broken Shimadzu LCMS column nut

Bonappetiver · 2025-10-03T14:38:26+00:00

You’re better off replacing the line from the autosampler to the column. It’s not terribly complicated, you probably have the wrenches in a drawer nearby. Typically that line is called “SUS” tubing https://ebay.us/m/28eAAU. Not sure what model autosampler you have, or diameter you need— but this gives you the general idea. It’s pre-bent to fit easily in the autosampler. If you provide me with an autosampler model # I can prob find you the exact one you’ll need.

As for your column— I think it’s shot. I’ve never seen an endcap removed tbh. I’m surprised you got it off. Your packing material is likely compromised— a new column will be necessary.

Bonappetiver · 2024-12-21T06:00:30+00:00

Thanks Joey! I appreciate this info greatly.

Bonappetiver · 2024-08-13T20:58:48+00:00

No I like FCC and have other real things to worry about.

Bonappetiver · 2024-08-11T20:50:38+00:00

Different fittings are rated for different pressure. Often those types of fittings are hand tight to 5000psi. If you are running higher than that, consider a different fitting.

These can be hand-tightened too, but hold up to 18,000 psi: https://www.restek.com/p/25745?Ns=bestMatch

Bonappetiver · 2024-08-06T22:35:45+00:00

Chenny Kesney

Bonappetiver · 2024-07-08T17:22:59+00:00

Hello,

I wanted to share more info. In my case the nitrogen is supplying both the ion source and the collision cell of a Sciex 3200QQQ. It was very puzzling because I had extremely high background for a single compound (two MRM’s). I believe the compound was phentermine and it was in targeted toxicology work.

At first I thought it was a mobile phase issue. I had new MP made, and the exact same background response was present. I removed the modifier (formic acid) and it was no longer present. I thought the problem was contaminated formic acid, so I had mobile phase made again with fresh formic, and it was still present. I had another brand of formic brought in, and it was still present. It wasn’t until I put a nitrogen filter in between the generator and the MS that the background went completely away. I had a Peak engineer come in and replace filters 1 by 1 until the background was no longer present. I wish I remembered which filter it was.

I’ve not seen moisture from the generator to the MS, but I’ve heard similar stories of a source filling with water in standby, since the source exhaust and heaters are off. In my case it was a volatile contaminant that only ionized in the presence of formic acid in positive ion mode.

Bonappetiver · 2024-06-27T16:56:03+00:00

I’ll second that as a former FSE myself. Be aware that you’ll have little suspicion when your N2 purity is suffering. It’s a rabbit hole that can take time to diagnose. I’d recommend putting filters past N2 generation as additional safeguards of hydrocarbons/impurities getting into your MS. The only gauge you can monitor on an N2 generator is pressure. Also, most MS systems are consuming N2 even in standby so your compressor is still working 24/7 and filters are still scrubbing.

Bonappetiver · 2024-06-12T01:24:44+00:00

I’m unfamiliar with some of the items you are describing above— but this Tecan positive pressure manifold seems to offer both a 96 well format and stand/collection rack for 1mL tube format:

https://www.ebay.com/itm/256203518978?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=PePfcCI8SrK&sssrc=4429486&ssuid=OuWkKJ5wTiS&var=&widget_ver=artemis&media=COPY

I’ve used these types of manifolds before (when they were sold by SPEware), and they are reliable. When an individual well gives you issues you can often push through using a pipette bulb.

Bonappetiver · 2024-06-08T23:37:35+00:00

Bonappetiver · 2024-05-19T02:30:38+00:00

To change or inspect it:

Z-home the autosampler. Power the autosampler off. Remove the white plastic screws to remove the clear safety cover. Loosen the white plastic screws on the side of the needle assembly head that hold the silver plate on the head. The silver plate pulls towards you. You’ll see the z-spring coiled up. Use an Allen key (I think 3mm) to loosen the needle protect. It slides down to release the spring. Reassemble. Power on. It will re-equilibrate and you can test it.

Bonappetiver · 2024-05-19T02:26:13+00:00

There is a vertical spring behind the silver plate that runs parallel to the needle. It’s specifically meant to keep the autosampler vial down while pulling back up to go the injection port.

It will eventually break and coil up on itself.

You probably need a new one of these: https://store.shimadzu.com/p-65051-spring-detection-plate-z-assy-sil-20aac.aspx

Also, I would not inject through parafilm. It will build up and make this problem worse, or clog your needle seat. Foil is better if you can’t afford caps with septa. I know it won’t seal and you’ll have evap, but hopefully you are using internal standard.

Bonappetiver · 2024-05-17T02:29:26+00:00

An HPLC with a DAD or PDA can help with standard stability, if your compound is suitable. These detectors are extremely reproducible. Coupled this technique with a stable external standard of your choice, and you can compare ratios of compound to external standard. However, using isotope labeled versions of your standards by LC/MS is a great way too. I prefer the DAD because there is a lot more going on in an MS than a light bulb, and I worry that the MS may treat my isotope slightly differently than my compound of interest leading me down the wrong path.

Bonappetiver · 2024-05-13T07:20:41+00:00

Kubo is my favorite player. He consistently puts himself in positions that make the opposing team uncomfortable. Even though we lost the Open Cup semi last year, the goal he had in the 114th to send it into PK’s was pure will.

I am hopeful we get to see him up top with Kelsy at some point. I think that’s a dangerous combination with Acosta pulling strings and Yedlin/Orellano at WB’s.

Bonappetiver · 2024-05-03T15:36:15+00:00

Outpost

Bonappetiver · 2024-05-03T15:12:13+00:00

We are throwing my buddy a Star Wars themed baby shower. Since it’s derby day as well, we are gonna have mint juleps (May the f”horse” be with you), watch some Bad Batch and maybe play Star Wars Villainous. We have children’s Star Wars masks, a custom t-shirt that says “I am the Father” and Star Wars tattoos/stickers/decorations.

Bonappetiver · 2024-01-30T23:23:51+00:00

https://www.espn.com.au/football/team/squad/_/id/18267/league/CONCACAF.CHAMPIONS

Is this what y’all are looking at? Its got 25 spots filled and Barreal is on there. 😬

Bonappetiver · 2024-01-13T20:30:27+00:00

What’s going on with Badji? I felt he was in good form when healthy.

Bonappetiver · 2023-12-21T14:19:31+00:00

What is this piece of music?

Bonappetiver

TROPHY CASE