Aerodyne - Aerosol Mass Spectrometer System (AMS)
The Aerodyne aerosol mass spectrometer (AMS) is the only currently available instrument capable of providing quantitative size and chemical mass loading information in real-time for non-refractory sub-micron aerosol particles. The AMS couples size-resolved particle sampling and mass spectrometric techniques into a single real-time measurement system. The Aerodyne AMS has been deployed world-wide at fixed sites, and on mobile laboratory, ship and aircraft platforms. Over 100 instruments are in use in industrial, academic and government laboratories.
- Measurement of ambient atmospheric aerosol mass loadings and size distributions for environmental monitoring.
- Emissions characterization of combustion sources. Direct determination of OC emissions indices with simultaneous measurement of plume CO2.
- Eddy correlation flux measurements of aerosol sulfate, nitrate, ammonium, and organic species dry deposition fluxes.
- High time-resolution mapping of fine aerosol properties from affordable mobile (van, small aircraft) platforms.
- Diagnostic for laboratory aerosol sources, flow reactors or aerosol chambers for aerosol physics and chemistry experiments.
- Analysis of chemical composition as a function of particle size for aerosol delivery systems such as metered dose inhalers. High time-resolution allows measurements on a puff-by-puff basis, eliminating need for time-consuming impactor analyses.
- Single particle chemical analysis with light scattering module and time-of-flight mass spectrometer.
- Mass spectrometric detection combined with particle time-of-flight provides information on particle aerodynamic diameter and aerosol composition in a single measurement.
- Quantitative chemical analysis by thermal vaporization and electron impact ionization mass spectrometry. Particle vaporization temperature adjustable from 200 C to 900 C. Laser-induced incandescence vaporization of black carbon under development.
- Real-time, quantitative size resolved aerosol mass measurement for non-refractory fine particulate matter (40 nm to ~1 µm). New inlets to transmit smaller and larger particle size ranges under development.
- Direct sampling of ambient aerosols; no filters or off-line chemical analysis necessary.
- Fast measurement (1 – 10 sec) of particle size distributions and non-refractory chemical composition. Maximum data collection rate of 100 Hz.
Two versions of the Aerodyne AMS are available. The Compact Time-of-Flight AMS (C-ToF-AMS) incorporates a high-performance, compact time-of-flight mass spectrometer and enables continuous monitoring of the mass spectra (1-800 m/z) of all sampled particles at rates as fast as 80 kHz. The detection limit for the C-ToF-AMS is the lowest of the two versions. The High-Resolution ToF AMS (HR-ToF-AMS) also enables continuous acquisition of complete mass spectra of individual particles, and enables the resolution of distinct chemical species based on mass defect. Algorithms are being developed which allow elemental analysis of HR-ToF-AMS data. The properties of the two versions are summarized in the following table.
- Size: Approximately 41'W x 24'D x 53'H
- Weight: Approximately 170 kg
- Power: Approximately 600 Watts. Universal power 110VAC/60Hz or 220VAC/50Hz. Vacuum system fully operational on 24 VDC.
- Computer: Current systems are shipped with rack a mounted computer, PIII 3GHz, Intel CoreTM 2 Duo Processor, 512M SDRAM, 160G hard drive, CD-RW, floppy, 10/100 Ethernet port, 8 USB ports, 1 serial port. Flat screen monitor 15” XGA.
- Packaging: Shipped in one reusable container. Total shipping weight ~280 kg
Light Scattering Module provides additional information for larger particles (>200nm), particularly for large refractory (dust) particles with low non-refractory coatings. Light scattering analysis also can provide information on particle density and distinguish internal/external mixtures.
Negative Ion Detection Option for ToF-AMS (via electron attachment) selectively detects stable anion species, such as sulfate, nitrate and carboxylic acids. Sensitivity is 1000 lower than electron impact (EI). Switchable with standard EI.M
Relative Humidity/Temperature/Pressure probes allow the user to measure ambient relative humidity, temperature and pressure at sampling inlet, with all measurements fully integrated into the data acquisition system.
Beam Width Probe allows measurement of particle shape by measuring the divergence of the particle beam.
Service/Support Contract (3 years) includes spare parts (extra filaments and electron multiplier) and up to two weeks of on-site support. Parts and support are interchangeable, as needed, based on advance payment of fee. Parts will usually be shipped overnight.
The TAG-AMS project is an collaborative development project between ARI, Professor Allen Goldstien at UC Berkerely and Susan Herring of Aerosol Dynamics, Inc.
The TAG-AMS combines the advantages of the Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) (Canagaratna et al. 2007) measuring size distribution and mass loading for ambient aerosol and the Thermal desorption Aerosol Gas chromatograph (TAG) (Williams et al., 2006) instrument providing hourly measurements of speciated organic compounds. The combined TAG-AMS instrument shares the same electron impact ion source and HR-ToF-MS for analysis of the atmospheric aerosol constituents. While atmospheric aerosols are measured using standard HR-ToF-AMS measurements providing mass spectral analysis of the total organic aerosol (AMS), the same aerosol sample is collected simultaneously in the integrated collection and thermal desorption (CTD) cell of the TAG instrument. The collected aerosol sample is subsequently desorbed from the CTD cell, chromatographically separated, and introduced into the AMS electron impact ionization region for analysis. The combination of hourly time resolved TAG measurements with the complimentary AMS measurements provides mass spectral analysis of the total organic aerosol (AMS) and a detailed molecular level analysis (TAG).
The TAG-AMS instrument was recently deployed during the California at the Nexus between Air Quality and Climate Change (CalNex) Experiment 2010 in Pasadena successfuly demonstrating this new combined technology. Current developments are focused at miniaturizing the GC column, inproving the sampling interface between the AMS and the the GC column and devloping software analysis tools to efficiently process the TAG-AMS data sets.
The Soot Particle Aerosol Mass Spectrometer (SP-AMS) makes real-time, in situ measurements of black carbon containing particles. The SP-AMS instrument combines the technologies from two proven, commercial aerosol instruments: Aerodyne’s Aerosol Mass Spectrometer (AMS) (Canagaratna et al., Mass. Spec. Rev., 26, 185-222, 2007) for quantitive aerosol mass loadings and Droplet Measurement Technologies’ Single Particle Soot Photometer (SP2) (Baumgardner et al., GRL, 31, LO6117, doi:10.10129/2003GL018883, 2004) for black carbon. The SP-AMS uses laser-induced incandescence of absorbing soot particles to vaporize both the coatings and elemental carbon cores within the ionization region of the AMS, providing a unique and selective method for measuring the mass of the refractory carbon cores (i.e., black carbon mass), the mass and chemical composition of any coating material (e.g,. organics, sulfates, nitrates, etc.), and particle size and morphology.
The SP-AMS has been deployed in several field campaigns for measurements of ambient aerosol (Queens, NY, 2009), biomass burning plumes (FLAME III, 2009) and ship plumes (CalNex 2010).