Laser Ablation in Atomic Spectroscopy

Laser ablation (LA) is a unique technique to transform a solid sample into vapor-phase constituents, which then can be chemically analyzed by atomic spectroscopy. Ablation brings many exciting capabilities to the field of chemical analysis, primarily because of the laser-beam properties. The ability to analyze directly any solid samplewithout sample preparation and minimal sample-quantity requirements are just some of the unique capabilities. This article discusses current issues related to using LA in atomic spectroscopy. A general introduction to LA sampling is presented along with a comparison with other solid sampling techniques. The critical issues for all analytical techniques are calibration, accuracy, and sensitivity. Techniques that have been demonstrated to address these analytical characteristics and define these parameters for LA are investigated in detail. Finally, many unique applications are described, ranging from dating geological materials to providing crime-scene evidence. Most of these applications could not be performed without the use of a laser beam. The inductively coupled plasma (ICP) will be emphasized in this article because it is currently the most prevalent excitation and ionization source for chemical analysis using LA.