Apr 20, 2016 · Jack Cochran’s new column “Practical GC” provides readers with practical advice and new experimental evidence for how to get the best results from their gas chromatography (GC) systems. This instalment looks at understanding and using split ratio for …

Split Injections - Maximizing Sensitivity Increase Injection Volume • liner dependent (use the Pressure-Volume Calculator) • 2 uL maximum Reduce Split Ratio • go from 50:1 to 10:1 • 5:1 practical lower limit for liquid injections (for 250 - 320 um i.d. columns) • 1:1 possible for gas injections with correct liner Use Pulsed Injection

To calculate the split ratio, use the following equation: Ratio Split flow rate==column flow rate SF F c Because both rates are in mL/min, the units will cancel. However, this is only an approximation because the two rates are not measured under the same conditions of temperature and pressure. 222

Split ratio: The split flow divided by the column flow (e.g., 100:1 means 1% of the sample enters the column). Instead of thinking about individual flows, just think about split ratio . On most modern GCs, you simply input the split ratio, and the instrument sets the flows for you.

Learn how to choose the right column the first time. Optimize separations for the best balance of resolution and speed. Troubleshoot quickly and effectively based on chromatographic symptoms. You can improve lab productivity by assuring that speed and resolution are optimized.

Aug 3, 2019 · Split ratio of 1:X is not rare. For example, in an Agilent presentation, slide 11, it is mentioned that the minimum recommended for the split ratio varies from 1:2 to 1:75 depending on the column mm.

Jun 19, 2012 · The function of GC inlet liners is simply to provide a space for your injected sample to be vaporized and transferred to the column. Ideally, the space in which the sample is vaporized should be as inert as possible, so your analytes do not adsorb or interact in any way with the inlet.

The split ratio indicates “the ratio between the column fow rate and the split fow rate” and indicates the approximate branching ratio of the injected sample.

Always optimize the column flow rate by using linear velocity.

Using merely a flick of a software-controlled valve the amount of injected analyte can be instantly varied before an injection is made. This is called the split ratio and is a function of the ratio of gas flows through the GC’s injector, all controlled by pressure/gas flows in …