Chromatography Forum

Hey all!

Anyone who have experience on this instrument/detector named above, have some sensitivity improving advice? I have some compunds that recently have almost gone from my chromatograms. (e.g.: Omethoate) Maybe it is happening because of the coloumn aging (half year old), but i have never used another options in the detector menu yet.
Anyone have some suggestions?

I'm running this instrument in slow flow rate (2,1 ml/min), phosphorous mode,
Tube voltage 510 V
Trigger level: 200 mV
Sampling delay 4,0 ms
sampling width 10,0 ms
Gain factor: 2
Make up gas (Type EFC13):
Air 17 ml/min
H2 13,0 ml/min
Air 2 : 10,0 ml/ min
Detector range: 10
Split ratio: initial: OFF then 0,75 min: ON 100, then 2,5 min: 20

So my goal would be to use any options to detect these compunds in spite of high standard concentration rates.

Thanks!

May be PMT aging?

Hi,
There are a few changes which you could utilise..
change liner/ septum, increase PFPD temperature (depending on what it is currently at) or you can also adjust the split valve so the tick tock is slightly off.

May be PMT aging?

Maybe yes, it is a more than 10 years old instrument.
Thanks for the answer!

Hi,
There are a few changes which you could utilise..
change liner/ septum, increase PFPD temperature (depending on what it is currently at) or you can also adjust the split valve so the tick tock is slightly off.

Liner/septum change is ok, for about 1 or 2 days long. So it would be kind of expensive solution. The temperature is on 310 celsius, i dont know what is the highest limit, but maybe i would give it a try. Split is OFF, so all of the possible injecatble sample amount is on the coloumn.
Thanks for the answer!

Hi,

Could you please reach out at sunny.singh@scioninstruments.com

Varian GC is now trading under the Scion brand. And pumpedupchemist works at Scion, UK

It would be good to get your details on our system for future support.

Thanks,
Sunny