Liquid Chromatography

Size-Exclusion Chromatography (SEC) is a powerful technique for protein characterization that requires an understanding of the principles to be successful. In this open-access course, we will discuss the history and science of SEC, its strengths and...

Successful chromatographic separations are as much about preventing the interactions you don’t want, as it is about creating the interactions you need. This open-access course is designed to take you from beginner to advanced in controlling the...

Have you ever wondered how the LC column creates a separation? What attributes are important, what do they do, and how to use them to your advantage? This open-access course is designed to take you from beginner to advanced in understanding column...

Join scientists from around the world at the 50th sequel of the longest-running, largest, and most recognized conference in the world covering all aspects of Separations and Analyses carried out in Liquid Phase. HPLC 2022 will take place on June...

This eBook demonstrates the six coveted advantages you gain with the Agilent 6546 LC/Q-TOF.

A reader wrote me recently asking what would happen if he injected his sample, which came dissolved in hexane, into a reversed-phase mobile phase of methanol-buffer. The first answer is that this is not a good habit, but is it possible? We’ll see.

I recently had an inquiry from a reader of 'HPLC Solutions' that comes up with some regularity in the HPLC troubleshooting classes that I teach: “Will I damage the column by getting air in it?” Let’s consider the possibilities for a moment. One...

A reader asked me if she was in danger of shortening the lifetime of an HPLC column by removing it after each batch of samples and storing it. This also raised the related question about expectations of shorter column lifetimes if the same...

What happens if your favourite HPLC column accidentally rolls off the bench and lands on the concrete floor of the lab? Is it ruined?

After I wrote an article on in-line Degasser (HPLC solutions #72), I immediately received some reader feedback on a specific failure, which was published in 'Failed Degasser' (HPLC solutions #73). Since that time I have been collecting occasional...

A reader reported a problem blockage of a column packed with one of the newer shell-type packings. The mobile phase A comprises a mixture of 0.1 M KH₂PO₄, 0.05% triethylamine (TEA), and 150 mg/L EDTA adjusted to pH 7.5 with NaOH. The B-solvent is a...

A reader recently emailed me a question that went something like this: “I’m using LC-MS/MS to analyse a biomolecule that I have isolated from tissue by LC-MS/MS. The lowest point on the calibration curve that I prepared is 0.1 µM. All the samples...

A reader recently asked a question about the use of the peak-purity function of his diode-array UV detector (DAD). The question related to whether or not he could detect the presence of enantiomers, stereoisomers, diastereoisomers, or epimers with...

The dwell volume comprises all the HPLC system volume between the point the solvents are mixed to the head of the column. For high-pressure-mixing systems, this includes the mixer, connecting tubing, and sample loop. For low-pressure-mixing systems,...

In a previous article (Dwell Differences, HPLC Solutions #85) we saw an example of how the appearance of a chromatogram could change when a gradient method was run on two HPLC systems of differing dwell volume. In this article we’ll look at a simple...