Document Type
Thesis - University Access Only
Award Date
2006
Degree Name
Doctor of Philosophy (PhD)
Department / School
Chemistry
Abstract
The chemical analysis of ice cores from polar regions can provide information on past climate and atmospheric conditions. The chemical analysis of these ice cores is traditionally performed on discrete samples cut using a bandsaw. The preparation of discrete samples is time consuming (~1 meter per day) and involves steps where contamination can occur. Ion chromatography is commonly used for the chemical analysis of the discrete samples. Significant increases in speed without sacrificing detection limits and temporal resolution have been recently made through the inclusion of a melter, which allows for simultaneous melting and decontamination of core, into an analysis system. This allows for the melting and analysis of several meters of ice per day while reducing sample handling. Currently, the meltwater stream produced is analyzed using spectroscopic methods. However, not all chemical impurities in ice cores can be directly or indirectly determined in this manner. Therefore alternate methods need to be explored. A new method of ice core chemical analysis was developed where a melter provides meltwater to the injection loops of several ion chromatographs. Multiple ion chromatographs, run in series, allows for the continuous analysis of all major ionic impurities within ice cores (Na+ , NH/, K+ , Mg2 +, Ca2+, er, N03-, so/-). This method successfully combines the speed of the continuous melting and decontamination with the versatility and low detection limits of ion chromatography. The increased analysis speed was accomplished without sacrificing temporal resolution. While this technique provides high resolution analysis for these ionic chemical impurities, it does not allow for the detection of other chemical impurities (e.g. H202 and CH20) which have traditionally been detected using a melter in combination with spectroscopic analysis. Chemical impurities, such as H202, are known to be electrochemically active and would lend themselves toward this type of detection system. However, electrochemical detection has not been utilized for the analysis of chemical impurities in ice cores. In order to show that electrochemical detection is a viable technique for the analysis of ice cores, an electrochemical detector for H202 was explored. Ferrocyanide and ascorbic acid, both with known electrochemical properties, were chosen as model compounds to show that electrochemical detection can be appropriate at ultra-trace levels. This information was then used to develop a detection methodology for a chemical impurity (H202) present in ice cores. The performance of several electrochemical cells was evaluated showing that electrochemical detection is indeed a viable technique for use in ice core chemical analysis. This work provides a first step in the integration of electrochemical detection into the continuous flow analysis of ice cores.
Library of Congress Subject Headings
Ice cores -- Analysis
Chromatographic analysis
Format
application/pdf
Number of Pages
127
Publisher
South Dakota State University
Recommended Citation
Budner, Drew, "Development of a Continuous Analysis System for Ice Cores Using a Melter with Ion Chromatography and an Initial Study of an Electroanalytical Technique for Ice Cores" (2006). Electronic Theses and Dissertations. 1236.
https://openprairie.sdstate.edu/etd2/1236