LCGC The Peak - July 2008 - (Page 17) JULY 2008 THE PEAK 17 Figure 9: Separation of compounds A-F using a C18 column under SFC conditions (5% methnaol in mobile phase, 2.0 mL/min flow rate): (a) 1500 psi, 30 °C; (b) 3000 psi, 30 °C; (c) 1500 psi, 40 °C; (d) 3000 psi, 40 °C. optimization, it is readily possible to achieve baseline separations of complicated, structurally diverse mixtures (up to six components) that are co-eluted or closely eluted using a C18 column under reversed-phase HPLC gradient and isocratic conditions by using a C18 column and SFC conditions. Percent co-solvent and flow rate provided the most impact on the ability to separate the mixture on the C18 column using SFC conditions. Greater resolution with a lower percentage of co-solvent was observed on all three nonpolar columns under SFC conditions, consistent with the observations of Dolan (15). The two graphs (Figures 3d and 5d) showing the resolution versus percentage of co-solvent illustrate that a 5% decrease in co-solvent led to a major increase in resolution. This phenomena also was observed by others when they separated five imidazoles using SFC with a C18 column (16). Heat and pressure changes were implemented with minimal success in regards to increasing resolution. Increasing the oven temperature resulted in longer retention times, which from our experience, is reversed from the effect on retentions on polysaccharide-based columns
Table of Contents Feed for the Digital Edition of LCGC The Peak - July 2008 LCGC The Peak - July 2008 Contents From the Editor Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference Industry News Events Education LCGC The Peak - July 2008 LCGC The Peak - July 2008 - LCGC The Peak - July 2008 (Page Cover1) LCGC The Peak - July 2008 - LCGC The Peak - July 2008 (Page Cover2) LCGC The Peak - July 2008 - LCGC The Peak - July 2008 (Page 3) LCGC The Peak - July 2008 - Contents (Page 4) LCGC The Peak - July 2008 - Contents (Page 5) LCGC The Peak - July 2008 - Contents (Page 6) LCGC The Peak - July 2008 - From the Editor (Page 7) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 8) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 9) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 10) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 11) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 12) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 13) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 14) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 15) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 16) LCGC The Peak - July 2008 - Evaluation of Nonpolar Reversed-Phase Columns Under Supercritical Conditions (Page 17) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 18) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 19) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 20) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 21) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 22) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 23) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 24) LCGC The Peak - July 2008 - Enhancing GC–MS Analysis of Trace Compounds Using a New Dynamic Approach to Reducing Background Interference (Page 25) LCGC The Peak - July 2008 - Industry News (Page 26) LCGC The Peak - July 2008 - Events (Page 27) LCGC The Peak - July 2008 - Events (Page 28) LCGC The Peak - July 2008 - Events (Page 29) LCGC The Peak - July 2008 - Education (Page 30) LCGC The Peak - July 2008 - Education (Page 31) LCGC The Peak - July 2008 - Education (Page 32) LCGC The Peak - July 2008 - Education (Page Cover4)
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.