http://www.sge.com/support/faqs/hplc/hplc HPLC FAQs http://www.sge.com/support/faqs/hplc/hplc/do-you-have-an-equivalent-column-to-___- SGE do not have "equivalent columns" as the only true equivalent for a HPLC column is the same phase called by a different name. However, if you search by the brand of column that you are looking for, the search results will list columns that will provide very similar or better chromatography to the competitor's columns. If the column that you are looking to replace is not listed, please contact us for recommendations. http://www.sge.com/support/faqs/hplc/hplc/do-you-have-an-equivalent-column-to-___- Thu, 30 Nov 2006 14:50:29 +1100 http://www.sge.com/support/faqs/hplc/hplc/how-long-do-sge-columns-last As a rough guide, HPLC columns will last from 3 to 12 months depending on how they are used. HPLC column longevity is significantly improved when guard cartridges are used and columns that are only used for clean samples with unbuffered, or weakly buffered mobile phases can last for a very long time. If dirty samples are routinely injected onto a column without a guard cartridge, the column may only be useful for two weeks. Similarly, if a column is used under extreme conditions (e.g. using a buffer with a pH outside the recommended range), then the column would also only last a few weeks. Although every HPLC column is used differently and it is usage that dictates column lifetime, SGE columns will last as long or longer than comparable competitors' columns under the same conditions. http://www.sge.com/support/faqs/hplc/hplc/how-long-do-sge-columns-last Thu, 30 Nov 2006 15:06:06 +1100 http://www.sge.com/support/faqs/hplc/hplc/which-sge-c18-phases-can-be-used-with-100-aqueous-mobile-phases The Exsil ODS columns can be operated with 100% aqueous mobile phases. Wakosil II C18 columns require 5% (10% is better) organic for reproducible chromatography as phase collapse can occur in 100% aqueous solution. N.B. phase collapse can be reversed by reconditioning with 100% methanol. http://www.sge.com/support/faqs/hplc/hplc/which-sge-c18-phases-can-be-used-with-100-aqueous-mobile-phases Thu, 30 Nov 2006 15:07:04 +1100 http://www.sge.com/support/faqs/hplc/hplc/will-i-get-identical-results-using-an-sge-alternative-column The selectivity, and therefore the retention times, of any two different column brands will always be slightly different, even if they are the same phase (e.g. (C18)). Any new column will be slightly different, but by optimizing the mobile phase, a separation can be obtained which is very similar to the previous column. For example, when switching to SGE's Wakosil II 5C18 RS column, increasing the proportion of the organic component (usually acetonitrile or methanol) by 5 - 10% will give a very similar separation to the previous column. In most cases, this will yield sharper peaks and in most cases better resolution between peaks. http://www.sge.com/support/faqs/hplc/hplc/will-i-get-identical-results-using-an-sge-alternative-column Thu, 30 Nov 2006 15:05:01 +1100