Online differentiation of mineral phase in aerosol particles by ion formation mechanism using a LAAP-TOF single-particle mass spectrometer

• Published in: Atmospheric measurement techniques Vol. 11; no. 1; pp. 195 - 213
• Main Authors: Marsden, Nicholas A, Flynn, Michael J, Allan, James D, Coe, Hugh
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 11.01.2018; Copernicus Publications
• Subjects: Aerosol particles; Aerosols; Alkali metals; Analysis; Atmospheric particulates; Atmospheric processes; Clay; Clay minerals; Composition; Crystal structure; Detection equipment; Differentiation; Dust; Dust particles; Dust storms; Ecosystems; Environmental changes; Feldspars; Illite; Illites; Internet; Ionization; Ions; Kaolinite; Labour; Lasers; Mass spectra; Mass spectrometry; Mass spectroscopy; Metals; Mineral particles; Mineralogy; Minerals; Molecular ions; Negative ions; Novels; Particle composition; Particle mass; Particulates; Physiochemistry; Scientific imaging; Silicate minerals; Silicates; Silicon compounds; Smectite; Smectites; Spectra; Spectroscopy; Temporal resolution; X-ray diffraction
• ISSN: 1867-8548; 1867-1381; 1867-8548
• DOI: 10.5194/amt-11-195-2018

Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS) is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI) followed by time-of-flight mass spectrometry (TOF-MS). Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.