ATTACHMENT 7 Following Dr. Oppenheimer's directive of 16 August 1944, we have launched upon the two programs mentioned therein: a. The development of methods of detection of plutonium in the excreta. b. The development of methods of detection of plutonium in the lung. At present we have four people working on item (a): Miss Anne Perley, Mr. Bob Pryxell, Mr. Don Mastick and Pvt. Wheeler. We have applied for two S.E.D. men with some laboratory training to assist in this group. Miss Perley is concerned with a method devised by the Chicago Health Group which involves the use of IR-1 resin. In view of certain difficulties involved in the use of the resin adsorption techniques, we feel it is necessary to develop a direct chemical method of isolation of the plutonium from urine, either as a check on the efficiency of the column or to entirely supplant the use of the resin. However, this method as presented would be less time consuming and more simple than direct chemical methods. Therefore, Miss Perley will continue her studies to perfect this method. Mr. Pryxall will be immediately concerned with the extraction of plutonium from urine fractions with cupferron. One of the complicating factors in the isolation of tracer quantities of plutonium from urine is the presence of calcium, magnesium, and iron. Their approximate concentration in urine is respectively, 4 10-3, 710-3, and 710-5 molal. In a 24 hour specimen these constitute an appreciable interference as even a small amount following through the separation process may make a highly absorbing plate for alpha-particles. Since we expect to be working with 1 to 50 counts per minute it is apparent this must be avoided. Mr. Pryxall feels this may be accomplished by some type of cupferron extraction, either from alkaline or acidic solutions. Mr. Mastick is working with the ether extraction of oxidized plutonium from the inorganic fraction of the urine. Various methods are either under trial or being discussed for the most effective method of separating the inorganic constituents from the urine. Other methods under trial are designed to carry the plutonium away from the urine leaving both the organic and inorganic fractions in the acidified solution. It is hoped that more than one chemical method may be developed in order to afford cross-checks on the methods. 1 23 August 1944 Pvt. Wheeler is at present acting as a general laboratory assistant. Item (b) has been discussed with Dr. Segre and Dr. Rovis and at the present is being taken up with Dr. Bacher. We would appreciate any suggestions relating to these matters. cc/Dr. Art Kahl File 2