Laser-induced plasma spectroscopy in the analysis of phosphate mining samples and archaeological materials

Laser-induced plasma spectroscopy (LIPS) is a versatile technique used in many academic and industrial settings. The LIPS technique is a well-established method for the rapid elemental analysis of various materials with little or no sample preparation. A laser pulse of sufficiently high power is tightly focused onto a sample surface. A hot, intense plasma is formed as the surface is heated by the laser and as material is ablated. The emitted radiation is spectrally resolved and the emitting species in the laser-induced plasma are identified. The elemental composition of the sample is then determined by its unique spectral wavelengths and line intensities.; Identification of materials is achieved by using these spectral “fingerprints” that are unique to each sample. The focus of this research is to use these fingerprints in a variety of applications. Spectral data were analyzed by linear correlation, nonparametric rank correlation, and principal component analysis. The feasibility of using these chemometric techniques in LIPS was compared.; Several studies involved the development and evaluation of various instrumental configurations, with the goal of optimizing a configuration for use in the phosphate industry. This research will discuss the development of field instruments that help to minimize contamination of matrix material (phosphate ore) by overburden or bedrock material through rapid field identification. Research has demonstrated the feasibility of accurately identifying material in its untreated, natural state with no sample preparation. The application of LIPS involves acquiring spectra of several selected samples, developing a library from these spectra, and using a correlation technique to match unknown spectra with well-characterized library spectra. Software was developed to rapidly carry out the correlation procedure and display material identification.; Furthermore, LIPS was used to study the archaeological significance of certain ceramics from the first century BC. Finally, the analytical matrix effects commonly found in LIP spectra were investigated.