Categories
Monoliths Theory

Separation of small molecules: surface area vs. gel porosity

Generally, methacrylic acid is used as a charge-bearing agent for generation of electroosmotic flow in capillary electrochromatography. However, methacrylic acid has a significant effect on the morphology of the monolithic stationary phases based on styrene – divinylbenzene system as showed recently by group in Prague.

The monolithic material prepared without methacrylic acid in the polymerization mixture showed a very low surface area of 0.1 m2/g, whereas the surface area of organic polymer monolith with methacrylic acid increased significantly up to 261 m2/g. The addition of methacrylic acid in to the polymerization mixture improves also separation power of prepared monolithic columns. Figure 1 shows the separation of the mixture of small molecules on the column without (A) and with (B) methacrylic acid in the polymerization mixture.

Categories
Chromatography Theory

How to get speed in HPLC

Fast HPLC

Couple of days ago, I mentioned on Chromatographer’s facebook page article by Peter Carr about speed in HPLC published in Analytical Chemistry. There are two parts in the article: (i) critical comparison of different approaches how to reach speed in HPLC and (ii) theoretical background of speed and efficiency optimization in high performance liquid chromatography.

Categories
Troubleshooting

Communication problem with Chromeleon 6.8

Dionex Logo Usually, I leave instrument’s computer up and running for long periods of time. No surprise that after several weeks there is significant amount of Windows Updates ready for installation. This week I had to reboot my system (Dionex Ultimate 3000) and during this occasion several new updated were installed.

After that I started to have problems with connection to the Chromeleon server.

Categories
Monoliths

One column fits all – Hypercrosslinked monoliths

One column fits all was title of my poster presented at HPLC 2010 in Boston that described the preparation and characterization of hypercrosslinked monolithic stationary phases and their application in several chromatographic modes. We summarized poster’s results and submitted them as a paper in Journal of Chromatography A.

Categories
General Monoliths Theory

My HPLC books

Today, I would like to describe my favorite chromatographic books: from one I bought even before I (really) knew what chromatography is to one which has chapter with my name on it.