is frequently the case).
Other commonly used methods for the separation involve enzymatic desulphation followed by separation on a C18 column.
While this method is successful, it suffers from the disadvantage that the separated compounds are no longer biologically active nor can they be converted to isothiocyanates or other biologically active compounds.
The method based on Zic-Hilic is reported to be "much more robust and flexible, giving better separation of a greater range of glucosinolates, with a much longer column life".
