In Brief:

I was recently cleaning up some files and found an email from a great chromatographer, all-around scientist, and human; the late Andy Alpert.  The email was penned to favorably comment on one of my first LCGC articles (nearly a decade ago).  The topic, of course, was hydrophilic interaction liquid chromatography (HILIC). As he very much honored me with his comments, I’d like to return the favor by remembering him with my first blog for ASKkPrime.com.

Please visit https://www.chromatographyonline.com/view/retention-and-selectivity-stationary-phases-used-hilic for the full article.

Hydrophilic-interaction liquid chromatography (HILIC) is complex, often involving multiple interactions that may include partitioning, polar (adsorption), and ion-exchange forces. Different HILIC stationary phases offer these interactions to varied degrees.  For example, pentafluorophenyl phases supply mainly ion-exchange whereas bare silica columns offer both partitioning and ion-exchange. By understanding what the different phases provide and matching those interactions with the main differences in the target analytes, method development can be greatly facilitated. Recognizing the presence of these interactions and understanding how to control them is crucial for the development of robust and reliable methods. Successful method development in HILIC involves understanding analyte properties, selecting suitable stationary phases, screening the appropriate phases for selectivity, and optimizing/controlling the separation conditions. 

– HILIC often involves partitioning, polar (adsorption), and ion-exchange interactions.

– Understanding interactions provided by different stationary phases is essential for facile method development.

– Method development includes understanding differences in analyte properties and exploiting the attributes of stationary phases to impart separation.

– Screening, optimization and variable control are crucial for achieving effective and reliable separations.

In summary, success in HILIC chromatography relies on recognizing the presence of  the diverse interactions offered by various stationary phases and understanding how to effectively match the interactions to the target analytes.  Variables that impact the interactions need to be recognized and strictly controlled when present.

HILIC is a powerful tool and can solve many problems reversed-phase systems can not.  But like any powerful tool, if it is used incorrectly it can seem unmanageable. Spend a little time getting to know your phases and what variables interactions like ion-exchange respond to and I assure you, HILIC can be a good friend.

Thanks again Andy.  You are missed.