Chromatography Forum

Hi all

We presently have an knauer auto sampler in our HPLC system
Will it be possible to introduce an manual injector into the system, such that people can use either one of them according to convenience.... with out doing too many changes in the tubings ..?

with best wishes

That should be straightforward. I'd plumb the manual injector before the autosampler.

That should be straightforward. I'd plumb the manual injector before the autosampler.

hi ..
thank you very much .... i think i realised what you said ..
==since both the manual and auto sampler have the mobile phase running in them .. I can make one machine configuration with auto sampler and one with out ...
==attach both of them to the trigger for data acqusition
==case i with autosampler, the autosampler gives trigger
==case ii the rheodyne gives the trigger

did i understand u properly
and this plumbing shold work ...right ..??

we still are novices here .. can you just make a small diagram for tubing and upload it

I'm no computer genius, that's beyond my capabilities.

Pump to manual injector. Manual injector to autosampler. Autosampler to column. In this way an autosampler injection would not have to go through any dead volume of the manual injector. And autosamplers such as Agilent would just function as "tubing" before the column.

So whether you put manual before autosampler, or the other way around: if some extra dead volume is an issue, you may want to consider valves to isolate the sampling system not used.

We oftentimes make single injections using our autosamplers, we have used manual injectors rarely, and then just to plumb in to troubleshoot an autosampler. So I'm not even real sure why you want to do this.

did i understand u properly
and this plumbing shold work ...right ..??

Yes. In fact, I'd argue that while it's a good idea to have the one you use more often closer to the column, in practice it makes little difference. Just plumb them in series.

Pump -> manual injector -> autosampler -> column -> detector