Has anyone tried 10 mM AmAc:AmFo (~7:3 molar) as the additive for #LC-MS #lipidomics? Based on Cajka et al, seems like it would be a good compromise for fatty acids vs hydroxysterols to enable consistent RTs between polarities and fast polarity switching doi.org/10.3390/ijms...

Awesome #massspec teaching video for ion trapping--tangible/visible trapping in action: youtu.be link

I sometimes use Waters PrepMass column calculator for backpressures, volumes, flows, loads, and translating between column dimensions but it doesn't scale down to nanoflow. So I cloned and modified with LLM in a few shots: unitsaq.shinyapps.io/columncalcul... Original: www.waters.com/webassets/ot...

Nice work, demonstrating determination of omega positions in lipid acyls using only RT prediction! www.nature.com/articles/s41...

#TeamMassSpec Bench Tip: get a 5-kg scale with subgram accuracy for making >200 mL solutions. Faster and more accurate than a graduated cylinder. 1) Measure out solute mass 2) Calculate mass of solvent wrt solution and solvent density (in a reusable spreadsheet) 3) Add solvent mass, done!

Distilled rule of thumb for optimal Protein:Trypsin ratio vs Total Protein concentration in bottom-up #proteomics: Optimal protein:trypsin ≈ 0.1 * protein concentration (ng/uL) Aligns well with standard guidelines e.g. 50:1 at ~500 ng/uL Data from Table 5 in www.sciencedirect.com/science/arti...

Distilled rule of thumb for optimal Cosine cutoffs at various n matching MS2 fragments in #metabolomics ID: Cosine > 0.90 - 0.05*MMP Aligns well with ~80% at 3 matched fragments I learned before. From Fig4a here www.nature.com/articles/s41...

HILIC retention time stability solved?! www.sciencedirect.com/science/arti...