Abstract:     Among the major challenges facing analytical science, quantitative trace analysis of atomic scale samples is among the most difficult and the most important.   The difficulty arises from the need to count the few atoms available in a particular sample with high - nearly unit efficiency, while discriminating against the vast excess of bulk atoms.   The importance arises from the needs of the semiconductor industry where shrinking device features ultimately will require the detection of single deep level trap atoms present at the ppt level.   In the future nanotechnology will also drive analysis toward this atom counting limit.   Trace elemental and isotopic analysis of micron sized SiC grains culled from the Murchison meteorite demonstrate the limits and power of new trace analytical methods developed with high useful yields and high discrimination for mass spectrometric analysis.   These microcrystals condensed in stellar outflows and have remained unchanged during the formation of our solar system.   The geminate isotopic record contained in this "stardust" gives important clues into the mechanisms of stellar nucleosynthesis.

Biography:     Dr. Michael Pellin received his B.S. degree in Chemistry from Northwestern University in 1974 and his Ph.D. degree in physical chemistry from the University of Illinois (Champaign) in 1978.   Dr. Pellin has been a scientist at Argonne National Laboratory since 1978.   Currently he is a Senior Scientist and the Associate Division Director for the Materials Science Division.   His research is directed at Surface Chemistry and includes the development of Resonant Photo-Ionization Mass Spectrometers.   These instruments are the most sensitive in the world for trace analysis of small samples.   His research has resulted in 11 patents and over 150 publications.   His work has resulted in an Energy 100 award, a University of Chicago Distinguished Performance Award, a Special Award for Excellence in Technology Transfer, and an IR-100 award.