Date of Award

1-1-2012

Document Type

Campus Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

Stanley M Angel

Abstract

This dissertation describes fundamental and applied studies that have advanced the scientific community's understanding and application of Laser Induced Breakdown Spectroscopy (LIBS) during recent years. Chapter one is a broad overview of LIBS as a technique including a brief history, the theory behind the technique, and the instrumentation typically used. This chapter also introduces the concept of using two laser pulses in LIBS, termed Dual Pulse LIBS (DP-LIBS) and the enhancements typically observed. Chapter two describes an investigation into the mechanisms at work behind the enhancements seen in DP-LIBS. Specifically, the sample heating that occurs during DP-LIBS is quantified and correlated to the enhancement in emission and ablation that is observed. Chapter three changes gears and describes work that has been done with LIBS in bulk aqueous solution. This work is particularly aimed toward the application of monitoring key elemental species dissolved in ocean water at hydrothermal vent sites. This chapter reports the capability of LIBS to detect these elements of importance at concentrations that are relevant to hydrothermal vent chemistry. It also shows the advantages of using an internal reference for normalization of the variation typically seen in LIBS measurements. Another issue for LIBS and other analytical techniques is the presence of matrix effects. This chapter shows how the presence of different combinations of ions in solution affects the LIBS

emission intensity. This is a significant problem for LIBS in solids and in air, but the results delineated in this chapter suggest that the matrix effects for LIBS in bulk solution are minimal. This chapter also discusses the effects of elevated pressure on LIBS in bulk solution and lays the groundwork for future investigations. These results show great promise for applications where LIBS can be used to quantitatively determine species in bulk solution.

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