| Popis: |
Laser-induced breakdown spectroscopy (LIBS) is a novel method of elemental analysis based on a laser-generated plasma. Pulses from a laser are focused on a sample to atomize a small amount of material resulting in the formation of a microplasma. Because of the high plasma temperature, the resulting atoms are electronically excited to emit light. The plasma light is spectrally resolved and detected to determine the elemental composition of the sample based on the unique emission spectrum of each element. Because of the simplicity of the method, it is suited for analyses that cannot be carried out using conventional methods of atomic emission spectroscopy (AES). This is particularly true for measurements that must be conducted outside of an analytical laboratory. A particular advantage of LIBS is the ability to analyze most types of samples without any preparation. This allows the interrogation of samples in situ, providing rapid measurement capability, permitting the method to be used in the analysis of gases, liquids, and solids in a variety of different sampling configurations. Although LIBS provides sensitive detection for many elements, it is not an ultrasensitive detection technique. In addition, under field conditions, the method typically does not provide the high accuracy and precision offered by laboratory-based methods of AES. Although basically an element detection method, chemometric methods of analysis are being developed to analyze the LIBS spectrum to provide identification of chemical substances (e.g. explosives, pathogens, and chemical agents). |
