r/massspectrometry

Hi everyone,

We are planning to purchase an Agilent LC/MS/MS system for PFAS testing and wanted to get some feedback from people with real experience.

Is the Agilent 6475 Triple Quadrupole LC/MS/MS strong enough for EPA PFAS methods such as 533, 537.1, and 1633?

Or is it worth spending significantly more money on the Agilent 6495D because of the higher sensitivity and performance?

We are trying to understand if the 6475 is enough for routine compliance work, or if the 6495D is a better long-term investment for PFAS testing.

Any feedback from labs running PFAS methods would be appreciated.

Thanks.

Hello all,

I am a junior undergrad who is working in a mass spec lab and trying to get better at MS/MS interpretation, part of the problem I am running into now is figuring out where a compound will fragment as well as understanding gas phase mechanisms. I didn't know if any of you with more experience had advice on how to better grasp this or if there were any books you would recommend. Happy to put in the time to learn any of this I just wasn't really sure where to begin. Any advice would be appreciated, thanks!

hey! long story short, I'm a undergrad student and I'm researching better ways to identify filamentous fungi on MALDI-TOF since they're much more difficult than bacteria or yeasts. I've run some tests and wanted the opinion of u guys how do the spectra looks, if it's good or too noisy, etc. since I don't understand what's considered to be good when you're analyzing proteome on a running metabolism instead of purified compounds.

ps.: don't mind the red identification, i already was like 99% sure the database wouldn't match since they were isolated from different environments.

https://preview.redd.it/b1cnbv3xfaah1.png?width=1920&format=png&auto=webp&s=5ac0a3ddd43459882ef36e22169e1e337377a2ab

https://preview.redd.it/vcumbv3xfaah1.png?width=1920&format=png&auto=webp&s=eefc2a67f610a575bce3787e6f1b0c2d79b303d2

https://preview.redd.it/zdxn1w3xfaah1.png?width=1920&format=png&auto=webp&s=6ddb6650e616d27a15122dee7fee0b2b02c90563

Does your method go over 700 bar (10kpsi)? Do you really need a >700 bar LC system?
I find very unnecessary how LC vendors do high brand marketing regarding how high their LC pressure can reach. I believe there are no many methods where going that high in pressure might be actually useful

A lot of our customers deal with lipid/carbohydrate-type separations and are often frustrated by dealing with molecules that lack a chromophore. They run a purification, check the UV trace, and... nothing. Meanwhile the target compound is probably sitting in a fraction somewhere. For those working with non-UV active compounds, they often consider RID vs ELSD.  

• Mobile Phase Compatibility (The Gradient Problem): RID is notoriously sensitive to temperature and mobile phase changes. Because of this, RID requires strictly isocratic runs. If you need a gradient to separate complex mixtures, RID is out. ELSD, on the other hand, excels here. Because it evaporates the mobile phase before detection, it easily handles gradients allowing for flexibility with solvent systems.  
• Peak Accuracy & Sensitivity: RID measures a bulk property of the solution, which means baseline drift is a constant battle, and sensitivity can be lacking for trace compounds. ELSD atomizes the effluent and detects the remaining solid particles via light scattering. This translates to a much flatter baseline, sharper peaks, and significantly higher sensitivity, allowing you to identify and isolate low-abundance fractions with much higher confidence.

  

RID works for some labs, but these customer experiences are why we incorporated ELSD into the BUCHI Pure Excellence Chromatography system, giving them a solution to find these compounds without sacrificing gradient flexibility or peak resolution. 

I’d love to benchmark this against how others are handling trickier separations right now. If you're running prep-scale or flash work, I'm curious:

• Are you using RID, ELSD, or something else? 
• What kinds of compounds are you purifying? 
• Any tricks for tracking "invisible" compounds without running endless TLC stains?

 

It seems the Agilent keep alive switch can be used to repalce some board without venting the instrument, I suppose that can be used to mannuall shut down the turbo pump and rougphing pump subsequently. Agilent doesn't sell the device to user.

Okay so mass spec doesn't have that big of an inventory, but maintaining it is never fun!

We built a free website called Lab Spend (it's old, we've been at this 7+ years) for those that are still entering chemical data into spreadsheets and struggling to keep inventory matched with SDS files.

New feature:

Upload photos of your chemical bottle labels and we'll extract the item name, CAS number, catalog number, supplier, size, and more. Batch uploads are supported, so you can process an entire shelf at once.

Upload your SDS and CoA documents and we extract the relevant data too — item name, GHS pictograms, lot numbers, and more — no copy-pasting required.

Finally, we match documents to the correct inventory item, so your bottle records, SDS, and CoA all stay linked without any manual cross-referencing.

Hello I recently got a hold of a Trace GC Ultra and a ISQ 7000 Single Quadrupole Mass Spec. I have been working the last few days to setup these devices to work with Xcalibur on a windows 10 control computer. I was able to get the Trace GC Ultra to connect without to much issue over serial, but have been unable to get the ISQ 7000 to connect. I dont know if it is incorrect drivers between Xcalibur, Foundation, and the ISQ or if im just missing a step. The device pumps down just fine and all of the front lights are solid green it just seems that I am missing something.

Any help would be appreciated thank you for your time.

The instrument loses communication with the controlling computer likely due to smart card and/or power source, so it cannot be vented with software. Does it work to vent by unplugging the turbo power and/or turbo control, either from the turbo control box or from the main power supply module? Does that let the turbo to spin down and then we can turn off the roughing pump or that also trigger the shutdown of the roughing pump? The intention is just to spin the turbo pump down and cut the roughing pump to avoid any damage to the turbos. Anyone has good idea on this? Thank you.

Hello,

We were graciously given a Thermo/Dionex PDA-3000. However, I can’t complete its configuration because it gets stuck at driver initialization.

We are technically using SII for Xcalibur 1.2 rather than a full Chromeleon installation. It will grab the serial number from the module, so I know there is at least some communication.

Here are things I have tried:
Restarting module
Removing stack but keeping just the detector
Plugging the USB from the detector to the computer directly
Going to SII for Xcalibur 1.5

Things I am going to try Monday:
Installing SII for Xcalibur on my laptop and trying
Try installing the detector on a colleague’s full Chromeleon 7.3 install

The firmware is 2.0.0, so I am wondering if maybe it is a firmware issue?

Can anyone chime in with experience or something i haven’t thought to try?

Thanks!

Has anyone switched from IP-MS to phosphoproteomics for a low-abundance phosphoprotein after antibody capture failures? Working with PBMCs/whole blood and trying to detect a specific phosphosite via PRM after IMAC enrichment. Curious whether the switch is worth it or if sensitivity becomes the new bottleneck.

Does anyone here have any experience with analysing glyphosate via direct injection methods without derivatizing? I have a couple of questions and would like to bounce some ideas off.