Development of a pulsed radio frequency glow discharge for three-dimensional elemental surface imaging. 1. Application to biopolymer analysis.
Glow discharge optical emission spectrometry has cemented itself as an important surface elemental analysis technique in part because of its superb depth resolution (on the order of single nanometers). However, very few studies have explored the ability of the glow discharge to provide laterally resolved elemental information. In the present study, an end-on-viewed pulsed radio frequency glow discharge is coupled to a monochromatic imaging spectrometer to provide lateral surface imaging. The performance of the technique is demonstrated with etched copper circuits on fiber-glass substrates, and it is shown how several operating parameters including pressure, pulsed mode operation, and time-resolved detection affect the lateral surface resolution. In addition, because a pulsed radio frequency glow discharge offers elemental information on nonconducting samples, the technique is applied to the three-dimensional elemental analysis of proteins on blotting substrates. Several alternative sample types are also examined, including photographic film and glass.
Gamez
Gerardo
G
Department of Chemistry, Indiana University Bloomington, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA.
Ray
Steven J
SJ
Andrade
Francisco J
FJ
Webb
Michael R
MR
Hieftje
Gary M
GM
D001704:Biopolymers / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D055095:Optics and Photonics; D011506:Proteins / Q000032:analysis; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods; D013499:Surface Properties
D001704:Biopolymers; D011506:Proteins