gas phase internal std

[pueblito]

Dear Chromatographers.

We are implementing the EPA TO-17 method. It calls for gas phase internal standard transfer onto each sorbent tube.
One of options is to transfer from cylinder to a loop and then automatically to the sorbent tubes in the TD instrument. Nevertheless for the moment We can´t implement this setup. The question is, Could we use instead a pressure regulator, a syringe adapter and a gastight syringe to take an aliquot of the gas and inject it manually onto each tube?

Best regards.

[rb6banjo]

I don't use this method but I don't see how what you're doing with the syringe is any different than what is done with the loop. It's all about getting a known and reproducible amount of the standard on the sample tube. It seems to me that you can accomplish that either way. However, I don't know what an auditor might say......

[pueblito]

That´s true, The auditor´s point of view about this.
He would ask for a statistic demostration of equivalence.

Thank you rb6banjo.