- by /u/ngchHei, I'm working with an orbitrap Q exactive with Xcalibur 4.427. I can set microscans to >1 in the orbitrap tune program/tune file, but the Xcalibur method overwrites that to microscans = 1 whenever I start a run. The text version of the Xcalibur method also states microscans =1. But I cannot find a way to change this setting in the method (in Full ms – SIM mode). Can anyone help me find that setting? submitted by /u/ngch [link] [comments]
- by /u/Generated-Name-1715Hello, i want to drag my wiff2 data into the correct folder but cant because its supposed to be open in Clearcore2 Service.. because its currently running something else i cant just shutdown everything, but i need the data submitted by /u/Generated-Name-1715 [link] [comments]
- by /u/Ok_Struggle_3914These are the same quadrupoles, suppose to perform similarly. Maybe if it is Q1 scan, if there is flow in Q2, and Q3 is passed, the flow affects the mass accuracy of the Q1 scan ions? If it is Q3 scan, as the scan is after Q2, so the flow does not affect the mass accuracy? If so, maybe turn off the collision gas flow, the Q1 scan will have similar mass accuracy to the Q3 scan? and as the flow path length of Q1 scan is longer than Q3 scan, maybe the resolution is nitpickingly better? submitted by /u/Ok_Struggle_3914 […]
- by /u/EnvironmentalClue408Hello and welcome to my learning curve with our Triple Quad! (Agilent 7000D) My last lesson on here was to leave the collision cell flows on, even in standby, scan and SIM modes. Thread: https://www.reddit.com/r/massspectrometry/s/oV9fgxcrUm I tried it out and the response doubled. Wonderful! But: The ion pattern has changed. For example, a fatty acid methyl ester should have m/z 74 as the dominant ion. Now it's m/z 87, by far. Other compounds have similar effects (delta-Lactones give a very dominant 99 ion but now it's 71). Is there a way to optimize that? Or is it just a given […]
- by /u/Training_Pangolin177I asked the question before but didn't get a satisfactory answer. When turn on the HPLC pump module the degasser will not pass the initial test and will be in fault warning status, the fan on the power source can been seen attempt to start repeated but only to stop every time after momentarily started. However, if the power source to the degasser control board is first unplugged, and then turn on the HPLC pump module, followed by attaching the power source back on the degasser control board, the degasser can be brought online working without issue. Switching the degasser […]
- by /u/Intelligent_Bench734Hi! I’ve been trying to set up a method for lycopene using HPLC and Qtrap 5500+ but it is not looking good. Using ESI and direct infusion of solution I can see a peak at 537.6 which I think is lycopene but when I add a flow from LC via t split it just disappears. My stock solution is 1mg/ml in THF. I made working solutions 10ul of stock solution + 990ul of MeOH:H2O (9:1, 8:2 or 100% methanol) but different ratios didn’t change anything in my opinion. For LC phases I used water and methanol (10:90) (tried using additives […]
- by /u/userisanon_Hi! I’m new to GCMS and my instrument is down for 3 days now. After changing column, my supervisor saw a gap between the ms and gc. We are told by the lead analyst of gcms that it is ok to move it just by pushing it into the gc. However, it is making a loud noise when we turned it on. Any idea what went wrong? And what can we do about it? The one who’s about to check the instrument is not available until next week 🙁 submitted by /u/userisanon_ [link] [comments]
- by /u/oalkilaniHi all, this is my first time using an APCI probe. I’m trying to tune a highly lipophilic compound (β-carotene). My stock solution (1 mg/mL) was dissolved in THF with BHT. I prepared a 1 µg/mL sample by diluting the stock with MTBE, methanol, and water (70:20:10). I injected it directly from the syringe without any mobile phase running, and I kept the source temperature at 400 °C (also tried 300–450 °C). However, I couldn’t detect the expected mass (m/z 537 for [M+H]+). I’m using a Sciex 6500. Does anyone have suggestions or tips for tuning β-carotene with APCI? submitted […]
- by /u/PuzzleheadedFact560https://preview.redd.it/fytkq8n9ubuf1.jpg?width=4000&format=pjpg&auto=webp&s=e7c7dc3cc9a9e0d3a433b4167872331fe49d99e5 Hi everyone, I’m working on a Thermo Vanquish UHPLC coupled to an Orbitrap Eclipse Tribrid MS and I’d like advice about my recent blank run Column: Thermo Accucore C18+ (100 × 2.1 mm, 1.5 µm) Ion source: H-ESI Mobile phase: 90% water + 0.1%FA / 10% acetonitrile (HPLC grade, no additives) Flow rate: 0.2 mL/min MS acquisition: Full MS scan, positive polarity What I observed: Chromatogram (TIC): relatively flat baseline, with some noise but no distinct peaks (as expected for water blank). MS spectrum: background ions between m/z 150–250 and some higher clusters (likely solvent-related, plasticizers, or adducts). Pressure: […]
- by /u/WesternNational4283Does anyone have any experience or feedback on Agilents new Pro IQ mass spectrometer for use with LC? submitted by /u/WesternNational4283 [link] [comments]
- by /u/tritio07https://preview.redd.it/4nrf1tbgq6uf1.png?width=1600&format=png&auto=webp&s=7b44287d72130147a8b7d95eec3584fd72ddec80 Hello, I'm dealing with a contamination problem in my LC-MS/MS 6500+ system and I'm looking for insights and suggestions for a solution. The Problem: I ran a double gradient run (40 min run) to check for contamination in the column, mobile phase, or autosampler. The injection is a "blank" sample (pure solvent, H2O). The idea is that if the contamination were coming from the mobile phase, the carryover peaks from the first part of the run to the second part should have constant profiles and heights. What I observed: The contamination peaks decrease in size (intensity) in the second […]
- by /u/Possible_Intention72submitted by /u/Possible_Intention72 [link] [comments]
Mass spectrometry websites, social media, journal feeds, and other links and items of interest to the mass spectrometry community.
