Date of Award
Doctor of Philosophy (PhD)
R. Kenneth Marcus
Leah B. Casabianca
Carlos D. Garcia
Elemental analysis is a necessity in nearly every field of science due to the importance elemental composition plays in compound characterization, productivity, toxicity, etc. Numerous techniques exist to determine elemental composition, but when analyzing metal content specifically, atomic spectroscopy is typically used due to the low detection limits provided. The gold standard in atomic spectroscopy is inductively coupled plasma – optical emission spectroscopy/mass spectrometry (ICP-OES/MS), which provides excellent performance for both qualitative and quantitative studies. However, these instruments are expensive to acquire and operate which prevents their use in many academic laboratories. The ideal instrument for metals analysis would be a low-cost, low footprint instrument capable of similar performance to and higher throughput than an ICP. Towards this end, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) was developed. The LS-APGD is a small format glow discharge plasma that is capable of acting as both an excitation source for OES and an ionization source for MS. The cost barrier of the LS-APGD is incredibly low and operation costs are also far lower than ICP due to its compact size and low consumables requirements. The utility of the LS-APGD has been widely studied but has largely been constrained to analytes in neat solution instead of “real” samples in complex matrices. Presented in this dissertation are developments in optimization of the LS-APGD operating conditions for various applications of increased complexity.
Works include an imaging study of the LS-APGD plasma and the implications of those results on the parameterization methods typically utilized for LS-APGD analysis. Also described is a novel parameter optimization method and a detailed line selection study for OES analysis. The use of capillary-channeled polymer (C-CP) fibers as a stationary phase for online metal pre-concentration prior to LS-APGD-OES analysis is also presented. Finally, the culmination of all previous works is presented through the application of on-line organics removal prior to trace metal quantification in cell culture media via LS-APGD-MS. The research presented in this dissertation has improved upon neat solution analysis such that complex, real-world samples can now be analyzed.
Hall, Katja, "Optimization of the Liquid Sampling-Atmospheric Pressure Glow Discharge for Varied Spectrochemical Applications" (2021). All Dissertations. 2789.