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Re: Lerner on orion Castor oil impact on C14 tests
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With regard to ms. Lerner´s post:
Greg Doudna pointed out some time ago that if one tests a sample more than
once and arrives at radically different results, the laboratory
automatically regards this as proof of contamination. Hence, if retesting
by the same method of samples suspected of being outliers arrives at
remarkably different dates from previous results, there will be a prima
facie case for contamination.
Prof. Karl Anker Jørgensen, of the biochemistry department in the Univ. of
Århus (Denmark), tells me that the immersion times in the baths ordinarily
used to clean samples for C-14 would be insufficient to remove castor oil
contamination, which is why we have asked the curator of the National
Museum to experiment with such procedures.
Next, we are asking Dr. Rasmussen to make control tests by contaminating
parchment samples of known date with both modern and ancient oils: this
will provide controls on the nature and extent of various types of
contamination.
best regards,
Fred Cryer