Optical Emission Spectroscopy of Combined Laser Ablation-Hollow Cathode Glow Discharge Plasma Source

Abstract

The combination of laser ablation and glow discharge (LA-GD) as a spectroscopic source for elemental analysis is an increasing field of study in recent years. This is due to the fact that the laser ablation-glow discharge provides a more stable and reproducible spectra of the sample in comparison with the transient laser ablation. An important advantage of the laser ablation-glow discharge technique is the possibility for independent control of the processes of sample introduction and sample excitation. The combination of laser ablation and glow discharge is also capable of sampling non-conducting or low-sputtering-yield materials which for stand-alone glow discharge usually requires preliminary sample preparation procedures or use of pulsed power supply. Exploiting the characteristics of this technique has resulted in increase in sensitivity and limit of detection (Tereszchuk K, Vadillo J, Lazerna J Appl Surf Sci 255). Here results on one of the realization of the laser ablation-glow discharge technique – combination of laser ablation and hollow cathode discharge are reported (Karatodorov S, Mihailov V, Grozeva M, Open Chem 13). Spatial separation of the laser ablation introduction from the hollow cathode discharge excitation is achieved. The sample analytical line emission intensity dependence on background gas pressure, sample cathode distance and discharge current is studied. This allowed optimization of the technique for increasing its analytical characteristics to be done.