Date Approved

2008

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Abstract

Because the traditional acid-alkali-acid method for pretreating archaeological artifacts prior to radiocarbon dating is destructive to most materials, the possibility of developing an alternative pretreatment is important to preserving culturally- and historically-significant artifacts. The alkali step usually involves a 1M or higher concentration NaOH wash to remove humic acid contamination. The purpose of this work is to replace the alkali step with an equally effective, yet less harsh treatment. Charcoal soaked in a humic acid standard was used to mimic a contaminated artifact. Residues from treatments with NaOH, phosphate buffer (pH 8), and deionized water were characterized using THM-GC-MS. Preliminary results show that both NaOH and phosphate buffer are at least equally effective. The phosphate treatment was also used on two archaeological artifacts that were prepared nondestructively by using the plasma chemical oxidation (PCO) pretreatment. The resulting radiocarbon dates from these were statistically indistinguishable from dates produced by the traditional treatment process coupled with standard destructive combustion. iv

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Chemistry Commons

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