Improved Method for Isolation and Purification of Underivatized Amino Acids for Radiocarbon Analysis.
Naoto F IshikawaYu ItahashiThomas M BlattmannYoshinori TakanoNanako O OgawaMasako YamaneYusuke YokoyamaToshi NagataMinoru YonedaNegar HaghipourTimothy I EglintonNaohiko OhkouchiPublished in: Analytical chemistry (2018)
We have improved a method for isolation and purification of individual amino acids for compound-specific radiocarbon analysis (CSRA). To remove high-performance liquid chromatography (HPLC) eluent blanks from isolated amino acid fractions prior to the radiocarbon (Δ14C) measurement, each fraction was filtered through a membrane filter and then washed with diethyl ether twice. Radiocarbon measurements on standard amino acids processed and purified with the above method using elemental analyzer-accelerator mass spectrometry resulted in Δ14C values that were in strong agreement ( R2 = 0.998) with the original Δ14C value of each amino acid standard. From these measurements, we calculate dead and modern carbon contamination contributions as 1.2 ± 0.2 and 0.3 ± 0.1 μgC, respectively, which are consistent with direct assessments of HPLC procedural blanks of 1.0 ± 0.8 μgC per sample. These contamination constraints allow correction of measured Δ14C values for accurate and precise CSRA and are widely applicable to future archeological and biogeochemical studies.
Keyphrases
- amino acid
- high performance liquid chromatography
- mass spectrometry
- simultaneous determination
- tandem mass spectrometry
- solid phase extraction
- gas chromatography
- ms ms
- liquid chromatography
- risk assessment
- high resolution
- drinking water
- magnetic resonance imaging
- computed tomography
- health risk
- capillary electrophoresis
- human health
- climate change
- ionic liquid