Droplet Assisted Inlet Ionization for Online Analysis of Airborne Nanoparticles.
Andrew J HoranMichael J ApsokarduMurray V JohnstonPublished in: Analytical chemistry (2016)
Airborne nanoparticles play a key role in climate effects as well as impacting human health. Their small mass and complex chemical composition represent significant challenges for analysis. This work introduces a new ionization method, droplet assisted inlet ionization (DAII), where aqueous droplets are produced from airborne nanoparticles. When these droplets enter the mass spectrometer through a heated inlet, rapid vaporization leads to the formation of molecular ions. The method is demonstrated with test aerosols consisting of polypropylene glycol (PPG), angiotensin II, bovine serum albumin, and the "thermometer" compound p-methoxybenzylpyridinium chloride. High-quality spectra were obtained from PPG particles down to 13 nm in diameter and sampled masses in the low pictogram range. These correspond to aerosol number and mass concentrations smaller than 1000 particles/cm3 and 100 ng/m3, respectively, and a time resolution on the order of seconds. Fragmentation of the thermometer ion using DAII was inlet temperature dependent and similar in magnitude to that observed with a conventional ESI source on the same instrument. DAII should be applicable to other types of aerosols including workplace aerosols and those produced for drug delivery by inhalation.
Keyphrases
- angiotensin ii
- water soluble
- particulate matter
- human health
- drug delivery
- risk assessment
- climate change
- gas chromatography
- angiotensin converting enzyme
- high throughput
- vascular smooth muscle cells
- single cell
- ms ms
- air pollution
- photodynamic therapy
- social media
- high resolution
- walled carbon nanotubes
- health information
- magnetic resonance
- computed tomography
- ionic liquid
- ultrasound guided
- density functional theory
- contrast enhanced
- tandem mass spectrometry
- optic nerve
- drug release