Advantages and disadvantages for HILIC columns ....

[LC_Master]

I just want to mention that HILIC is meant for retaining extremely polar compounds. It's works beautifully, but the drawback is that HILIC is fickle. You must get the pH exactly right.

I would go further to say first try Reverse phase, then try a PFP, and finally try a HILIC column in reference to the previous comment.

[Einar Ponten]

The fact that HILIC is suitable for "highly hydrophilic molecules" or "extremely polar compounds" is more of a feature than disadvantage... To quote LC_Master; "You must get the pH exactly right" seems to be problematic.

However, this is not true since optimising mobile phase pH is a nice way to modulate the selectivity by controlling analyte hydrophilicity.
Refering to the long list of phases by XL; Could it be that just being "a polar stationary phase" does not mean it is really suitable for HILIC? Should it then be denoted "HILIC column"?

[XL]

First off, I need to clarify that the "reversed-phase and ion-exchange mixed-mode phases" I wrote in my previous post was meant to be "reversed phase/ion-exchange mixed-mode phases." More information can be found in the following links. All three Acclaim Mixed-Mode columns (WAX-1, WCX-1 and HILIC-1) can be used in HILIC mode in addition to other capabilities:
Mentioned without examples (which I can provide upon request) in http://www.dionex.com/en-us/webdocs/488 ... 021407.pdf
Figure 8 in http://www.dionex.com/en-us/webdocs/658 ... PN2024.pdf
Figire 5 in http://www.dionex.com/en-us/webdocs/618 ... PN1963.pdf

In case I didn't make it clear, here is my point: all stationary phases that have hydrophilic surfaces can be used in HILIC mode, such as the long list (rather than a single phase) that I gave in my previous post.

[Bryan Evans]

An alternative choice to a HILIC column is Unison UK-Amino.
Molecular interaction occurs via normal phase / anion exchange:

http://www.silvertonesciences.com/files/TI316E.pdf

[Einar Ponten]

...and what is the advantage/disadvantage?

[Bryan Evans]

In terms of advantages of Unison UK-Amino as it relates to HILIC columns:

- NH2 phase allows for improved peak shape for reducing sugars
- Elution order can be different when compared to HILIC

Take for example for melamine and cyanuric acid,
under similar conditions the elution order is:

HILIC
1. cyanuric acid
2. melamine

Unison UK-Amino
1. melamine
2. cyanuric acid

So Unison UK-Amino is a nice alternative to HILIC phases.