REPORT FOR ANALYTICAL CHEMISTS champ stated t h a t much of t h e d a t a to be included on the N R C proposed certificate is listed in t h e catalog of radioisotopes issued b y most producers. Decay schemes, half-lives, chemical a n d physical form of t h e radioisotope, method of assay, a n d limits of accuracy of the assay method are, for example, included in t h e O R N L catalog. H o u t e r m a n s remarked t h a t in merchandising other products there is usually a penalty for underweight or failure to give full measure; his suggestion t h a t a similar penalty be invoked for radioisotope shipments which are under strength drew a p preciative laughter. T h e International Atomic Energy Agency's Physics Section Laboratory does neither fundamental nor applied research, H a n s H o u t e r m a n s explained. T h e p r i m a r y function is t o supply standards for t h e developing countries. "While m a n y countries have specialized laboratories to prepare standards, it would be unwise for developing countries to do standardization," he said. Consequently t h e I A E A supplies this service for them. " T h e I A E A has shipped over 1200 samples to some 100 different installations this y e a r , " he said. The primary method of standardization is coincidence counting. F o r pure beta emitters, 4?r counting is used in conjunction with t h e efficiency tracing method. M a n y of t h e standards are for use in medical research so "mock-iodine" (Ba l ; l 3 -Cs 1 3 7 in proportions to simulate I 1 3 1 ) is a n imp o r t a n t standard. N e x t y e a r I 1 3 1 , Ce 14 *, Sr 90 , S3B, Fe 5 9 , a n d Cr 5 1 are to be added to t h e distribution. These standards, though intended primarily for developing countries, m a y be purchased b y a n y l a b o r a t o r y ; t h e cost is much lower t h a n comparable U. S. standards. H o u t e r m a n s explained t h a t the International B u r e a u of Weights and Measures in Paris is the primary responsible standardizing body in t h e world a n d t h a t the I A E A does n o t presume to operate a t the same level of authority as the Bureau. Unfortunately, the Paris group can distribute only about two standards a year, a n d these go only to a few laboratories. T h e I A E A , H o u t e r m a n s suggested, can a n d h a s acted upon occasion as a mediator
or referee in resolving disagreements among different laboratories. By submitting samples to a number of laboratories (as they plan to do in the case of Cs 1 3 7 ), a n d correlating and communicating results to t h e participants, t h e I A E A serves a most useful purpose. H o u t e r m a n s stated t h a t , as a result of both his attendance of the N R C meeting a n d his participation in t h e panel, he hoped t o m a k e t h e Vienna laboratory more versatile a n d more useful.
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Summary The entire panel presentation a n d discussion lasted almost twice the allotted time, a n d participation b y both audience a n d panelists w a s spirited. T h e general impressions left by t h e discussions a n d comments can perhaps be summarized as follows: 1. There is a need for better nuclear data. Where uncertainty exists, consistent use of selected values would be helpful. 2. Information and instruction are needed to aid the non-specialist in deciding when absolute standards are really needed and how to use them. 3. A better understanding of radiochemical techniques would lead to more intelligent use of radioactivity standards by some purchasers. 4. Standards producers should supply more information concerning the method of assay, errors, and chemical form of the standard. 5. Probably the quantity of standards now available is adequate; the quality may, however, leave something to be desired. The work of the N R C subcommittee should do much to alleviate problems arising from items 1 through 4 above. As a result of the concentrated effort of t h e individuals in t h e subcommittee a n d other scientists engaged in nuclear analysis a n d radiochemistry, t h e difficulty indicated in item 5 should be considerably improved. T h e two-day program of meetings, p a pers, a n d panel discussion has r e sulted in a better understanding of the problems of standards a n d standardization a n d should provide strong encouragement to all radiochemists to improve techniques. END m
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