Protocol Development for Purification and Characterization of Sub-Fossil Insect Chitin for Stable Isotopic Analysis and Radiocarbon Dating
Issue Date
2001-01-01Keywords
characterizationchitin
Coleoptera
Endopterygota
Neoptera
Pterygota
Cumbria England
nitrogen
N 15 N 14
applicationsEnglandchemical analysisreconstructionArthropodaMandibulataInsectaisotope ratiosGreat BritainUnited Kingdomaccelerator mass spectroscopymass spectroscopyspectroscopybiochemistrypaleoclimatologyEuropeWestern EuropeCenozoicQuaternaryC 14carbonisotopesradioactive isotopesInvertebrataC 13 C 12stable isotopesabsolute age
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Hodgins, G. W. L., Thorpe, J. L., Coope, G. R., & Hedges, R. E. M. (2001). Protocol development for purification and characterization of sub-fossil insect chitin for stable isotopic analysis and radiocarbon dating. Radiocarbon, 43(2A), 199-208.Journal
RadiocarbonDescription
From the 17th International Radiocarbon Conference held in Jerusalem, Israel, June 18-23, 2000.Additional Links
http://radiocarbon.webhost.uits.arizona.edu/Abstract
Reliable radiocarbon dating depends upon well-defined samples. We have been investigating whether or not reliable 14C dates can be obtained directly from sub-fossil insect cuticle or biochemical fractions derived from it. Initial carbon and nitrogen stable isotope measurements on sub-fossil insect chitin from species with known feeding behaviors found within a single site (St Bees, Cumbria) clustered in a manner reminiscent of trophic level effects seen in terrestrial ecosystems. Although this finding implied some chemical stability, the measurement of CN ratios from the same samples indicated compositional variability. In addition, 14C dates obtained from these same samples were different from dates obtained from plant macrofossils found at the same depth. We have experimented with protocols designed to biochemically reduce chitin to its principle carbohydrate component glucosamine with the aim of using this compound to generate reliable 14C dates. Solvent extractions of sub-fossil chitin were carried out to remove both endogenous and exogenous lipid-soluble materials. Base hydrolysis reactions designed to extract polypeptides retained surprisingly high levels of contaminating amino acids. Proteinase K enzyme treatment had little affect on the level of amino acid contamination. Strong acid hydrolysis reactions designed to depolymerize chitin to glucosamine yielded only 5% glucosamine. Clearly alternative methods of chitin depolymerization must be identified before the purification and 14C dating of glucosamine from sub-fossil chitin becomes practical.Type
Proceedingstext
Language
enISSN
0033-8222Scopus Count
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