Blank Run

hi

that is column related issue

please conditioning the column and detector and check

Column : HP-5 30x 0.32x0.25,

Hi Krishna

Thanks,  I have conditioned the column on Friday for about 2-4 hrs with the above condition.  I believe both the column conditioning and the Detector conditioning is same.  Correct me if i am wrong.  I am using He as a carrier gas.  If anything needs to be changed in the above conditioning method please advise me.

Regards

Revathy

Hi Revathy,

It seems like the conditioning method is pretty good. However, you do not need to go maximum temperature all the time, generally; 30degC above the analysis method for Inlet/Detector/Column will also work unless you have high boiling compounds. Keeping the column temperature lower than the recommended will help to prolong the life of the column.

So, back to your original question. The 3 blanks shows that the residue compounds in the system are reducing which is good. If you set the Y-scale same as the first Blank, then you can see that the baseline is getting better (or you can try overlaying the 3 Blanks). If you still see the residue compounds even after much conditioning, then; you may want to clean the inlet with some MeOH or replace the Split Vent Trap Cartridge or clean the Split Vent copper tubing. These are some of the possible places where contamination can occur.

Hope these are helpful.

Regards,
Kelvin Tan

As per my experience there is some issue in the method 

For 0.32 mm ID you are using the column flow as 22.77ml/min and the observed pressure is 13.198 psi is the absolutely wrong concept.

For 5ml flow it self it will cross the pressure as you mentioned.(13.198 psi)

I think there is a leak in the GC instrument or flow lines or column was not fixed properly or there might be issues in your instrument EPC

So kindly consult the engineer to resolve the issue

Check the instrument method with the development team, that much flow for 0.32 mm id is not recommendable

columns will get  damage easily.

As per my experience there is some issue in the method 

For 0.32 mm ID you are using the column flow as 22.77ml/min and the observed pressure is 13.198 psi is the absolutely wrong concept.

For 5ml flow it self it will cross the pressure as you mentioned.(13.198 psi)

I think there is a leak in the GC instrument or flow lines or column was not fixed properly or there might be issues in your instrument EPC

So kindly consult the engineer to resolve the issue

Check the instrument method with the development team, that much flow for 0.32 mm id is not recommendable

columns will get  damage easily.