Single-pollen analysis by laser-induced breakdown spectroscopy and Raman microscopy.
The application of laser-induced breakdown spectroscopy to the analysis of single biological microparticles (bioaerosols) is described, exemplified here for a range of pollens. Spectra were recorded by exposure of the pollen to a single laser pulse from a Nd:YAG laser (lambda = 1064 nm, Ep approximately 30 mJ). The intensities of the single-pulse laser-induced breakdown spectra fluctuated dramatically, but an internal signal calibration procedure was applied that referenced elemental line intensities to the carbon matrix of the sample (represented by molecular bands of CN and C2). This procedure allowed us to determine relative element concentration distributions for the different types of pollen. These pollens exhibited some distinct concentration variations, for both major and minor (trace) elements in the biomatrix, through which ultimately individual pollens might be identified and classified. The same pollen samples were also analyzed by Raman microscopy, which provided molecular compositional data (even with spatial resolution). These data allowed us to distinguish between biological and nonbiological specimens and to obtain additional classification information for the various pollen families, complementing the laser-induced breakdown spectroscopy measurement data.
Department of Physics, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
Ana R
AR
Boyain-Goitia
David C S
DC
Beddows
Ben C
BC
Griffiths
Helmut H
HH
Telle
D000336:Aerosols / Q000032:analysis* / Q000737:chemistry*; D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D005240:Feasibility Studies; D006368:Helianthus / Q000737:chemistry; D006358:Hot Temperature; D007834:Lasers; D027762:Lilium / Q000737:chemistry / Q000145:classification; D008863:Microspheres; D010316:Particle Size; D006109:Poaceae / Q000737:chemistry; D011058:Pollen / Q000737:chemistry* / Q000145:classification*; D013057:Spectrum Analysis / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods
D000336:Aerosols; D000393:Air Pollutants