Title: Characterizing individual particles on tree leaves using computer automated scanning electron microscopy

Author: Johnson, D. L.; Nowak, D. J.; Jouraeva, V. A.

Year: 1999

Publication: Advances in Environmental Research. 2(4): 456-466.

Abstract: Leaves from twenty-three deciduous tree species and five conifer species were collected within a limited geographic range (1 km radius) and evaluated for possible application of scanning electron microscopy and X-ray microanalysis techniques of individual particle analysis (IPA). The goal was to identify tree species with leaves suitable for the automated characterization of aerosol particles deposited on their adaxial surfaces. Evaluations considered morphology of the leaf surface, ability of the preparations to withstand the high vacuum environment of the IPA equipment and potential for X-ray background interference. Eleven candidate species were tested under auto-run conditions (unattended analyses); the geometric mean particle size, mass median diameter and aerosol deposit mass loading are reported. Particle size, particle population per unit area and mass loading were log normally distributed. Variability in mass loading for the co-located species was about the same as within-leaf and between-leaf mass loading determined for linden leaves, and was inversely related to the area of leaf analyzed. Results for computer automated scanning electron microscopy of individual particles demonstrate the feasibility of monitoring particle assemblages directly on leaf surfaces.