What Colona has to offer - the most important info
147 RP columns (as of 2021, annual updates) are compared; by means of rigorous tests the similarity/difference (equivalence/orthogonality) of the columns and their suitability for the separation of certain analyte types is measured. Note that this is not about determining optimal conditions for the separation of certain substance classes; it is exclusively about column comparison according to strict test criteria and based on own measurements. The results and statements are based on these measurements.
- “Comparison" and “Selection" are the two most important functions of the tool. The (direct) comparison of columns should be interesting especially in routine operation ("I am looking for an alternative column to..."), in method development the focus is more on finding a suitable column ("I am looking for a column that..."). You can start directly with the overview selectivity map; here you can work with filters if you wish (limitation to manufacturer, functional group, porous/core shell etc.). Or you decide for the start questions: "Similarity to...", "Difference to...", "Selective for...“ Or if necessary you go to "unknown sample?"
- It has been shown that the character of the phases (polar or non-polar?) and thus their similarity are presented quite accurately in the overview selectivity map.Explanation: The higher the alpha value EB/Fl (selectivity factor ethyl benzene/fluorenone) on the Y-axis, the better the hydrophobic selectivity of the corresponding column. For example, Cortecs C18 or YMC Pro C18 RS show good selectivity for the separation of non-polar and polar molecules, neutral, non-ionic components or weak acids/bases. On the other hand, the larger the alpha values Tri/o-Ter (triphenylene/o-terphenyl) on the X-axis, the greater the steric selectivity/molecular recognition of this column and, indirectly, its polar selectivity. For example, Poroshell 120 PFP or Acclaim PA C16 separate planar/non-planar molecules, isomers or polynuclear, unsubstituted aromatic compounds and small polar molecules well. In addition, their separation on the selectivity map is a clear indication of the similarity/difference of columns. With the help of filters you can limit the selection of columns, for example only PFP columns, only Core Shell, only columns from company X, etc.
- The bar charts are probably best suited for fast, focused information: "Best" hydrophobic, steric, aromatic or polar selectivity. As regards polar selectivity, the polar character should be considered somewhat more differentiated since different polar interactions are possible. A first indication of polar selectivity - besides the overview selectivity map - is provided by the bar charts "steric" and "aromatic selectivity" (accessibility of silanol groups, π-π interactions). An indication of stronger polar interactions or hydrogen bonds - e.g. for acids – is given by the alpha value Phe/EB (phenol/ethylbenzene). Finally, the alpha value Benz/Phe (benzylamine/phenol) could be seen as a measure of the ratio of ion exchange/hydrogen bonds. An irreversible adsorption of the strong base benzylamine (alpha value Benz/Phe nominally greater than 6) indicates a tendency of the corresponding stationary phase to strong cation exchange interactions, a strongly polar character. Based on the selectivity maps and the bar charts, alternative columns or, conversely, quite different columns can be selected for orthogonal tests (e.g. to check the peak homogeneity) or for equipping a column changer.
- Selectivity web charts allow quasi as pictograms a direct, optical comparison of columns.
- Here you will find the numerical values for the physico-chemical properties of the columns used as well as all other data such as selectivities, etc.
- Here you will find brief information about the chemical character of the columns.
- Here you can see the most hydrophobic phases as well as the most polar.
- And finally, further information and explanations can be found in the FAQ.