Chromatography Forum

Hi Everybody,

I have a question on transferring the method from Perkin elmer to Agilent Technologies Headspace sampler.

Following are the headspace parametres for PE clarus 500

Nitrogen pressure:15.0 Psi through HS
Column flow : 5.6 psi
Pressurizing time : 3.0 min
Injection time : 0.07 min
Withdrawl time : 0.1 min


But with the Agilent I didn't find the nitrogen pressure through HS. Can any body explain where can I adjust this flow?

And also can I apply these parametres as it is to Agilent HS or shall I need to adjust these times?

We tried with the same parametres on Agilent HS , but our %RSD for replicate injections is coming high.

Can any body explain/suggest me what I can do further.

Thanks in advance,

Bhaskar

Bhaskarr

The Perkin Elmer HS uses timed injection, does it not?

The Agillent HS uses a fixed loop injection, does it not?

The parameters are not transferable.

best wishes,

Rod

I do not think that you can take the method that you use on the PE Headspace sampler and transfer it to the Agilent system as both use different sampling techniques. The PE system uses I believe the Balanced pressure mode of sampling whereas the Agilent uses a fixed sample loop.

Gasman

Thanks for the response,

as my vendor has only PE headspace sampler, he developed the methods on PE instrument only.

Now we want to receive the method, do I need to revalidate with the Agilent headspace sampler? If so which parametres I can play with?

Any suggessions please.

Thanks in advance,

Bhaskar

heating time and temperature, pressure and time used to pressurize the vial, and column flow rate should remain the same.

What will have to be adjusted for the Agilent HS analyzer is the size of your sample loop to get approximately the same amount of sample onto your column.

You will find the efficiency of the injection will not be as good as with the timed pressure balanced injection technique of the PE but hopefully the chromatography will be acceptable.

best wishes,

Rod

Hi Bhaskar

The two systems have different operating priciples, so you cannot just transfer the settings.

Use the split ratio to get the peaks to an acceptable size and width - the default sample loop on the Agilent is too big for a splitless transfer to a capillary column (which I presume you are using) , but changing the loop is a pain.

Rod, could you enlarge a bit on your comment about the efficiency of injection ?

Peter

The injection using the PE system introduces a minimum of dead volume.

The kind of sample loop, its ID and length, and the ID of the ports in the valve can affect the plug transfer to the column using the Agilent system.

best wishes,

Rod