- by /u/Designer-Profit8333Help! I'm a complete noob… So the thing is I was not able to do proper equilibration… I switched the solvent system form ACN/water to MeOH/water… From the previous run the column condition was 70B… When I did the analysis now with MeOH, I set the solvent profile to 70B .. I was told I should have ramped the column condition first from 70B to 5B ACN before switching and started with 5B MeOH up to 70B… Was improper equilibration caused this pressure fluctuations? How should I deal with this? I already tried starting the conditioning at 5B MeOH … […]
- by /u/Designer-Profit8333For context, I am using a Shimadzu QTOF equipment… I am bothered by the very noisy baseline in MZmine where I will do most of my post run analysis… submitted by /u/Designer-Profit8333 [link] [comments]
- by /u/mage1413hi all, my transmission efficiency for sciex5500 is 18 percent. the cut off is 10 percent from the manual (reserpine Q1 to Q3). since the instrument is quite old, I'm thinking that 18 is too good to be true or is this normal? thank you submitted by /u/mage1413 [link] [comments]
- by /u/SalamanderMelodic374hello! i am not super familiar with MS so i apologize if this question is dumb. im a PhD student in microbiology, and a few months ago we used ESI Q-TOF to analyze lipid samples from bacteria. We recently gained access to the software needed to analyze MS2 data (positive ion mode), so was able to obtain the product ions from some MS1 precursors i was interested in. across the masses, there's a pattern of an abundant fragment of m/z 760-780 and then a second most abundant fragment of m/z 520-540. im trying to figure out what these fragmentation patterns […]
- by /u/penjjiiHey all, I’m looking to get into MS instrument development as it’s my main research interest going into grad school. I’d love to know who does this work in academia so I can consider applying for a PhD there this fall. I have worked with LC-MS for a few years in a research lab and my favorite part is learning about the instrument. What skills should I consider brushing up on/learning altogether before Fall 2027? What books and articles would you recommend I read to learn more about instrumentation/theory? I haven’t done that type of work before, so I’d really […]
- by /u/TonightHungry8520Hi everyone! I ran my data through SIRIUS. SIRIUS worked and exported a bunch of Excel files… but now I’m completely lost about how people actually go from these outputs to real metabolite IDs. My goal is that i only want annotated compounds that exist in HMDB (since it’s biological samples and I don’t care about synthetic/random database hits). I got the files exported which are in the image, but Right now it feels like I have results… but not something I can confidently say: “this feature = this metabolite”. If anyone has a practical workflow (like: open this file […]
- by /u/le_chantAs the title says, I’m looking to quantify aromatic amino acids in fermented food samples. Does anyone have any good recommendations on University cores or for-profit companies in the US for this? I’m looking for something relatively expedient (as university cores can sometimes be slow) but not crazy expensive per sample. I’ll also need sample prep. submitted by /u/le_chant [link] [comments]
- by /u/JACKHAGGETTsubmitted by /u/JACKHAGGETT [link] [comments]
- by /u/Training_Pangolin177At least the Gas 2 has problem. It is not flowing and the light for gas 2 on source board flash and then quit, but not gas 1, since both gas essentially come from the same source I suppose the gas 2 valve is bad. Is it safe to just diconnect the electric leads and gas tubes to the valves and replace the valve without vent the instrument? submitted by /u/Training_Pangolin177 [link] [comments]
- by /u/TonightHungry8520Hi all! I have experimental MS2 spectra and reference spectra that I wanna compare and present them, I just need to generate a clean mirror plot for my thesis/presentation experimental vs reference with matched peaks highlighted. Does anyone know a free, simple GUI or online tool where I can upload my sample MS2 spectra and the reference spectra and it will automatically mirror them just like the images shown. I have so many spectra and don’t want to do it manually it’s ugly and time consuming. Thank you in advance! 🙂 submitted by /u/TonightHungry8520 [link] [comments]
- by /u/Training_Pangolin177For example, if the source PCB needs to be replaced, is there a way to do it while maintaining the vacuum? How about other boards? It seems there is a way to do just that on a Agilent QTOF instrument, I saw a service engineer doing that with a device inserted to a port, even though I don't know exactly what is that all about. Thanks. submitted by /u/Training_Pangolin177 [link] [comments]
- by /u/No-Region-2187Hello Experts! We are developing a method for oligosaccharide profiling in our sample and by FLR-MS. We are doing a clean-up method by C18 pierce column before labeling and after the glycan release by PNGase F. Does anyone have any experience? please let me know if this workflow should work well? Activate the C18 (Pierce) spin column with 400 µL Activation Solution (50% ACN). Centrifuge according to manufacturer instructions and discard the flow-through. Equilibrate the column with 400 µL Equilibration/Wash Solution (0.5% TFA in 5% ACN). Centrifuge and discard the flow-through. Prepare the released glycan sample by adding Pierce Sample […]
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