简介:侯先生 13691497252 High performance liquid chromatography (HPLC) methods must be optimized to provide the greatest selectivity and sensitivity, and the best peak shape. Unfortunately, many analysts consider switching the简介:侯先生 13691497252 High performance liquid chromatography (HPLC) methods must be optimized to provide the greatest selectivity and sensitivity, and the best peak shape. Unfortunately, many analysts consider switching the stationary phase—the heart of the HPLC system—only as a last resort. Too often analysts coax the stationary phase to perform a non-native separation by using modifiers and ion pairing agents, which leads to reduced sensitivity and equilibration problems (the C18 phase is the most often misused). Selection of the proper stationary phase for your separation can improve LC sensitivity, analyte retention, and peak shape without the use of modifiers or ion pairing agents. For example, Restek’s Allure™ PFP Propyl and Ultra PFP HPLC columns easily perform separations of many basic analytes.
Research shows the Allure™ PFP Propyl stationary phase not only provides the greatest retention and capacity factor (k') (Figure 1) for basic analytes such as beta blockers and tricyclic antidepressants, but also the best peak shape. “…The results indicate that both the fluorine groups and the propyl chain are important on the phenyl ring to obtain the best peak shape and retention of the basic solutes when ammonium formate:acetonitrile (10:90) is used as the mobile phase.”1 As peak asymmetry is improved, sensitivity is increased.
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