head space injection

[rajdeeproy]

Dear all

I wanted to inject 500ul of sample in 1ml loop size. Is that possible. I heard that the sample size should be three times the loop to remove any dead volume.

please give me some information.

rajdeep

[chromatographer1]

Normally you wish to sweep the loop of any residual carrier gas from the previous injection. (3 times the internal volume is recommended)

Why?

To inject consistent amounts of sample as most analytical methods which perform accurate measurements require it. If you do not require consistent amounts then you do not need to sweep the loop, but I believe that is very rarely done.

best wishes,

Rod

[rajdeeproy]

so how should i go about. I am using varian CP3800 with gas sampling valves, which can be attached to different loops.