ULTRASPATIALLY-RESOLVED SYNCHROTRON INFRARED MICROSPECTROSCOPY OF PLANT-TISSUE IN-SITU

Routine use of 6 mu m or 12 mu m apertures with synchrotron microspect roscopy provide good spectra without excessive co-addition of scans. 1 00% mapping by stepping in pixel sized increments reveals chemical het erogeneity within cellular dimensions. The brightness of the synchrotr on source and the absence of thermal noise compared to a conventional thermal (globar) source yields favorable signal-to-noise operation. Th e nondivergent characteristics of the source result in minimal loss of radiation at the aperture, hence, spatial resolution approaches the d iffraction limit. Details of cellular dimensions are then localized wi thin any maps produced and individual spectra obtained from adjacent p ixels clearly shows the striking difference in chemistry even within a microscopic vicinity. In this report the mapping of plant tissue with the synchrotron is contrasted to previous lower spatial resolution ma pping experiments done with the globar on similar materials using inte rpolation between separated sampling spots and larger apertures.