Many stationary phases and columns in NP-LC can be used in HILIC analysis. So what is the difference between the stationary phases of NP-LC and HILIC.
There is none. HILIC is a mode or variation of chromatography, not a specific support or stationary phase (you do not need to buy an "HILIC" column). You can read a clear explanation of HILIC at the link provided below. I hope you find it useful.
"Hydrophilic Interaction Chromatography (or HILIC)" http://hplctips.blogspot.com/2012/03/hydrophilic-interaction-chromatography.html
http://hplctips.blogspot.com/2012/03/hydrophilic-interaction-chromatography.html
There is none. HILIC is a mode or variation of chromatography, not a specific support or stationary phase (you do not need to buy an "HILIC" column). You can read a clear explanation of HILIC at the link provided below. I hope you find it useful.
"Hydrophilic Interaction Chromatography (or HILIC)" http://hplctips.blogspot.com/2012/03/hydrophilic-interaction-chromatography.html
http://hplctips.blogspot.com/2012/03/hydrophilic-interaction-chromatography.html
HILIC is normal phase chromatography. If a gradient is run, one goes from relatively non-polar organic solvents to more polar aqueous solvents. Many of the stationary phases are the same for "HILIC" columns and normal phase columns. Silica, diol, amine, and alumina are all stationary phases that are run as both normal phase and HILIC. in the old days, HILIC was called "aqueous normal phase".
For flash chromatography, here are some examples:
http://www.isco.com/WebProductFiles/Applications/101/Poster_and_Paper_Reprints/Strategies_for_the_Flash_Purification_of_Highly_Polar_Compounds.pdf
http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN78_HILIC_Purification_Strategies_for_Flash_Chromatography.pdf
http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN84_RediSep_Rf_Gold_Silica_and_Highly_Polar_Solvents.pdf
For natural products solvent and column screening, I do something I call "wide polarity range chromatography"- since the active compound is unknown, using this technique on different columns tells me which columns and solvent systems will work well. I can then simply use the columns and solvents which work well to scale up my purification. In these examples, one can see that HILIC is merely an extension of normal phase into a more polar solvent system (water).
http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN77_Wide_Polarity_Range_Chromatography.pdf
http://www.isco.com/WebProductFiles/Applications/101/Poster_and_Paper_Reprints/New_Techniques_In_Extraction_Column_Screening.pdf
I agree with the above. HILIC is just a different name for normal phase chromatography. In this case, silica is a common stationary phase (no C18) and the mobile phase starts out nonpolar and becomes more polar during the gradient.
Here's a paper that explains the difference-Hydrophilic interaction liquid chromatography (HILIC)—a powerful separation technique. HILIC is variation of normal phase silica, but the mode of separation is more complicated. HILIC includes normal phase silica either bare, amino, or cyano functionalized and addition of mobile phase modifier such as ammonium acetate to mobile phase similar to NP-LC.
Even though the same silica phase can be used in NP mode and HILIC mode, you must dedicate a column either in one mode or the other. It is almost impossible to completely displace any one type of solvent from the silica surface, and switching back and forth will result in completely altered and unpredictable selectivity and mode of separation. Therefore, if you need NP silica, buy NP columns (they are shipped with hexanes); if you need HILIC, buy HILIC columns (they are shipped in ACN-water).
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