Open Access Dissertation
Date of Award
Dr. David M. Coleman
A new "zero-bias" spark source was used as an ablation device for the analysis of solids with ICP-AES. Direct solid analysis has an inherent advantage for ICP applications as it allows a dry plasma to be maintained. This helps minimize the background species present as many arise from the water and acids present in solution. The use of a spark source as a sample introduction method for ICP employs separate sampling and excitation processes. In separating these two events, both may be optimized individually to give enhanced performance. Dependence of spark parameters such as peak current and repetition rate on analytical characteristics of the ablation process was found on the spark stability and performance of ICP-AES. Lower currents and repetition rates are generally optimal. Analytical performance was evaluated by time profiles, a plot of emission intensity vs. time. Spark sampling and concurrent spectral emission are stable over time. Elements also tend to track each other was seen when ratioing minor elements signal intensity to the major constituent signal intensity of the sample. Linear correlations between measured signal intensities and concentrations of major and minor constituents in the samples were achieved. No internal standardization was required due to the similarity of the sample matrices for each series of samples. Experiments to measure spark reproducibility were performed. Acceptable accuracy and precision were achieved.
Shepherd, Billie A., "A zero-bias spark source for direct solid sample introduction for inductively coupled plasma atomic emission spectrometry" (1998). Wayne State University Dissertations. 1229.