@unitsaq.bsky.social
Interested in LC-MS -omics (proteomics, metabolomics, lipidomics, exposomics).
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...
Original:
www.waters.com/webassets/ot...
PrepMass Column Comparator (Scaled to μL/min and μg)
unitsaq.shinyapps.io
September 18, 2025 at 7:06 PM
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...
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...
Computationally unmasking each fatty acyl C=C position in complex lipids by routine LC-MS/MS lipidomics - Nature Communications
Physiologically relevant omega-positions of double bonds in fatty acyls in complex lipids can now only be identified with specialized instrumentation. Here, the authors present a computational approac...
www.nature.com
August 14, 2025 at 4:24 AM
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!
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!
August 6, 2025 at 1:32 AM
#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!
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...
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...
July 28, 2025 at 6:14 PM
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...
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...
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...
July 24, 2025 at 7:49 PM
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...
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...
Solving the retention time repeatability problem of hydrophilic interaction liquid chromatography
Hydrophilic interaction (liquid) chromatography (HILIC) has become the first choice LC mode for the separation of hydrophilic analytes. Numerous studi…
www.sciencedirect.com
March 4, 2025 at 5:45 PM
HILIC retention time stability solved?! www.sciencedirect.com/science/arti...