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. [...]
Recently, I was browsing amazon.com products related to the chromatography keyword. To my big surprise, the number ten (at least in my results) was a “16 oz. Double Wall Insulated Tumbler with chromatography column alone – Paper Insert”. This is what I call a present for a chromatographer! I waited until our next order (Harry [...]
The last CASSS Discussion group focused on the possible advantages and disadvantages of high temperature and/or high pressure in a liquid chromatography. The Discussion group was hold as a debate – two experts against each other. The high temperature approach was defended by Nebojsa M. Djordevic (SANO CRO) and Michael W. Dong (Genetech) advocated the [...]
The recent progress in the column development brought to the market new type of highly efficient columns. These columns can be use either with standard HPLC instruments or with the instruments allowing separations at ultra high pressure (900 MPa). The conventional size of the column (150 x 4.6 mm) has been decreased significantly. The typical [...]
The inverse application of the size-exclusion chromatography (SEC) concept, inverse size-exclusion chromatography (ISEC) [1], utilizes a set of molecular probes with defined sizes to determine pore dimensions, and is also referred as chromatographic porosimetry [2]. ISEC provides an alternative to mercury porosimetry or nitrogen adsorption for the determination of the pore size dimensions and the surface area of [...]
Superficially porous particles with thicker outer shells were used extensively for liquid-liquid chromatography [1] and as the support for early bonded-phase packings in reverse phase HPLC [2]. Structure of particles Nowadays superficially porous particles typically have a 5-µm solid core and a ~ 0.25 – 1 µm thick outer shell with 30-nm pores. But, the thinner the shell, the [...]
It is known that the kinetics of mass transfer in wide pore bonded silica can be slow, because of restricted intraparticle diffusion and, furthermore, remaining active surface sites can give rise to undesired interactions. All together, these effects cause additional peak dispersion in high performance liquid chromatography and often considerable loss in recovery of biological [...]
Liquid chromatography offers numerous possibilities how to separate samples of interest. By changing the composition of mobile phase and/or character of stationary phase the separation efficiency and selectivity can be completely change. Read more about main liquid chromatography modes. Size-exclusion chromatography (SEC) Size-exclusion chromatography (also known as gel permeation chromatography, GPC) is separation technique, where [...]
Chromatography is analytical chemistry method which is used (and useful) for the separation of complex mixtures of chemical compounds. The main mechanism of the separation is repeatable distribution of the tested compound in between two different phases. Usually, one phase is solid, fixed in the separation device and the other is moving and flows through [...]
Analytical chemist. Amateur photographer. Occasional traveler. Lazy graphoman. Wannabe entertainer. Boring moralist ...
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Chromatographic articles