[delta][sup.13]C (i) =
isotopic enrichment of tissue, at the beginning (dimensionless);
The
isotopic enrichment factor of denitrification can vary according to the denitrification rate constant and the substrate concentration (Ostrom et al.
That is, higher rates of denitrification result in higher (less negative) values of
isotopic enrichment and lower rates result in lower (more negative) values of
isotopic enrichment.
To overcome these difficulties in the GC/MS assessment of stable-isotope-labeled long-chain fatty acids in biological specimens, we have developed a new analytical protocol that includes the use of trimethylsilyl (TMS) esters as derivatized compounds and the calculation of
isotopic enrichment from calibration curves obtained from mixtures containing known
isotopic enrichments.
If we assume that [[delta].sub.species] = [[delta].sub.food ] + [delta] [plus or minus] [[sigma].sub.[delta]], where [[sigma].sub.[delta]] is the standard deviation of the values of
isotopic enrichment ([delta]) in various species given in Gearing et al.
Estimates of
isotopic enrichment of biota were made during the period of maximum enrichment and are reach (0-5 kin) averages.
