Single particle analysis of suspended soil dust from Southern California

Single particle analysis of soil dust has been performed using aerosol time -of-flight mass spectrometry. The presence of crustal elements is observed in the mass spectra of individual particles. Aluminum and iron constitute t he two most commonly detected cations. Other common cations observed in the mass spectra of soil particles include sodium, magnesium, potassium, calci um, titanium, and barium, and also lithium and lanthanide oxides which are not detectable by conventional techniques such as X-ray fluorescence. Silic ates make up the bulk of detected anions, although the presence of phosphat e is also observed. Characteristic peaks in both the positive and negative ion mass spectra enable us to identify individual dust particles in atmosph eric samples and track chemically distinct dust particles in the atmosphere with a temporal resolution of 15 min using aerosol time-of-flight mass spe ctrometry. (C) 2000 Elsevier Science Ltd. All rights reserved.