Document mqVKxXzVYjbwrnQwGB7E1jmdJ

December 1, 1967 To: ^rom: .Robert A. Kehoe, M.D, J. Cholak Actually, I cannpt get excited about the differences since there is agreement that the concentrations (except for the flour) are in the fractional parts per million range,. In the case of the maize, we were able to use only two grams of material, since the container had opened in shipment and most of the material was lost. In the case of the other foods, five-gram samples were used. lie feel that we. can detect 0.5 microgram per sample and x*?ith a reproducibility of 0.25 microgram. We detected from 0.9' microgram to 2.3 micrograirs per sample, well within our satisfactory sensitivity and reproducibility. Since adequate quantities of all samples except the maize are still on hand, we are repeating the analyses using 10-gram samples.