Liquid Chromatography

In HILIC, small variations of the elution conditions often result in differences in the retention greater than the ones observed in RPLC. Therefore, particular attention has to be paid to the selection and the preparation of the eluents. 

A common and useful classification of the HILIC stationary phases is on the basis of the presence of functional groups on the surface and their charged state: they can be divided in unbounded and bonded phases, and these ones are classified in...

This technical article discusses the injection volume, column temperature and detector wavelength adjustments.

In this article we’ll look at flow-rate and particle-size adjustments.

In this article, we’ll take a closer look at some of the potential adjustments related to the column.

The second part of this series focuses on the allowable adjustment in the ratio of aqueous (A) to organic (B) components of a reversed-phase mobile phase.

In the first part of this series, an overview of the concept of method adjustment vs method change in reversed-phase HPLC is presented.

PEEK (poly-ether-ether-ketone) fittings and tubing are in widespread use for HPLC applications. The convenience of using your fingers instead of a wrench to tighten the fittings and the flexibility of the tubing make PEEK the material of choice for...

As part of the HPLC Master Classes that I teach, I start each class by gathering questions or topics that the attendees would like to know more about. In a recent class in London, one of the topics was the causes of excessive retention – a method in...

This technical article takes a closer look at the influence of temperature on the separation.

In the previous three instalments of this series ('#7: Fundamental Resolution Equation, Part 1', '#8: Fundamental Resolution Equation, N', '#9: Fundamental Resolution Equation – Alpha'), we’ve looked at the fundamental resolution equation

In the previous two articles ('#7 Fundamental Resolution Equation, Part 1' and '#8 Fundamental Resolution Equation, N'), we’ve looked at the fundamental resolution equation

In the previous article we began our study of the fundamental resolution equation

In our last Back-to-Basics discussion (#6 Resolution), we looked at the way we measure resolution, R_s, from a chromatogram using the following equation:

This technical article introduces the solvent-strength nomogram, a tool to pick the (approximately) equal strength of one solvent from another.