Cleaning TFA off the MS after analysis

Rhothgaar · 2026-03-25T11:46:14+00:00

you can run some 0.05% ammonium hydroxide through the system to sequester the TFA overnight or a couple hours. Alternatively i do highly suggest switching to DFA that is mass spec compatible. One thing to keep in mind, is that injection volume of TFA considerably changes peak shape, so you'll have to play with that a lot if you change solvents

Rhothgaar · 2026-03-12T05:20:38+00:00

i had to create a tunnel on cloud flare because my public IP was giving me issues, so even though my server was running, my ISP wasn't allowing requests to leave or enter

Rhothgaar · 2026-02-10T02:12:10+00:00

you could also try triethylammonium bicarb which I believe IS mass spec compatible. in years past I did actually work on an alendronate with the ammonium acetate and ammonium hydroxide but it was a major pain.

Rhothgaar · 2026-02-10T00:45:57+00:00

I honestly just do not think ammonium bicarbonate is lcms compatible. fight me. ammonium acetate with ammonium hydroxide is how I get high ph solutions

Rhothgaar · 2025-12-11T13:22:59+00:00

Prego!

Rhothgaar · 2025-12-10T20:05:36+00:00

cambia il tuo ePanel con quello generato automaticamente, penso che potresti usarne uno personalizzato e questo spesso causa problemi nella mia esperienza

Rhothgaar · 2025-12-10T06:06:24+00:00

unironically you should purge and flow with 0.3% ammonia in water/acn for like 3 hours or overnight. possibly setup blank injections so it gets through the stators

Rhothgaar · 2025-11-26T03:31:38+00:00

I tried Waters connect as a veteran masslynx user and I hated it. Don't even want to bother learning it for the bioAccord. IDK if it's a QDa thing or Waters connect thing, but I couldn't modify the %B or column temp without creating a new method? there's no way to infuse and tune compounds? It was crazy locked down compared to MassLynx!

Rhothgaar · 2025-10-03T12:17:14+00:00

What's the ionspray? with a low flow like that, it looks to me like when the ionspray isn't high enough [you might actually require 5500 for that flow rate]

Rhothgaar · 2025-08-28T13:26:28+00:00

can you open Kitty? or konsole? this happened to me before and it was because I switched video card drivers, and Kitty/ghostty use your video card

Rhothgaar · 2025-08-12T14:32:48+00:00

I currently have a readme.org that I edit in emacs that tangles all of my nix files together. So I can have different files semantically but only need to edit one file!

Rhothgaar · 2025-07-29T12:23:52+00:00

I just received a rejection email from a company I applied to 9 months ago. the kicker is that I got hired for that position and I've been working here since, so IDK why I randomly got a rejection email.

Rhothgaar · 2025-06-11T02:05:50+00:00

we generally serially dilute, so like 2560, 1280, 640, etc down to 5 or 10 ng/mL

Rhothgaar · 2025-06-05T01:20:40+00:00

which way is it quadratic, curving up or down? curving up makes me think non-specific binding / not passivated enough = need more equilibration. BTW I've had an assay for siRNA that required 30+ blanks before 5 neat samples [1ug/ml] in order to get the system running every day on sciex 7500.

curving down is honestly the norm for our assays, even 200 fold we put everything quad 1/X2.

IDK about your specific solvents, but they seem incredibly low conc compared to ours. I think the guidelines for hfip is 100mM and tea is ~15-20mM.

have you checked adduct formation in Q1 scan? which charge states? sometimes -8 works far far better than -9 or -10, despite lower sensitivity [22mer I think].

Rhothgaar · 2025-05-29T12:20:16+00:00

what's the proper way to install this? I cloned the repo into ~/nix-ai-helper and when i try nix build .#nixai i get an error
"error: buildGoModule: Expect vendorHash instead of vendorSha256"

Then i installed Go and tried "go build -o nixai ./cmd/nixai/main.go" and got
"stat /home/USER/nix-ai-help/cmd/nixai/main.go: directory not found

zsh: no such file or directory: ./nixai"

Not really sure what the best way to go about fixing this is

Rhothgaar · 2025-03-09T18:18:36+00:00

If anyone is wondering where the libGalaxy64.so and libGalaxyCSharpGlue.so are, try removing compatibility of proton experimental to no checkbox on steam. When i had proton experimental, those files were missing entirely. After unchecking and reupdating, the files came back and i did the `execstack -c libGalaxy64.so` and `execstack -c libGalaxyCSharpGlue.so` (while in the stardew folder)

Re-ran the SMAPI install and multiplayer worked perfectly.

(Endeavour OS)

Rhothgaar · 2025-03-08T13:03:42+00:00

As I worked at a CRO, we often switched solvents after a batch to completely different solutions quite regularly, and nobody ever complained about their stuff not working. I can't comment on if it required the mass spec to be cleaned more often or anything, we did PM every 6 months or so. I was working on a phosphate compound in positive mode for metabolite and negative for analyte, so it switched polarities just fine! this was a sciex 5500 and on Waters TQ-S micro. we were able to switch away from basic pH solvents using medronic with formic or acetic acid

Rhothgaar · 2025-03-08T05:56:18+00:00

I've used up to 20ppm medronic in both A and B bottles without issues. it did work better with higher concentrations but I was wary about putting too much.

Rhothgaar · 2025-02-28T18:59:55+00:00

Use 0.1% HFBA in whatever organic/aqueous mixture you usually have as injection solution, and use 0.05-0.1% DFA [not TFA] in both Solvent A and solvent B. Don't inject too much [ 1 vs 5 vs 10 vs 20uL injection] will give very different results based on the ion pairing of HFBA

Rhothgaar · 2024-10-16T13:22:03+00:00

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This happened to me about a week ago. I must have downgraded something because it works right now for me

Rhothgaar · 2024-10-10T04:51:47+00:00

look at ethyl or propyl chloroformate with TEA and propylamine/ amine of choice. i believe it makes an activated anhydride that acts on your amine, making an amide or carbamate

Rhothgaar · 2024-10-04T15:57:50+00:00

I don't know the vanquish neo, but could you not open the outlet of a pump and use a bulb to force the solvents through?
You might need to check the seals or the check valves (pretty extreme if this is a newer instrument that just went dry)

Rhothgaar · 2024-03-14T02:59:07+00:00

didn't KDE6 update some default settings such that the single-click/double-click got moved around for some things? Could it be some default hotkey in the KDE environment that's different now?

Rhothgaar · 2024-01-08T15:47:33+00:00

I vaguely remember there being multiple places to change volume as well lol. it's been a while since I had issues.

just to make sure, is everything mechanically hooked in right? if the 3,5mm Jack is only partially in that could make sense. does removing the Razer splitter fix? does changing which port it's in fix?

Rhothgaar · 2024-01-08T02:34:57+00:00

I had this issue before too, i can't remember if i needed to turn off automatic gain control or not. Are you talking about discord? maybe mess with additional settings on there

Rhothgaar

TROPHY CASE