Chromatography Forum

Hi,

I'm injecting into a microscope flow cell.

My main question is, I've got 3 syringe pumps simultaneously pumping injection loop samples (3 X ~25uL ) into a 7-port manifold (~15uL swept vol). Will these samples mix, or will they output as laminar streams? I wanted to avoid agitation because our biological complexes tend to fall apart with shear force.

Another question, since I can't exactly measure it, does anyone have a rough estimate of how much unintentional mixing/dilution will occur between two inline samples? In other words, if I don't want two samples to mix, how much volume should I introduce between the two? I'm using 0.010 ID PEEK tubing if it matters...

Any other tips for a fluidics newbie?

Sorry for the basic questions (and for not knowing the lingo), and thanks for the help

It's outside my core area, but the answer is "it depends". On things like:
- flow velocity
- viscosity
- is the tubing straight or coiled, or . . .
- how long is the tubing.

If you want to avoid mixing, find a way to introduce a small air bubble between your injections similar to the old AutoAnalyzer (http://en.wikipedia.org/wiki/AutoAnalyzer)