A novel tertiary prep-HPLC method for the isolation of single amino acids for AMS-radiocarbon measurement

作者：Fernandes Ricardo^*; Koudelka Tomas; Tholey Andreas; Dreves Alexander

来源：Journal of Chromatography B-Analytical Technologies in the Biomedical and Life Sciences, 2017, 1058: 85-92.

DOI：10.1016/j.jchromb.2017.05.017

• Radiocarbon
• Accelerator mass spectrometry
• Amino acids
• Bone collagen
• HPLC

AMS-radiocarbon measurements of amino acids can potentially provide more reliable radiocarbon dates than bulk collagen analysis. Nonetheless, the applicability of such an approach is often limited by the low-throughput of existing isolation methods and difficulties in determining the contamination introduced during the separation process.
A novel tertiary prep-HPLC amino acid isolation method was developed that relies on the combustion of eluted material without requiring any additional chemical steps. Amino acid separation was carried out using a gradient mix of pure water and phosphoric acid with an acetonitrile step in-between runs to remove hydrophobic molecules from the separation column. The amount of contaminant carbon and its C-14 content were determined from two-point measurements of collagen samples of known C-14 content.
The amount of foreign carbon due to the isolation process was estimated at 4 +/- 1 mu g and its C-14 content was 0.43 +/- 0.01 (FC)-C-14. Radiocarbon values corrected for carbon contamination have only a minor increase in uncertainties. For Holocene samples, this corresponds to an added uncertainty typically smaller than 10 C-14 years.
The developed method can be added to routine AMS measurements without implying significant operational changes and offers a level of measurement uncertainty that is suitable for many archaeological, ecological, environmental, and biological applications.

• 出版日期2017-7-15