My samples are typically in heptane and my standards are in either acetone/heptane, heptane, or methanol. Would there be an effect on quantitation? I am using a S/SL injector at 240C with a 10:1 split flow (hydrogen). Thanks!
My samples are typically in heptane and my standards are in either acetone/heptane, heptane, or methanol. Would there be an effect on quantitation? I am using a S/SL injector at 240C with a 10:1 split flow (hydrogen). Thanks!
Hi Anatoly,
if the vapour pressures of the solvents are comparable it doesn't matter that you inject different solvents and even if they are very different like water vs. any organic solvent, the error is small.
In direct injections and cold-on-column it doesn't matter at all. For split you might loose a little due to more or less vapour in the injector and therefore more or less leaving through the septum purge. In your case I wouldn't worry.
Anyway you can dissolve the same amount of a component in both solvents, inject them separately under the same conditions, and compare their peak areas (FID) or peak heights (TCD) and calculate a correction factor. In reality nobody does 
.
Regards,
Norbert
Hi Anatoly,
if the vapour pressures of the solvents are comparable it doesn't matter that you inject different solvents and even if they are very different like water vs. any organic solvent, the error is small.
In direct injections and cold-on-column it doesn't matter at all. For split you might loose a little due to more or less vapour in the injector and therefore more or less leaving through the septum purge. In your case I wouldn't worry.
Anyway you can dissolve the same amount of a component in both solvents, inject them separately under the same conditions, and compare their peak areas (FID) or peak heights (TCD) and calculate a correction factor. In reality nobody does .
Regards,
Norbert