Advertisement

response is low in varian GC3800 with 1200l MSMS

Discussions about GC and other "gas phase" separation techniques.

2 posts Page 1 of 1
Hi all,

I am working with the varian gc3800 and 1200l MSMS. Several weeks ago, I found the response of my chemicals (such as DDT, and d8-DDT) is becoming low. So I changed the liner, the septa, and cut the column, and also, cleaned the EI source. However, the response is still very low.

and there is another problem about the EI source. When I stalled the EI source back, the pressure of EI is between 10-50 mTorr. But the pressure is growing high after one injection. And now the pressure is about 6 Torr.

I have done the autotune. There is no leak, and no error.

I don't know what I can do.
Keep in mind the GC and/or MS is not always the problem.

I assume it's the response of a calibration solution. How old is this solution? When does it expire? Could it be contaminated?

That said i'm confused about the pressure in your MS. Is this chemical ionization or really standard electron impact (EI?)
2 posts Page 1 of 1

Who is online

In total there are 22 users online :: 0 registered, 0 hidden and 22 guests (based on users active over the past 5 minutes)
Most users ever online was 4374 on Fri Oct 03, 2025 12:41 am

Users browsing this forum: No registered users and 22 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry