MSD-Problems

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

5 posts Page 1 of 1
Hey everybody,

i have a massiv problem wih my msd and it even affects the tune (ADC Readings) and the mass spectrum.
As I am no native, i will attach some pictures to this, as it is really hard to explain. But it seems to be electronic? (last picture, which shows he regularity of the "ions")

Things I did do without any solution:
cleaning the source, checking all cables, checking the multiplier connection, changing the filaments and insulators of repeller, turning the HED off (to check if this is the problem)

Please help me and & thx in advance!

Image

Image

Image

Image

Image
The abundances in the Manual Tune picture are almost nothing. Is it possible that your PFTBA vial is empty? If you scan for water and nitrogen, what does that look like?

Does everything look the same when you use the other filament?
When we had the fleacomb or lawn problem with spectra and the jagged looking random chromatogram, the Agilent folks indicated to me that it could be the multiplier or the HED. I was not given the option of turning off the HED to trouble shoot but we ended up replacing the HED and multiplier (as the HED does not come without a mulitiplier) and it fixed the problem.
Hey there!
Thank you for your answers.
To answer your questions or make statements to your advices:
1. PFTBA is not empty, but the abundances may be altered by nitrogen & water in the source. Much likely this is caused by venting MS quite often these days.

2. Filaments have already been changed and it looks similar for both, old and new.

When we had the fleacomb or lawn problem with spectra and the jagged looking random chromatogram, the Agilent folks indicated to me that it could be the multiplier or the HED. I was not given the option of turning off the HED to trouble shoot but we ended up replacing the HED and multiplier (as the HED does not come without a mulitiplier) and it fixed the problem.


The Agilent customer care indicated to me that it would be the Log Amplifier and made an offer, which was pretty much about changing everything inside the MSD.

Well we ordered one ourselves and changed the Log Amplfier as it is just one cable and 3 screws. Long story short it didnt help, but the device is still alive.

But I would agree on the HED, since it is most likely regarding the problems.
Which model Agilent is this one. Since you say the HED and multiplier are the same part I assume late 5975 or the 5977.

The HED is actually the stainless steel "button" 90 degrees offset from the detector, which can be removed and cleaned on the 5973 and early 5975, and I think you can also do it on the later 5975 and 5977 models also.

We just had a problem with our early 5975 and it turned out to be the feedthrough for the HED power. The socket that has the wire that looks like a sparkplug wire attached. The pin in the socket was broken off and stuck in the wire, and was making intermittent contact until it finally made no contact at all. It is easy to replace the socket part, just unscrews and has o-ring seal.
The past is there to guide us into the future, not to dwell in.
5 posts Page 1 of 1

Who is online

In total there are 14 users online :: 1 registered, 0 hidden and 13 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: Baidu [Spider] and 13 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, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry