Dataset: Brault 2014: Compound-specific Carbon in sperm whale dentin
Deployment: lab_UCSC_Koch

Materials and methods for analysis are described in detail in the text. Briefly, a homogenized sample of sperm whale dentin was split into sub-samples. Three received "Conventional" extractraction (decalcification with 0.5N HCl, rinsing with water to neutrality, freeze-drying) and three were not treated ("Raw"). Samples were hydrolyzed with 6 N HCl for 20 h at 110°C, then trifluoroacetic anhydride (TFAA) derivatives were prepared. Samples were analyzed for amino acid carbon and nitrogen isotope composition on a Thermo Trace gas chromatograph coupled to a Thermo Finnigan DeltaPlus XP isotope ratio mass spectrometer. Ideally, samples were injected 3x, and reported isotopic values represent means and standard deviations (stdv) in ‰ relative to the V-PDB standard. For several lysine (Lys) samples, the δ13C value is based on a single injection, so stdv is not calculated. Details on columns used, injection, and furnace ramp parameters are presented in the paper. The amino acid δ13C values were determined from the measured values of the amino acid with corrections based on an amino acid mixture standard for which isotopic values had been independently determined by offline elemental analyzer analysis. Using this approach, the δ13C values of 13 amino acids could be reproducibly quantified: alanine (Ala), glycine (Gly), threonine (Thr), serine (Ser), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), hydroxyproline (Hpro), aspartic acid + asparagine (Asp), glutamic acid + glutamine (Glu), phenylalanine (Phe), and lysine (Lys). The amino acid molar percentages (Mol %) were determined from the peak areas using an external standard approach and based on the amino acid standard versus sample peak areas. For Mol %, data for Hpro and Pro are combined, and reported under Pro.