Transcript
ACSM Advances
CACC Folks
Phil Croteau
January 20, 2021 Virtual AMS Users Meeting 2021 1
Outline
• TOF-ACSM Software
• Q-ACSM Mass Spec News
• Calibration kit work
• TOF-ACSM X
• “Answers” to submitted questions
January 20, 2021 Virtual AMS Users Meeting 2021 2
excluded from average
Acquility v2.3.9+
Moved from “Fast Switching” to “Time Resolved Evaporation”
Cube averaging for TRE mode enables manageable file size.
January 20, 2021 Virtual AMS Users Meeting 2021 3
Tofware 3
Leah will hold tutorial on Friday AM
Workflow 1
Workflow 2Divide analysis tasks into two “workflows”
1. Generate ‘diff stick’ mass spectra
2. Do AMS/ACSM analysis (species, etc.)January 20, 2021 Virtual AMS Users Meeting 2021 4
Q-ACSM – Pfeiffer will stop producing PrismaPlus and move to new PrismaPro
• Prototype PrimsaPro ACSM built up
• New electronics design in testing
• DAQ software in process
• Initial data look similar to PrismaPlus
• More analog and digital I/O
January 20, 2021 Virtual AMS Users Meeting 2021 5
Calibration kit development
Atomizer
Water trap
Dryer
DMA
CPC
ACSM
exhaust
Sample Pump
exhaust
ambient
ACSM filter-switching
• Switch between calibration and ambient (ACSM + SMPS) mode
• Ben Nault working on evaluation and prototype
January 20, 2021 Virtual AMS Users Meeting 2021 6
Compact kit via Aerosol Dynamics3D printed design via Dan Cziczo
Particle Counting – Aerosol Dynamics MAGIC CPC
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Moderated Aerosol Growth with Internal water Cycling
• Compact
• Water-based
• Ambient humidity is often enough water (no reservoir needed)
MAGIC compares well with a calibrated TSI 3776
January 20, 2021 Virtual AMS Users Meeting 2021 8
Ben Nault’s data
Particle size selection – Spider DMAStavros Amanatidis (CalTech) and Susanne Hering (ADI)
January 20, 2021 Virtual AMS Users Meeting 2021 9
Spider DMA Transfer Function
January 20, 2021 Virtual AMS Users Meeting 2021 10
Resolution ~3Dp max ~500nm
January 20, 2021 Virtual AMS Users Meeting 2021 11
300 nm NH4NO3
measured with AMS
from Spider and TSI DMAs
MAGIC Spider Measured Cooking Aerosol
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Q-ACSM Calibration comparing
TSI and Spider DMA
TOF-ACSM X
• Same footprint as TOF-ACSM• FTOF mass spectrometer
• Simplified/more robust HTOF• Resolution ~2000 m/dm• Same data system as TOF-ACSM• Can provide
• Explicit H:C, O:C• Improved NH4 with HR fitting
• ARI got this as Christmas present• Characterizing in lab now
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TOF-ACSM XResolution
(first measurements) No Vaporizer~2100 m/dm
With Vaporizer~1820 m/dm
Very quick tune done after vaporizer install – definitely room for
improvement
High resolution enables improved NH4
quantification
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High resolution enables improved NH4
quantification
Don’t believe absolute scale (analysis needs work) – just compare S/N
Sample HR Fits at m/z 43, 57
January 20, 2021 Virtual AMS Users Meeting 2021 18
Average Org Mass Spec
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Average*H:C = 1.52O:C = 0.45
*Not sure I’ve got calculation quite right yet
Q&A• To miniAMS-users: Which pressure do you have in the aerodynamic lens?
• For mAMS and TOF-ACSM, PM1 lens pressure should be ~1.75 mbar
• What is a suitable AB for ToF-ACSM ambient measurements and the typical response factor for that?• 1-4e5 ions/s, with an IE 100-500 ions/pg
• I would like to know the influence of m/z 44 artefacts in individual instruments, how it impact the results and the PMF analysis. • For our best on how to deal with m/z 44 artefacts see Freney et al., Aerosol Science and
Technology, 53:7, 830-842, DOI: 10.1080/02786826.2019.1608901
• ACSM Igor Updated Manual available?• No – we’re doing more Knowledge Articles to deal with specific questions, though
• Will acsm software be moved to Igor 7 or 8 (if not already)?• Tofware 3 is Igor 7/8 compatible• Acquility 2.3 is Igor 7 compatible• Q-ACSM works on Igor 6-8
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• Can the ACSM x resolve both CH2O+ and NO+ at m/z 30?
January 20, 2021 Virtual AMS Users Meeting 2021 21
Q&A
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