Hamish Stewart's Avatar

Hamish Stewart

@hamishs

Analyzer evangelist and mass spectrometry enjoyer. Read about the Astral analyzer: https://pubs.acs.org/doi/10.1021/acs.analchem.3c02856

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15.11.2024
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Latest posts by Hamish Stewart @hamishs

Hardest part is that she doesn't know what a scam these cards are.

06.03.2026 22:31 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Were there many reasons given not to fill one up like a foie gras goose?

06.03.2026 22:25 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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a close up of a cat 's face with its mouth open on a pink surface . ALT: a close up of a cat 's face with its mouth open on a pink surface .
06.03.2026 22:13 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Wouldn't say any of it is really dumb, and they're all questions one might ask oneself.

The next step for it might be how to discard an idea. For example, computational burden of real time analysis (and rescoring?), dynamic range on mega-multiplexing, electrodynamic signals on ToF mass range etc.

05.03.2026 19:52 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

That may be too much to ask! The really advanced algorithms are a bit too severe for millisecond response times.

But maybe room for more general predictions...

04.03.2026 23:11 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Indeed the automated analysis is very detached from both the priorities and even (what I would consider) the biggest problems.

04.03.2026 23:03 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

Get ready for the bombardment of crazy requests and ideas..!

04.03.2026 22:57 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Good news!

04.03.2026 21:50 ๐Ÿ‘ 3 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

I like the thought that an LLM might come up with, and highlight, the sort of niche connections a serious expert might occasionally make in the shower.

Can it though. How does one ask?

04.03.2026 21:09 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Any interest in taking multiple scans per precursor at different mass ranges, or are losses more than acceptable? ๐Ÿ˜€

04.03.2026 20:59 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Works on multiple levels! ๐Ÿ˜„

04.03.2026 12:28 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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25.02.2026 23:28 ๐Ÿ‘ 7 ๐Ÿ” 4 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Aye, it all derives from the 2022 application. There's some mechanism behind claims in these additional documents.

02.03.2026 20:02 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Number of ions imposes a limit, but things can always be worse.

For context, label free quan peptide-level CV is ~10% typically, if I recall correctly.

01.03.2026 20:10 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
The mass range of tandem mass spectra can be categorized into three main regions. For glycopeptides, the lower mass range contains mainly oxonium ions, the middle range contains mainly peptide fragments, and the high range contains charge-reduced fragments. All regions contain valuable fragment ion information, but they can only be simultaneously accessed by breaking the 5โ€“10โ€“15 rule.

The mass range of tandem mass spectra can be categorized into three main regions. For glycopeptides, the lower mass range contains mainly oxonium ions, the middle range contains mainly peptide fragments, and the high range contains charge-reduced fragments. All regions contain valuable fragment ion information, but they can only be simultaneously accessed by breaking the 5โ€“10โ€“15 rule.

MS/MS scan range can be an afterthought that doesn't receive attention in method design, but improper settings can affect experimental outcomes. This is especially true in glycoproteomics.

A #glycotime thread about a new #JASMS paper on this idea from @riley-research.bsky.social

1/10

27.02.2026 19:40 ๐Ÿ‘ 20 ๐Ÿ” 8 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

Alas no! We have a regime of industrial design guidance to make every product harmonised, user friendly, intuitive... and a white box with a black front and a blue pulsing light.

The box looks much better, but the lighting is a devastating loss.

27.02.2026 23:00 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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Finally released the preprint covering TMT HR mode for the Orbitrap Astral Zoom mass spectrometer. Here, multi-pass MS/MS measurements grant us sufficient resolution to quantify TMT reporter ions even to 35-plex, greatly increasing analytical throughput.

www.biorxiv.org/content/10.6...

27.02.2026 14:12 ๐Ÿ‘ 7 ๐Ÿ” 2 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Sounds reasonable to me, and this need to reduce co-isolation pulls us to long gradients, good chromatography etc.

Idle speculation: Perhaps in Astral data, as many PSMs are filtered out from quantification (but there are a lot of PSMs), strong interferences may be preferentially filtered.

27.02.2026 13:08 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

I would expect 15 ions in Astral gives better reproducibility, if only because it's much further above the noise line. I think it shouldn't be hard to dig up CVs.

But indeed, on the higher load (non degraded HeLa sample), it averages >100 ions per peak.

27.02.2026 12:53 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

In defense of MS2 TMT, use of FAIMS and advances in quadrupoles allow ~90% interference free index, similar to MS3 prior to real time search no?

I'd show RTS MS3 if we'd kept the original plan and built the Orbitrap Astral MS with an ion trap, but we'd never have finished the project.

27.02.2026 11:50 ๐Ÿ‘ 4 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

Timing here is that this study combines data from multiple groups, a lot of it presented last ASMS, but the task of aggregating results and writing up wasn't owned by anyone. Took me a little while to confirm.

27.02.2026 10:38 ๐Ÿ‘ 4 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Curious! I've seen comparisons to mass spec (albeit not in agreement, while MS vs MS is ok), but it should be no problem to assess via controlled samples.

I know people for whom such investigation, with mass spectrometers, is much of their jobs.

02.02.2026 20:00 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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02.02.2026 19:05 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Are there not standard-based quantitative, multi-proteome or matrix matched serial dilution experiments?

The sort of thing that's very standard in assessing mass spectrometers?

02.02.2026 18:51 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Always enjoy a rare multi-reflection ToF publication. Fills in some gaps.

27.01.2026 22:25 ๐Ÿ‘ 4 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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[ASAP] Faces of Mass Spectrometry/Khatereh Motamedchaboki Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00430

(JASMS) [ASAP] Faces of Mass Spectrometry/Khatereh Motamedchaboki: Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00430 (RSS) #MassSpecRSS #JASMS

10.01.2026 17:06 ๐Ÿ‘ 2 ๐Ÿ” 2 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Big evaluation of our Orbitrap Astral Zoom mass spectrometer by the Olsen group, now peer reviewed, published and open access.

www.sciencedirect.com/science/arti...

10.01.2026 13:34 ๐Ÿ‘ 14 ๐Ÿ” 4 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

I recall Waters had a guide for cleaning their Stepwave, which isn't too far off, and had a mixture of soft cleaning agents. No idea how effective it is though.

06.01.2026 16:29 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Ooh thanks! a really mild mixture. I wondered how successful it would be.

I see ion funnels sometimes caked in material, with acidic detergent being pretty good for removing it, though not an option for soldered parts.

06.01.2026 00:24 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Nice! How do you usually go about cleaning ion funnels that have soldered pcb parts, if you dont mind my asking?

05.01.2026 20:52 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0