30) to have advantages over derivatization in organic solvents: little or no racemization
occurred and excess reagent was destroyed, eliminating GC-MS interference.
The majority of these assays use N-trifluoroacetyl-L-prolyl chloride (14, 20, 21) or the corresponding N-heptafluorobutyryl derivative (15, 22), reagents that have been noted in the literature for their lack of stereochemical purity, their instability, and unpredictable racemization
(23-27); therefore, some considerable care is required for the effective use of these reagents.
These authors describe a sequence of lacustrine, lake-shore and dune deposits at the Williams Point site, Lake Eyre, that have been cross-dated by 14C (both conventional and AMS), TL, 230Th/234U and amino-acid racemization
Microbially-induced promotion of amino acid racemization
in bone: isolation of the microorganisms and the detection of their enzymes, Journal of Archaeological Science 20: 159-68.
Various 'absolute' dating techniques, namely thermoluminescence (TL) of sediments and flints, electron spin resonance (ESR) of horse teeth and radiocarbon and also relative dating techniques such as amino-acid racemization
rate determinations have been applied to material from Hoxne.
The similarity to Swanscombe, supported by results from amino-acid racemization
, suggests a correlation with Oxygen Isotope Stage 11 (c.
Pleistocene chronologies should be constructed using the widest range of appropriate dating techniques -- such as radiocarbon, luminescence, electronspin resonance, uranium series and amino-acid racemization
An amino acid racemization
chronology of Tabun, in Ronen (1982): 43-54.
Amino acid racemization
(AAR) dating has been attempted on rock paintings in South Africa (Pager 1972: 356-9) and in the United States of America (McCarthy et al.
usually comes about as a result of faulty manufacturing procedures, such as at the point that laetrile was extracted from its source in apricot kernels in a substandard factory.
In the samples prepared with a tin(II) 2-ethylhexanoate as the catalyst, racemization
can occur during polymerization, which strongly influences stereoregularity of poly(L-lactide), even with the isosorbide in the main chains.
alpha]-Methylacyl coenzyme A racemase (AMACR) is an enzyme that catalyzes the racemization
of [alpha]-methyl-branched carboxylic coenzyme A thioesters.