Chromatography Forum

if I make up a standard of toluene at 1ppm v/v and I inject it with a split ratio of 0.1:1 then does that mean first off that theoretically that 90.9% is going on column and the rest is going to vent?

so if my column flow rate was 5.6ml/min would that mean that flow to vent would be 0.56ml/min and flow to the column would be 5.04ml/min (0.1x5.6)?

finally what would the actual concentration of toluene be given the split ratio going to the column?

I'm curious as to why people worry about these academic gymnastics on sample injection. Why is it that you care about this? The latest installment was late October of 2015:

viewtopic.php?f=2&t=27580

In the end, if you are trying to quantitate toluene in your sample, as long as all injections are treated the same, it'll come out in the wash at the end. This comes up periodically I just wonder why?

if I make up a standard of toluene at 1ppm v/v and I inject it with a split ratio of 0.1:1 then does that mean first off that theoretically that 90.9% is going on column and the rest is going to vent?

so if my column flow rate was 5.6ml/min would that mean that flow to vent would be 0.56ml/min and flow to the column would be 5.04ml/min (0.1x5.6)?

finally what would the actual concentration of toluene be given the split ratio going to the column?

I doubt that there is any GC on the market that will give a split ratio of 0.1:1 (i.e. 1:10), and why would it be necessary, if the column and detector can handle 100 % of the sample they will handle 90% of it.

If the column flow rate is 5.6 ml/min then the flow to the column is 5.6 ml/min. I suspect that you are confusing total flow with column flow.

The actual concentration of toluene ?: that's easy; 1 ppm - you already know that from the concentration of the standard.

All the the GC manufacturers' web sites, and every basic book on GC has clear descriptions of what split inlets do, and how they do it.

Peter