Punched Card System for Radioisotopes H. R. LUKENS, Ja., E. E. ANDERSON, and L. J. BEAUFAIT, JR. Western Division, Tracerlab, lnc., Richmond
3, Calif.
A simplified punched card system for radioisotopes is presented. The system has been found to eliminate tedious searching of the tahles in order to identify an isotope on the basis of its radiation characteristics and half life.
A
P U K C H E D card system codifying some basic characteristics of radioisotopes has been in use in this laboratory for over a year. While other isotope card catalogs have been devised (1-3), it is felt that the one presented here is sufficiently different in purpose and arrangement to warrant description. The purpose of the isotope card catalog is to facilitate the identification of unknown radioactive isotopes on the basis of half life and radiation. Consideration was taken of minimum half lives encountered in this laboratory, the uncertain quality of counting data when dealing with unknown isot>opes,and the possibility that expansion of the system may be desired in the future. As a result of the above considerations a coding system \vas devised which selects a small group of isotopes, rather than one or two cards. This allows for the possibility that data reliability and sample history may be important factors. Also, it wa3 decided that unless an isotope had a half life of over 5 hours or was related to a greater than 5-hour-half-life isotope by genesis or isomerism, it would not be cataloged. Stable isotopes were a h to be eliminated from the system, since t'hey are not involved in its purpose. As a result of these deletions the numher of cards needed for the system was reduced from over 1000 to 375. I t is believed that this arrangement excludes only those isotopes not normally worked with or wed in either a commercial or a government laboratory. For a particular laboratory dealing in isotopes with half lives shorter than 5 hours, the addition of a f e x card3 would be a simple task. The case where one Fishes to find the characteristics of a certain isotope is correlative to the purpose of the catalog, hut is handled adequately by standard isotope tahles. For this reason, provision has not been made for the rapid selection of a specific iwtope. The card chosen for the system wag the AZcBee Key$ort Form IiS 581B, a 5 X 8 inch card with a single row of numbered holes spaced along its periphery. This card is of adequate size t o holcl a large amount of information and is easy to manipulate. Provision is made on the card for using groups of four holes (adjacent holes numbered 1, 2, 4, and 7 ) to code numbers from 1 to 14. Because of the generous size of the card there is room for additional information as may be needed. Only slightly more than one half of the available holes are now assigned, assuring the continued and expanding usefulness of the cards. I n addition to the description of a radioisot'ope given by the punched holes, use is made of the face of the card to give more exact half life and energy values. Modes of format,ion, per cent of total radiation of emksion, decay scheme?, and conversion coefficients are also given. Figure 1 shows a sample card of phosphorus-32, and illustrates the coding arrangement. The data used in preparing the cards iwre obtained from the Kational Bureau of Standards (4). The code chosen involvew simple characteristics which are assigned but one hole each. These simple properties are: ( a ) emits alpha particles, ( b ) emits negatrons (electrons emitted from the nucleus), ( c ) emits positrons, ( d ) emits gamma radiation, ( e ) emits electrons (internal conversion electrons), (f)decays by K capture, ( 9 ) decays by isomeric transition, ( h ) is a fission product, (i) has a radioactive daughter, (j) belongs to the thorium (-In)series, ( k ) belongs to the neptunium (4n+1) series,
651
( I ) belongs to the uranium ( 4 n f 2 ) series, ( m ) belongs to the actinium (4nf3) series, and (n)is naturally occurring. Possession of any of these characteristics is signified by punching the appropriate hole. Certain other properties which the authors have coded may be termed quantitative to distinguish them from the simple characteristics above: half life, maximum gamma energy, predominant gamma energy, maximum positron energy, maximum negatron energy, predominant negatron energy, and maximum alpha energy. The decision to include the predominant gamma and negatron energy stems from the fact that the amount of radiation of maximum energy is sometimes relatively small compared to radiations of lesser energies. Thus absorption or pulse analysis data will often yield predominant energies as better data than maximum energy. Each of the quantitative properties requires a group of four holes to describe the approximate half life and energieg of a given radioisotope. In addition, a group of eight hole- is uqetl to designate atomic number. As mentioned above, there are groups of four adjacent holes numbered 1, 2, 4,and 7 which may be used to codify any number from 1 through 14. By dividing the half lives and energies into classes and assigning a number to each class it waq possible to achieve a code with the desired selectivity. The half life classes with their assigned number are: Class KO. Less than 1 minute 1 1 minute up to 1 how -9 1 hour-1 day 3 (2 1) 1 day-3 days 4 3 days-10 days 5 (4 1) 10 days-30 days 8 30 days-1 year I 1 year-10 years 8 (7 1) 10 years-100 years 9 Greater than 100 years 11 [Sumbei 10 was not used because it requires three punches for cod-
+ + +
-
ing (7
+ 2 + I).]
The energy classification for gamma, positron, and negatron emission is as follows: Class, 1I.e.v. 0 up to 0.2 0 2-0 5 0 5-0 8 0.8-1 2 1 2-1 8 1 8-2 5 2 5-5 Greater than 5 m.e.v.
KO.
1
2
3 (2 4
5 (4 6 7 8 (7
+ 1)
+ 1) + 1)
The classification of alpha particle energies necessitated a code involving three punches and is given below:
so.
Class M.e.v. 0 up to 3.0 3 0-4 0 4 0-5 0 5 0-5 3 5 3-5 6
5 6-5 9 5 9-6 2 6 2-6 5 6 5-6 8 6 8-7 1 7 1-7 5 7 5-8 0 Greater than 8 0
1 2 3 (2 4 5 (4 6 7
+ 1) + 1)
8 9 10 (7 11 12 (7
13
+ 2 + 1) + 4 + 1)
ANALYTICAL CHEMISTRY
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to the characteristics sought. It is orily n a t u r a l t h a t increased sorting proficiency results from d E M I T 1-ER increased familiarity with the system. For example, pure s K gamma emitters may ebe found rapidly by IT first selecting those isotopes which decay by isomeric transition, then rejecting thoseTvhich emit elec4N + I SERIES trons (to eliminate RADIOACTIVE internal converqion cases); the lessexperiDAUGHTERS: enced 11ould possibly m e the more tedious method of selccting the gamma emittere, Figure 1. Drawing of Punched Card for Phosphorus-32 then rejecting the Illustrating coding arrangement and punches necessary to describe the isotope alpha emitters, positron emitter., etc. I t is felt that the codification of radioisotopes by punched cards These claqsifications plus the coding arrangement qhon.n on is a valuable addition to the scientific library. The modest Figure 1 may be placed on a blank Keysort card. This may be number of cards needed for the ?>-,tern resulted in a minimum of attached to the container holding the cards, where it will serve eypense in time and material., while the time required to identify as a ready indev to the system while sorting. a certain isotope from a given pet of properties has been greatly The atomic number designation is accomplished by using two reriuceJ in the authoi s' laboratory by this card ??.stem. adjacent groups of four holes. The group on the left de-cribes the class of ten, while the group on the right describes the unitq. LITER-IlURE CITED For evample, 4 + 2 ( 6 ) punched in the left-hand group and i + 1 ( 8 ) punched in the right-hand group designate atomic number 68 (1) Bonine, J. J., and Laing, II,,S i t c l e o i i z c s , 11, ( 2 ) , 65 (1953) ( E r ) . Finding an isotope card for revision purposes is aided by ( 2 ) Lenihan, J. 11.A , , Brit. J . ,4ppl. P h y s . , 3, 29 (1952). this feature, and 1s the only reason for the inclusion of this feature (3) Murphy, G. AI., J . Chein. Educ., 24, 556 (1947). (4) Katl. Bur. Standards, Ciic 499 and supplements in the system. The cards are manually sorted n-ith a McBce Keysorter needle RECEIVED for revleu .luguot 2 1 , 1953. lccepted J a n u a r y 2 2 , 195%. probe by the standard method of selection and rejection according
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Identification of Polyhydric Alcohols in Polymeric Esters J. F. SHAY', SUSAN SKILLING2,and R. W. STAFFORD American Cyanamid Co., Stamford, Conn.
By a modified saponification procedure, the poll-hydric alcohol fraction of a polyester resin can be separated. The component alcohols can be identified by infrared spectral analysis, using the spectra of commercial alcohols as comparative standards. The method provides an effective means of identification for individual polyhydric alcohols and for binary mixtures.
T
HE original polyester (alkyd) resins contained glycerol ex-
clusively as the polyhydric alcohol component and hence presented no analytical problem in this respect. The gradual replacement of glycerol, in whole or in part, by other polyhydric alcohols, however, soon necessitated a series of analytical investigations which culminated qualitatively in the procedure proposed by Orchin ( 8 ) ,which in the past has been applied successfully to polyhydric alcohol fractions isolated according to methods developed in this laboratory ( I S ) . The Orchin procedure, vhich 1
Present address, Fortier Plant, American Cyanamid Co , Avondale,
La 2
Present address, H a r r a r d Mediral School, Cambridge, Mass.
is based on the oxidative scission of vtc-diols with periodic acid, was applicable a s follows to the polyhydric alcohols commercially available at that time: Glycerol, if present, is converted to formic acid b y oxidation with a solution of periodic acid which has been carefully neutralized Kith standard alkali; the formation of formic acid is detected with methyl red indicator. Ethylene glycol is converted to formaldehyde, which can be detected by a color test involving alkaline phloroglucinol ( 1 2 ) . Propylene glycol yields acetaldehyde, which also gives a red coloration n ith alkaline phloroglucinol. hcetaldehyde may be distinguished from formaldehyde by the iodoform reaction. Diethylene glycol, which is not a vzc-diol, is not cleaved by periodic acid oxidation. I n the absence of the above polyalcohols, the presence of diethylene glycol can be substantiated by the preparation of the 3,5-dinitrobenxoate. Periodic acid oxidation has been applied by a number of eubsequent investigators, most of whom were concerned with quantitative estimations, Kewburger and Bruening ( 7 ) determined glycerol in the presence of ethylene and propylene glycols by titration of the formic acid liberated upon oxidation with potassium periodate. Pohle and Mehlenbacher ( I O ) analyzed mix-
