Letter to L Love, Subject: Purchasing Approximately 100 GM of Separated CA40 at a Price Below the 0.25 Per Milligram Quoted in the Oak Ridge Catalogue (Encl: Estimate List, DTD 01/24/69)

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UNWERSITY OF CALIFORNIA, BERKELEY COLLEGE OF EXCINEERINC BERKELEY, CALIFORNU 61720 DEPARTMENT OF NUCLEAR ENCINEERISC During the past several weeks I have discussed with Stu Lich liter of LRL-Berkeley the possibility of purchasing approximately 100 gm of separated Ca40 (99.97%) at a price below the $0.25 per milligram quoted inthe Oak Ridge catalogue. He had indicated that a price of $0.13 per milligram was available but also indic a ted that since Oak Ridge has a rather la restock of Ca40 as waste from feed for production of CadB, it might be possible to get an even lower price. Our interest in the use of Ca40 is involved with a method for the direct measurement of the rate of calcium loss from bone. I n our technique,the Ca40 is fed orally and intravenously to patients in an effort to reduce significantly the abundance of other calcium isotopes(especially Ca48) in the rapidly miscible pools In this way i t is possible to reduce the abundance of Ca48 i n blood, and if the in take of dietary Ca is restricted t o Ca40, the only Ca48 source tothe blood is the loss of C a from bone. Hence the measurement of the rate of loss of Ca from bone may be effete d by determination of Ca48 pilot study, which required the use of approximately 6-7 g m of separated C aq we were able to reduce the Ca48 abundance i n blood t o about 70% of its normal value and through a 20 day study showed that the technique is feasible and leads to results of significantly higher accuracy than could be obtained from the available indirect

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The major advantages of such a method are 1) a if i cant improvement inthe accuracy of measurements, and 3)since stable isotopes are used, it may be possible t o perform such studies on children where the use of radioactive tracers is most undesirable. We have applied for and have obtained a grant from NIHto perform studies using this technique. protocol requires the use of up t o 15 gm o f Ca40 per study and is of course the major expense involved inthe work. minim1 amounts of Ca46948 would be quite a boon a s it would provide for significant flexibility in the ex peri - mental program, and would also provide for measurements on a large enough sampling to handle problems due t o differences amongst the population. the price of Ca40 containing We are immediately interested in obtaining approxim at ely 100 gm of high purity Ca40 and wish t o start our experimental program a s soon as possible (our grant will be available in several weeks and w e have $6000 of other funds immediately available).I would appre i ate receiving word on the availability and price of the Ca'O and the procedure required for the purchase of the Ca4O atthe earliest possible date. Thank you for your consideration of this matter.