Full Loop Injection and Syringes

[lgchrom]

Hi!

Let's say we have a 50 microliter loop. A good full loop injection would mean that 5-6X the loop volume should be injected right?

In order to do that we would have to pass at least 250 microliters through the loop. Is it ok to inject such a volume with a 100 microliter syringe by injecting 3 times x 100 microliters? Or would that cause air air bubbles to be injected?

[Markus Laeubli, Metrohm]

To fill a loop properly, in our experience (ion chromatography) a 3-times rinsing is good enough.
But I would not recommend to do it in several steps. Any removal of the sysringe might lead to backflow or to drawing of air.

[HPLCCONSULT]

As previously stated, for the best result the 'rule' is three times the volume to overfill and flush the loop, not five or six times. DO NOT remove the syringe from the injector. Select a syringe with the correct capacity for the job.

[lgchrom]

Thanks,

so a 250micro liter syringe would be the proper size for a full loop injection of a 50 microliter loop.