Okay so I’ve spoken with Restek and it seems like the nuts I have aren’t correct for the ferrules I’m using. Which is odd because I ordered them together. I switched back to the nuts that came with the system to see if that would work better. Here’s a photo of an unused ferrule and one that’s been compressed. The angle is clearly different, but I’m not convinced that the nuts are for the “compact” style ferrules either.
@TheGratefulPhil I may take you up on that call. Maybe instead of me beating my own head against the wall, you can give it a shot beating my head against the wall. Unfortunately, today is not GCMS day because I’ve been fixing a broken air particle counter and troubleshooting some lights that got made with the wrong drivers.
I also think there might be an issue with the pneumatics manifold/CI valve. The whole reason I’m fucking with these ferrules is that I’m still showing a bunch of water and a small amount of air, which goes away when I cap the column where it would go into the injector. On top of that though, I have a bunch of signal around 37 and 39 m/z which seems to increase when I open the CI valve. The system has been running for over a week straight so I don’t buy that it’s just residual methanol from cleaning the trap assembly.
These kinds of things happen… one time I ordered an Si column and got a completely different column type. I’d order another set - of nuts and ferrules, make sure they match the table for ID to OD - and make sure the size of the nut is appropriate for the connection location (5/16, I believe…)
For “residual” spikes - how big are the peaks? I’m going to assume that you don’t have 100% clean air where your machine is operating. I had a lab once that kept failing over and over again for methanol residuals on their calibration standards - turned out that they had around 150ppm of methanol in the air in the lab (hahaha, they now have way better HVAC and contamination controls…) - that was causing the issue the whole time.
So its possible everything is fine - but your seeing issues during injection or even within your closed sample from your environment. I run a blank just to make sure on this - and if that doesn’t make you feel comfortable you could always try using an EHS sniffer to collect a sample and have someone else check - or just get a methanol sensor and see what your ambient ppms look like.
Sid, earlier you mentioned rewiring to get correct power.
you might attach an appropriate SOLA power conditioner
on the front end of all electronics, and a separate copper
ground outside , and of course every buss or wire plug
should be carefully removed and reset…for fresh connection.
Yes a line reactor/power conditioner is probably a good idea. We just had a crazy power outage situation here where the city lost a phase and we burnt up some $30-40k in 3 phase motors. Fortunately, the MS was not a victim!
With the help of @cassin I am full steam ahead on this baby. Still fighting with the electron multiplier calibration a little bit but I’m actually getting something that looks like a chromatogram as of this afternoon!
Yes I’m currently retrofitting the ATS to provide phase loss protection to the whole building. As they say, I’m trying to ball on a budget
On another note, baby’s first chromatogram! The little peak is 3ul of methanol injected at a 5:1 injection ratio. Seems like a lot for not very much signal but then again I’m scanning up to 325 m/z
Brand new column, baked the shit out of the ion trap and the column. Verified no leaks with my little Restek sniffer but I’m still not convinced. I get some weird stuff and I have no idea how much noise is normal
Here’s one of some random rinsate I had lying around with no bother about dilution/concentration. I assume the primary peak around 14 minutes would be THC but I’ve not run my standards yet and it doesn’t match up too well with my library profile. Anyways, looks like tomorrow we play with standards!
This may be a you problem. I can see the pictures no issues. Maybe they are too big for your filter or something?
@SidViscous dude baseline is looking lovely. Digging those sharp peaks too. <3 Remember…any amount of noise is normal - as long as it is always consistent so you can disregard it. AND as long as your actual peak of interest has a strong signal outside of the noise. I mean sure… its always nice to have things nice a quiet and mostly smooth - but never expect zero, there’s always something hiding somewhere.
That one of the rinsate actually looks awesome to me. Clear solvent peak, and then not too much crap. Dialing in the RT a bit more with your standards will help with integration and those other ions will get left behind instead of it trying to quantify everything. We’ll get your calibration dialed in and your method integration dialed in and you won’t even see that stuff anymore.
As I posted that I got a tornado warning blasting through my phone. Maybe I’ll check out the window next time
Super cool to see @tokesandtinkery, @Killa12345, and @SidViscous getting up and moving on their analytical gear. Looking forward to throwing my hat in the ring and getting this qtrap moving over the next several months:
I really think all active members in this tread to be nominated for MOM !!
This tread althou not of interest to most
Is what this forum is all about
It s a pleasure reading from the side line and watch the developments
Big thumbs up to @SidViscous@Cassin@Chaboes@thesk8nmidget. @tokesandtinkery
Welcome to the party my friend! Used analytical equipment 4life!
@Roguelab thank you for the kind words. I certainly wouldn’t be posting pictures of chromatograms on here without the help of all these great people. I love this place
I’ve really enjoy following along and seeing other get value out of otherwise useless equipment. nothing is better than adding analytics for a discounted price.
I picked up 2x SRI GC’s a couple years ago and rebuilt them into one unit. After it was all said and done I had spent about $7,000 on a complete working system with TCD, PID, and FID detectors as well as a 12 chamber heated box. Hydrogen & zero grade air, regulators, syringe set, standards, new coil, etc.
It was a unique challenge as one I had never even seen one before and two, of the two units the one which had all the good stuff in it was used as a trainer it had seemed as everything was hooked up wrong and completely out of tune. Re-calibrating individual circuit boards can be fun… even more so when its not something you designed.
After that I rebuilt a Flash unit that had a blown lamp. Next up is the Micromass LCT mass spec.
So I officially have a problem lol. Since we’re actually getting chromatograms out of this thing and its been fairly painless, I just bought another GCMS and another spare GC for $1500 total. And one of these GCs has an ECD I think. I’m like an old Varian shit collector now.
Updates to follow on debugging this water issue and hopefully doing some calibration curves!
I’d order another set - of nuts and ferrules, make sure they match the table for ID to OD - and make sure the size of the nut is appropriate for the connection location (5/16, I believe…)
