Nowhere is the need for a truly ultra-inert base deactivated HPLC column more important than in high throughput analysis or LC-MS. Even subtle differences in silanol activity between columns can markedly affect the chromatography in the very short, fast columns typically used. In addition, any peak tailing due to silanol activity can have a profound effect on detection limits in high sensitivity assays. ACE ultra-inert base deactivated HPLC columns virtually eliminate the negative effects of silanols in HPLC separations. This unequalled performance is now available in 20, 30, 35 and 50mm length columns, with diameters from 1.0 to 4.6mm id The ACE columns are suitable for high throughput and LC-MS applications, and are the ideal choice for high volume screening assays used for drug analysis and combinational libraries where robust, reproducible columns are essential.
ACE LC-MS and Rapid Analysis columns are available in a wide range of lengths and internal diameters, to enable complete method optimization. Reduced column lengths are used to increase productivity (see Figure 31a) whereas reducing column diameter improves sensitivity and reduces solvent waste (Figure 31b).
As shown in the figures below, the optimum phase, column dimensions and evaluation conditions can be selected to simultaneously optimize productivity, reduce waste and increase sensitivity, whilst still maintaining baseline resolution.
ACE LC-MS columns, apart from being the most inert on the market, are also the most efficient, and are manufactured and validated to the same exacting standards as all ACE columns. Increased efficiency is an important benefit given the short columns typically used in LC-MS and rapid analysis applications. Analysis of the LC-MS signal intensity obtained for equivalent injections on different brands of 30 x 4.6mm C8 columns show significant baseline tailing on typical column brands, whereas the ACE column yields near perfect symmetry. Such peak shape improvements may be typically seen when using high efficiency, ultra-inert columns such as ACE.
Significant differences in efficiency, peak shape and selectivity are seen when analyzing pyridine - a small highly basic molecule.
Increased tailing and retention are indicative of undesirable secondary interactions between pyridine and silanol groups on the stationary phase surface. These interactions can also result in poor column reproducibility.
ACE LC-MS columns were independently tested and found to be the highest efficiency, most inert columns available.
