Laser Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique that can be used for the detection and characterization of materials. In LIBS, a focused laser beam is used to generate a plasma plume on the surface of solid and liquid samples or inside the sample volume of gases, liquids, and aerosols. Each excited atom in the plasma emits a unique set of spectral lines, particularly in the optical region of the spectrum. Therefore, this optical emission can be collected and analyzed to determine the chemical composition of a sample. A LIBS plasma can be generated as a single event using just one laser pulse or using repetitive laser pulses. As a result, localized microanalysis with lateral and depth profiling information is easily obtained. Remote sensing of materials is also possible with LIBS, since only photons need to come in direct contact with the sample. The ability to perform analyses on samples at a standoff distance is especially important when dealing with hazardous materials, samples located in a dangerous environment, or in physically inaccessible locations. LIBS has a distinct advantage over many other techniques since little or no sample preparation is needed before analysis, and it can be used for rapid real-time analysis in field operations. Quantitative analytical results can be obtained from LIBS by using conventional (oneelement) or multivariate calibration. Recently, calibration-free LIBS analysis has been demonstrated as the semiquantitative determination of elements, based on theoretical plasma models. With LIBS, there are no specific requirements for the sample to fluoresce, be Raman-active or infrared-sensitive. It is truly a universal technique, where any sample type can yield a LIBS spectrum.