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The radioactive determination of uranium in sea water Wong, Robert 1950-03-21

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THE RADIOACTIVE DETERMINATION OF URANIUM IN SEA WATER. In Partial Fulfillment For The Master*s Degree In Chemical Oceanography by Robert Wong, B.A. UNIVERSITY OF BRITISH COLUMBIA (October, 19.50.) 2 THE UNIVERSITY OF BRITISH COLUMBIA V A N C O U V E R , C A N A D A T R Y October 2 , 1 9 5 0 . To Whom I t May Concern: T h i s i s t o c e r t i f y t h a t the t h e s i s e n t i t l e d "The R a d i o a c t i v e Determination of Uranium i n Sea Water" by Mr. Robert Wong measures up t o the r e q u i r e d standards of the Master's t h e s i s i n t h i s Department. Yours t r u l y , -ew THE RADIOACTIVE DETERMINATION -OF URANIUM IN SEA -WATER7""" ABSTRACT. The d e t e r m i n a t i o n o f s m a l l amounts o f uranium o f the o r d e r o f p a r t s per hundred m i l l i o n has u s u a l l y been c a r r i e d out by i n d i r e c t r a d i o a c t i v e measurements. Such measurements cannot be employed except when the r a d i o - elements are known t o be i n e q u i l i b r i u m . The s e p a r a t i o n o f the uranium and i t s isotopes; i n such s m a l l amounts:, i s accomplished w i t h the use o f an ion-exchanger and separated I i n a r a d i o a c t i v e l y pure s t a t e w i t h the use o f c o - p r e c i p i t a t o r s . the i r o n (and aluminum) b e i n g added. The a l p h a - p a r t i c l e a c t i v i t y o f the uranium i s determined as a measure o f i t s c o n c e n t r a t i o n . The method i s t e s t e d by two c o n t r o l t e s t s . A, v a r i a n c e o f 3.0$ f o r these t e s t s s u b s t a n t i a t e s the v a l i d  i t y o f the method but the e f f i c i e n c y o f the e x t r a c t i o n was approximately 50$. 1. INTRODUCTION It i s presumed that the ocean came into being as soon as the Earth cooled below the condensation point of water, and since that time i t has been receiving substances leached and eroded from the continents. Some of these substances have made the journey from the continent to the ocean and back again several times and may continue to do so. How ever, i n the case of the radioactive substances which cease to exist after a time, a limit to this phenomena exists. The non-radioactive sediments may come and go, but a l l the radio active elements, whether of long or short l i f e , cannot exist eternally but aire transitory. It i s then also true that uranium cannot exist forever. The determination of minute traces of uranium which are present in nearly a l l materials has received scant atten tion especially when one considers the quantity of data avail able concerning the radium content of a l l types of matter. In a few radioactive problems the uranium i s present in sufficient amount for determination by standard chemical procedure. In the majority of radioactive problems, p a r t i  cularly those of interest to tho geophysicist, such as the determination of geologic time and the production of radio active heat, equilibrium in uranium-238, uranium - 2 3 5 , and thorium series has been established. Equilibrium in the uranium-238 series i s established in less than 10 years; 3 g e o l o g i c a l l y a very short period of time. The other two series a t t a i n equilibrium i n much less than 1©^ years. I f the uranium-238 series i s i n equilibrium, the measurement of radon i s equivalent to a determination of the uranium or of any member of i t s s e r i e s . An extremely small amount of the gas&ous radon, the d i s i n t e g r a t i o n product of radium, can be e a s i l y separated from the other members of the series and measured by i t s i o n i z i n g e f f e c t . PREVIOUS WORK Hitherto no standard a n a l y t i c a l method f o r measuring uranium with the necessary degree of s e n s i b i l i t y has been known, electrometric methods f a i l i n g i n the case of extremely minute amounts of uranium owing to i t s very weak a c t i v i t y . A determination suggested by Joly (1), using a colorimetric method proposed by Walker (2), was undertaken 40 years ago. The quantity of uranium expected from the radium content amounted to over one milligram i n the 8 grams of sample but the actual weight of uranium ac t u a l l y present was .6 milligrams. However, he asserts that about one h a l f of the uranium present might have been l o s t i n the chemical opera t i o n . In 1930 Herculano de Carvalho (3) measured the amount of uranium i n the water from some springs i n Portugal using the colorimetric method with ferrous cyanide and found quan- —6 t i t i e s of about 10~ grams per l i t r e . Where large samples of water are available and the s o l i d content i s low, the uranium can be c o n s i d e r a b l y c o n c e n t r a t e d by e v a p o r a t i o n i n t o a s m a l l f r a c t i o n of i t s o r i g i n a l volume before the o t h e r substances d i s s o l v e d i n the water begin to c r y s t a l l i z e . I n sea-water, however, which h o l d s between 30 and 40 grams o f d i s s o l v e d s a l t s per l i t r e , the problem of f i n d i n g the minute amount o f uranium i s t h e r e f o r e much more d i f f i c u l t . Hernegger ( 4 ) , has developed an o p t i c a l method o f dete r m i n i n g uranium by comparing the f l u o r e s c e n c e i n u l t r a  v i o l e t l i g h t o f f u s e d sodium f l u o r i d e beads, t o which known and unknown amounts o f uranium have been added. He used a g l a s s spectrograph o f v e r y h i g h l i g h t - g a t h e r i n g power and by photographing the c h a r a c t e r i s t i c band-spectra due t o uranium f l u o r e s c e n c e and comparing the i n t e n s i t i e s w i t h those found w i t h the c o n t r o l s o f known uranium c o n t e n t . The method i s claimed t o e a s i l y d e t e c t uranium i n as s m a l l amounts as 10 ^ grams. I n c o l l a b o r a t i o n w i t h K a r l i k ( 5 ) , measurements o f the uranium content o f ocean water o f Norway wherein the uranium was concentrated from samples o f one -6 l i t e r or more, gave c o n s i s t e n t r e s u l t s a veraging 1.5x10 gram uranium per l i t e r . PRESENT WORK The sea water samples as o b t a i n e d were f i l t e r e d through glass-wool f i l t e r s t o e l i m i n a t e any s o l i d matter which would a d v e r s e l y i n f l u e n c e the e f f i c i e n c y of the ex change r e s i n . The seawater sample as obtained was s l i g h t l y a l k a l i n e and hence t o prevent c o l l o i d a l hydroxides from p a s s i n g through the exchange column unchanged,the pH was 5 a d j u s t e d t o 4 by the a d d i t i o n o f p u r i f i e d H C l . Each seawater o r c o n t r o l sample was then pumped through t h e i o n exchange column c o n t a i n i n g IR -120 i n the sodium form and U-238, U234, U235 and o t h e r d i v a l e n t o r h i g h e r valence i o n s were conc e n t r a t e d on the r e s i n . The uranium was then e l u t e d along w i t h o t h e r i o n s such as Fe and Ag^etc, which form complex i o n s w i t h NaCN. The complex was then decomposed by e v a p o r a t i n g w i t h concentrated ^SO^. P u r i f i e d F e C l ^ and A l C l ^ was then added to the s o l u t i o n and the b o i l i n g s o l u t i o n was p r e c i p i t a t e d w i t h c o n c e n t r a t e d NH^OH. By t h i s p r e c i p i t a t i o n , the uranium was a l s o p r e  c i p i t a t e d i f i n macro-amounts or c o - p r e c i p i t a t e d i f i n micro-amounts. T h i s p r e c i p i t a t e was t h e n t r e a t e d w i t h a d a p t a t i o n s from the procedure g i v e n by U r r y (6) f o r the d e t e r m i n a t i o n of s m a l l amounts o f uranium. In t h i s procedure, U-238 and i t s i s o t o p e s U-235 and U-234 are separated from a l l the o t h e r radio-elements by the use of c o - p r e c i p i t a t o r s . The sequence of c o - p r e c i p i t a t i o n i s such t h a t a l l the reagents need o n l y be f r e e of uranium, thorium, ionium, and a c t i n i u m . The i r o n and aluminum i n the s o l u t i o n are used as the c a r r i e r agents i n the f i n a l p r e  c i p i t a t i o n of the uranium. The c o n c e n t r a t i o n by these c a r r i e r s i s the important p r i n c i p l e of the method because the r a d i o a c t i v e measurement of the uranium r e q u i r e s a " t h i n l a y e r " of l e s s than a c e r t a i n t h i c k n e s s and consequently of l e s s than a g i v e n mass f o r a g i v e n a r e a . F o r very low uranium c o n c e n t r a t i o n s i t i s p o s s i b l e to separate the i r o n p l u s aluminum from the uranium and t o r e t u r n o n l y a s m a l l p o r t i o n o f the former as c o - p r e c i p i t a t i o n s , which r e s u l t s i n a much h i g h e r c o n c e n t r a t i o n f a c t o r . The f i n a l p r e c i p i t a t e of the oxi d e s o f i r o n , aluminum and uranium i s d r i e d , i g n i t e d , and weighed. The p r e c i p i t a t e i s ground and s p r i n k l e d on an adhesive s u r f a c e t o form a a t h i n l a y e r and the r a t e o f e m i s s i o n o f the a l p h - p a r t i c l e s from the uranium i s determined p h o t o g r a p h i c a l l y . The r a t e o f e m i s s i o n i s a d i r e c t measure of the number of atoms o f uranium present i n t h e t h i n l a y e r . PRINCIPLE OF ION-EXCHANGE Our use o f an i o n exchange r e s i n i n the i n i t i a l s e p a r a t i o n o f uranium from sea water warrants a b r i e f but necessary d i s c u s s i o n due to the d i f f i c u l t i e s a r i s i n g from the nature o f our exhaust s o l u t i o n , sea water. To i l l u s t r a t e the r e a c t i o n s o f i o n exchange r e s i n s , i t i s necessary o n l y t o s u b s t i t u t e a l a r g e , i n s o l u ^ b l e , s y n t h e t i c molecule i n p l a c e o f one of the i o n s i n equations t h a t i l l u s t r a t e o r d i n a r y double decomposition. The r e s u l t d e p i c t s a type o f r e a c t i o n t h a t w i l l t r a d e i o n s . The i o n exchange r e s i n s are a c t u a l l y l a r g e , i n s o l u b l e a c i d s and bases. I f the r e s i n i s a c a t i o n exchanger, i t w i l l possess r e a c t i v e a c i d groups as p a r t o f the r e s i n molecule. In any case o t h e r c a t i o n s can r e p l a c e the hydrogen of these a c i d groups t o produce i n s o l u b l e " r e s i n s a l t s " . As a s o l u t i o n con t a i n i n g c a t i o n s i s passed through a column c o n t a i n i n g l a r g e 7 numbers o f c a t i o n exchange r e s i n p a r t i c l e s , hydrogen i o n s are r e l e a s e d from the r e s i n ' s a c i d groups, and m e t a l l i c i o n s are absorbed. As a r e s u l t , the c a t i o n r e s i n bed becomes en r i c h e d w i t h m e t a l l i c i o n s . I f i t i s not necessary t o separate the sodium ions from a s o l u t i o n s as i n our case, the c a t i o n exchanger i s used i n the sodium form, t h a t i s , the r e s i n i s f i r s t t r e a t e d w i t h a s o l u t i o n of sodium c h l o r i d e to r e p l a c e a l l o f the hydrogen i o n s on the r e s i n with sodium i o n s . Then, when the s o l u t i o n s passes over the a c t i v e exchange c e n t e r s , sodium r e p l a c e s the o t h e r m e t a l l i c i o n s i n s o l u t i o n . There f o r e , i o n exchange r e s i n s form compounds w i t h d e f i n i t e com p o s i t i o n s which e n t e r i n t o chemical r e a c t i o n s as do o t h e r compounds. The r e a c t i o n s are double replacement o r metathesis r e a c t i o n s and, a t e q u i l i b r i u m , are governed by the law of mass a c t i o n . The c h i e f d i f f e r e n c e s between r e a c t i o n s of these compounds w i t h i o n s i n s o l u t i o n and the r e a c t i o n s between i o n s which are a l l homogeneously d i s p e r s e d i n s o l u  t i o n s , i s the r a t e at which equilibrium i s approached. In g e n e r a l , the mass a c t i o n law which holds f o r g r a n u l a r exchangers where a l l of the exchange takes p l a c e i n the i n t e r i o r of the p a r t i c l e s having a porous g e l s t r u c t u r e , takes the form o f the K err (7) equation: A ' - r BX = AX + B* m_ a _ _ m BX ( B + ) 8 An e q u a t i o n of t h i s type expresses the well-known f a c t t h a t t h e d i s t r i b u t i o n o f two i o n s of unequal charge depends upon the d i l u t i o n ; the more d i l u t e the ^ s o l u t i o n , the g r e a t e r the p r o p o r t i o n of the h i g h e r valence i o n i n the exchanger. In i o n exchange as i n other c h e m i c a l e q u i l i b r i a , the r e a c t i o n s are r e v e r s i b l e ; t h a t i s , i n the forward d i r e c t i o n we have the exhaustion and the r e v e r s e d d i r e c t i o n we have r e g e n e r a t i o n . In our p a r t i c u l a r case w i t h IR-120 i t i s recommended t h a t a 10% s o l u t i o n o f NaCl be the r e - generant i n the sodium c y c l e ; i n o t h e r words, the regenerant w i l l d i s p l a c e a l l c a t i o n s other than sodium from the r e s i n and thereby re juvenate ...the r e s i n . With sea water, we are c o n f r o n t e d w i t h the d i f f i c u l t y t h a t we have a p p r e c i a b l e amounts o f regenerant sodium ions i n our exhaust s o l u t i o n . Hence i t can be seen from our e q u i l i b r i u m e quation t h a t the exchanged form, AX, i s lowered by the i n c r e a s e i n B. Or i t may be s a i d t h a t our r e s i n exchange c a p a c i t y i s now lower. I t was t h e r e f o r e e s s e n t i a l t o conduct experiments t o determine e x a c t l y how t h e c a p a c i t y o f t h e r e s i n v a r i e s w i t h the c o n c e n t r a t i o n o f sodium i o n s i n the exhaust s o l u t i o n because our d e t e r m i n a t i o n of uranium i s q u a n t i t a t i v e . Furthe more, c a p a c i t y v a r i a t i o n s under such conditions|has not been recorded i n the l i t e r a t u r e . PRINCIPLE OF CO-PRECIPITATION There i s a fundmental d i f f e r e n c e between the chemistry of extremely small amounts of the radio-elements and that of the weighable quant i t i e s i n chemical a n a l y s i s . Thus, the condi t ion for c o - p r e c i p i t a t i o n i s not so much one of isomorphism as the formation of a p r e c i p i t a t e cons i s t ing of a compound whose anion forms an inso luble compound with the radio-element. Fa jan ' s rule as stated by Hevesy and Paneth (8) i s as fo l lows : "A ca t ion w i l l be absorbed by a d i f f i c u l t soluble s a l t when i t forms with the anion of the absorbing s a l t a compound, the s o l u b i l i t y of which i n the solvent i s s m a l l . " The le s s the s o l u b i l i t y of the compound involved and that of the absorbent, the stronger w i l l be the absorpt ion. In the fo l lowing t a b l e , (Table 1) most of the radio-elements are isotopes of the co-prec ip i t a tor s or of one other element, of the s e r i e s . For example, of the r a d i o - elements co-prec ip i ta ted with bismuth, the C and E products, <^  isotopes of bismuth, the remainder are isotopes of polonium. The very short l i v e d " C " products of tha l l ium need not be removed. Table 1 Co-Prec ip i t a t i on of the Radio-Elements (9) Element added and prec ip i t a t ed Radio-elements p rec ip i t a t ed as isotopes or co-prec ip i t a ted Ce (as oxalate) B i (as sulphide) Pb (as sulphide) Ba (as sulphate) Fe (as Hydroxide) Io UX UY—Ac R a A c — T h MsTh? RaTh RaA RaC RaC RaE Po—-AcA ACC A c C — ThA ThC T h C RaB RaD AcB ThB Ra—AcX—MsTh. ThX U-238 U234 U-^35 10 EXPERIMENTAL" E v a l u a t i o n of R e s i n . A simple experimental column, as i l l u s t r a t e d i n f i g u r e 1, was c o n s t r u c t e d t o t e s t the performance of the exchange r e s i n , Amberlite 120, and a l s o t o o b t a i n s u f f i c i e n t data t o c o n s t r u c t a l a r g e r column f o r our a c t u a l d e t e r m i n a t i o n of uranium i n sea water. A g l a s s column 1.5 inches i n diameter and 10 inches long w i t h a medium porous p l u g which Amost con v e n i e n t to handle and a f f o r d e d e x c e l l e n t v i s i b i l i t y was used f o r these p r e l i m i n a r y experiments. The s i n t e r e d - g l a s s p l u g prevented entrainment o f r e t e n t i o n o f regenerant or o t h e r s o l u t i o n s . In such a column, packing and channeling o f the r e s i n was avoided. A T-tube was attached to t h i s column by means o f a rubber j o i n t and each p r o j e c t i n g p a r t of t h e T-tube was f i t t e d w i t h a p i e c e of rubber t u b i n g and a Hoffman screw clamp f o r r e g u l a t i o n o f f l o w a t the d e s i r e d r a t e . A stopper at the top f i t t e d w i t h a three-way T-tube as i l l u s t r a t e d i n f i g u r e 1 completed the apparatus. The arms of t h i s T-tube p r o v i d e d f o r escape o f e f f l u e n t i n back-wash or upflow opera t i o n s , and f o r entrance of exhausting s o l u t i o n s i n downflow o p e r a t i o n . Connections to the upper T-tube were c o n t r o l l e d by means of p i n c h clamps and when any one of these were r e  moved, the downflow r a t e was; c o n t r o l l e d by the Hoffman clamp a t the bottom of the column s e r v i n g as an o u t l e t . A s t r i p o f r u l e d or c o o r d i n a t e paper was pasted 11 along the s i d e , the column was c a l i b r a t e d c o n v e n i e n t l y i n terms o f l i n e a r s c a l e u n i t s by p i p e t t i n g s u c c e s s i v e 10 m i l l i l i t e r samples o f water on top of t h e g l a s s p l u g and the s c a l e r e a d i n g of the meniscus was recorded each time. T h i s was done a f t e r the bottom o f the column had been f i l l e d w i t h water up t o the pl u g w i t h the clamps of the T-tube c l o s e d . From t h i s data an average "column f a c t o r " , the number by which the h e i g h t o f a s e c t i o n o f column must be m u l t i p l i e d t o g i v e i t s volume, was o b t a i n e d . R e s i n bed volumes i n m i l l i l i t e r s w e r e then c a l c u l a t e d d i r e c t l y from the product of the number of s c a l e u n i t s between the l i m i t s o f the bed and t h i s column f a c t o r . Two r e s e r v o i r s were r e q u i r e d , one as a source o f s o l u t i o n to be t r e a t e d , and the o t h e r t o f u r n i s h regenerant f o r the r e s i n . Since the flow must be c o n t r o l l e d a c c u r a t e l y , the s o l u t i o n s were f o r c e d to the top of the column by corn ed pressed a i r under a co n s t a n t pressure maintain^by a T-tube arrangement i n mercury as shown i n f i g u r e 1, Ambe r l i t e 120 c o n t a i n e d s u f f i c i e n t moisture so t h a t t h e r e was r e l a t i v e l y l i t t l e s w e l l i n g upon w e t t i n g . Thus a g i v e n d e s i r e d volume was measured out d i r e c t l y b e f o r e i n t r o d u c t i o n i n t o the column u s i n g the exchanger as r e c e i v e d . The r e s i n was s l u r r i e d f i r s t i n a beaker and washed i n t o the column through a f u n n e l . A f t e r the column was charged as d e s c r i b e d , the column was washed a t a r a t e s u f f i c i e n t t o cause 50 to 70 percent bed expansion. T h i s was done i n o r d e r to 12 F i g u r e 1. EXPERIMENTAL COLUMN. Pinch clamps NOTATION FOR FIGURE 1 —-EXPERIMENTAL COLUMN 1. Exhaust S o l u t i o n . 2. D r a i n 3. Rinse 4. L e v e l c o n t r o l 5. Ion-exchange r e s i n - Amberlite IR-120 6. Porous pl u g 7 . E f f l u e n t 8. Backwash 9. Regenerant 10. Compressed a i r 11. Regenerant s o l u t i o n remove the f i n e s which remain i n the r e s i n s when shipped. T h i s r e s i d u e was removed t o prevent e x c e s s i v e r e s i s t a n c e t o downflow o p e r a t i o n . The backwash was continued u n t i l the f i n e s had been washed from the bed. I n the g l a s s column technique i t was simple t o observe when t h i s c o n d i t i o n had been reached and prevent.; i. the l o s s of the l a r g e r p a r t i c l e s by proper f l o w r e g u l a t i o n . The proper backwash caused the r e s i n p a r t i c l e s t o move up and down f r e e l y w i t h i n the bed and t h i s served t o c l a s s i f y the bed h y d r a u l i c a l l y i n i n c r e a s i n g p a r t i c l e s i z e from top t o bottom. Such a c l a s s i f i c a t i o n improved o p e r a t i n g c h a r a c t e r i s t i c s o f the r e s i n . The backwash which prevented packing o f the r e s i n , was c a r r i e d out u s i n g d i s t i l l e d water and backwashing was repeated a f t e r each exhaustion c y c l e . When t h e backwash was completed, i t was necessary t o determine the bed volume upon which c a p a c i t y data were c a l c u l a t e d . I t has been demonstrated t h a t r e p r o d u c i b l e bed volume r e s u l t s c o u l d be ob t a i n e d by a d r a i n i n g the bed f o l l o w i n g backwash t o ^ g i v e n h e i g h t o f water above the r e s i n , u s u a l l y chosen as one i n c h . The bed volume was then determined from the column c a l i b r a t i o n as p r e v i o u s l y e x p l a i n e d . The r e s i n was allowed to s e t t l e by g r a v i t y before d r a i n i n g was begun and a l l bed volumes r e f e r r e d t o w i l l be t h i s backwashed and d r a i n e d bed volume. The fl o w r a t e a t which t h i s d r a i n i n g was c a r r i e d out i s r e l a t i v e l y c r i t i c a l because the water must not run out f a s t enough t o cause ex- 14 c e s s i v e s e t t l i n g and hence pack the r e s i n bed. The bed was never a l l o w e d t o d r a i n dry as t h i s would cause a i r pockets t o appear i n the bed causing subsequent f a u l t y c o n t a c t o f t h e exhausting or r e g e n e r a t i n g s o l u t i o n w i t h the r e s i n and l i m i t i n g exchange. Moreover, i t was d e s i r a b l e t o have a s m a l l amount of water above the bed to cushion the incoming stream dur i n g the e x h a u s t i o n c y c l e and thus p r e  vent the bed from being d i s t u r b e d e x c e s s i v e l y . The column was operated downflow by running the exhausting s o l u t i o n through the r e s i n from top t o bottom. The extent to which the m a t e r i a l being exchanged i s removed depends p r i m a r i l y upon the q u a n t i t y o f r e g e n e r a t i o n m a t e r i a l used and the composition of the exhausting s o l u t i o n , and s e c o n d a r i l y upon the exhausting s o l u t i o n f l o w r a t e per u n i t volume o f exchanger. The q u a l i t y d e s i r e d i n the t r e a t e d e f f l u e n t i s the f a c t o r which determines the l e n g t h o f time between r e g e n e r a t i o n s f o r any g i v e n r e g e n e r a t i o n v a l u e . The t o t a l exchange o f d i v a l e n t or h i g h e r valence i o n s are d e s i r a b l e and t h e r e f o r e i t was necessary to regenerate our r e s i n t o the l e v e l which gave the optimun c a p a c i t y . To determine t h e v a r i a t i o n of c a p a c i t y w i t h v a r i o u s sodium i o n c o n c e n t r a t i o n s , s o l u t i o n s o f .1 e q u i v a l e n t s i n copper i o n s per l i t e r w i t h v a r i o u s c o n c e n t r a t i o n s o f sodium c h l o r i d e were run through the s m a l l experimental column j u s t d e s c r i b e d . Each s o l u t i o n was run through the column a f t e r the u s u a l s t e p s of r e g e n e r a t i o n and backwash e t c . The exchanger e f f l u e n t was sampled from time t o 15 time with Na2S to detect the f i r s t leakage of copper ions and the volume of the exhausted solution was noted when the f i r s t leakage was detected. This procedure was repeated for three samples of the same solution and in each case the results were in perfect agreement. The capacity was found to decrease rapidly with increasing concentrations of sodium ions in the exhaust solutions as expected. The data obtained in this experiment i s given in table 3 and a plot of this i s shown in figure 2. From such a plot, and knowing the desired total bed capacity for our subsequent determination of uranium in sea water, the volume of resin to be employed may therefore be easily found. The following table (Table 2) gives the operating conditions of our small column as specified by the producers of Amberlite 120, (10) Table 2. Operating Specifications for - Amberlite 120 120cc 10$ 15.9cc/min. 13,7Meq./cc resin,.or S66cc(10^sdn. 15.9cc/min. 800cc 31.8cc/min. .197 equiv. Volume of Resin Regenerant concentration Regenerant flow rate Regenerant level Rinse flow rate Rinse water requirement Service flow rate Capacity 16 F i g u r e 2. THE CAPACITY OF AMBERLITE IR-120 vs SODIUM CONCENTRATION. (Meq./cc vs $ Na by weight) V a r i a t i o n T a b l e 3. of C a p a c i t y w i t h Sodium Ion C o n c e n t r a t i o n Cone, o f Cu + e q u i v . / l i t e r Cone, o f Na+ % by weight Max. V o l . o f exhaust s o l n . C a p a c i t y Meq,/cc r e s i n .1 0.0 1990cc 1.66 .1 0.39 1000cc 0.833 .1 0.50 900cc 0.750 .1 1.0 325cc 0.541 A n a l y s i s o f Sea Water Sample In order t o determine as a c c u r a t e l y as p o s s i b l e the maximum volume of sea water s u f f i c i e n t t o j u s t exhaust the r e s i n , a n a l y s i s o f the sea water sample must be performed. Of the major c a t i o n c o n s t i t u e n t s of sea water, magnesium and c a l c i u m comprise the g r e a t e s t p o r t i o n o f the d i - v a l e n t and hi g h e r v a l e n c e i o n s (11). As has a l r e a d y been s t a t e d , i t i s the d i - v a l e n t and h i g h e r valence i o n s which are exchanged i n the sodium c y c l e . Consequently, the exhaustion o f our column i s t o t a l l y dependent upon the c o n c e n t r a t i o n o f ca l c i u m and magnesium i o n s and a l s o the sodium and potassium i o n c o n c e n t r a t i o n s which determine the c a p a c i t y o f the column. I t has been found t h a t the sodium, potassium, c a l c i u m and magnesium i o n c o n c e n t r a t i o n s may be e a s i l y found once the c h l o r i n i t y i s known and the f o l l o w i n g r a t i o s as giv e n i n t a b l e 4 are found t o h o l d . The c h l o r i n i t y was found by the Vol h a r d t i t r a t i o n w i t h s i l v e r n i t r a t e and the c h l o r i n i t y was found t o be 16.383. Table 4 g i v e s the v a r i o u s 17 major constituents i n our sample of sea water. Table 4. Ma.jor Constituents i n Sea Water Sample Ion Ratio to C h l o r i n i t y Weight i n gms./l Equiv./l Na+ .5509 9.27 K + .0200 0.334 Mg+* .06695 1.12 0.0922 Ca + + .02106 0.352 0.01755 The above data also supplied enough information f o r us t o make up a r t i f i c i a l sea water f o r our control determinations with conditions very s i m i l a r to those found i n the actual sample. The C.P. s a l t s of sodium, potassium, magnesium and calcium were used and the amounts used per l i t e r of s o l u t i o n were as follows: Table 5. Salt Weight gms./l NaCl 23.6 MgCl 2H 20 9.38 Ca(N0 3 ) 2 4 H 20 2.07 KC1 0.638 For the separation of uranium from sea water a new column was constructed consisting mainly of three pyrex glass tubes each 6cm. i n diameter and 124 cm. i n length. To allow f o r a glass wool plug and sand to cushion the r e s i n bed and 18 and t o a l l o w f o r s u f f i c i e n t expansion o f the r e s i n bed i n the backwash o p e r a t i o n , the a c t u a l r e s i n bed was o n l y 75cm. i n h e i g h t . The t o t a l volume o f the r e s i n i n the t h r e e columns was t h e r e f o r e 6 ,360 c c . A diagram o f t h i s column i s g i v e n i n f i g u r e 3 . The c a p a c i t y per c c . o f r e s i n at the sodium i o n c o n c e n t r a t i o n o f 0 . 9 2 4 $ i s 0 . 5 6 0 m i l l i e q u i v a l e n t per c c . r e s i n as determined from the graph and t a b l e 4 . The t o t a l e q u i v a l e n t s of magnesium and c a l c i u m per l i t e r from t a b l e 4 i s 0 . 1 1 0 . The f o l l o w i n g t a b l e (Table 6) g i v e s the opera t i n g s p e c i f i c a t i o n s o f our new column. Table 6 . O p e r a t i o n a l S p e c i f i c a t i o n s f o r 6 , 3 6 0 cc Amberlite IR -120 Cone, o f Na i n exhaust s o l n . 0 . 9 2 4 $ T o t a l r e s i n c a p a c i t y 3.57 e q u i v . Max. v o l . of exhaust s o l n . 3 2 . 4 l i t e r s Exhaust s e r v i c e f l o w r a t e 80 cc/min. Regenerant cone. 20$ (approx.) Regenerant flow r a t e 80 cc/min. Regenerant l e v e l 11.25 l b . Rinse requirement 85 .5 l i t e r s Backwash time requirement 10 min. The S e p a r a t i o n of Uranium From Sea Water I n A a c t u a l run ( 5 ) a f t e r the u s u a l p r e p a r a t i o n s of r e g e n e r a t i o n and washings of t h e r e s i n bed, the samples were pumped through the column from a 40 l i t e r carboy/ by compressed 19 F i g u r e 1. EXCHANGE COLUMN. O Compressed] A A i r Exhaust Regene S o l u t i c or l i i n t us Sand G l a s s Wool a i r regulated by a safety valve, A. The actual route of the samples through the column was as indicated i n diagram 3. After 30 l i t e r s had been run through the column, instead of 32.4 l i t r e s allowing for a safety margin, the column was back- washed with pure water for five minutes and then drained u n t i l the surface of the liquid in column 1 was just that of the resin bed. This was done by regulating valvesB, B1 and B". The eluting agent, 100 cc of 25% sodium cyanide solution, was""" allowed to run through the column at the rate of 50 cc per minute. The resin bed was always submerged in water by ad mitting water on top of the cyanide solution at 50 cc per minute. In this way the cyanide solution was in between two water layers i n going through the column. The f i r s t eluent was collected when cyanide was detected by fer r i c chloride and collecting was continued u n t i l no cyanide could be detected by fe r r i c chloride after which another 100 cc was collected. In this way, approximately 1600 cc was collected each ruru A total of four runs were made two controls and two sea water samples. Treatment of the Eluent. The solutions were then evaporated to 150 cc and cooled. Then 250 cc of concentrated sulfuric acid was added to each of the solutions and evaporated to dryness to decompose the cyanide complexes (14). The treatment in concentrated sulfuric acid was accomplished in porcelain casseroles placed in an, inclined position over the flame, and the flame directed against the upper part of the crucihle. The heating was caan- tinued until Afumes of sulfuric acid ceased to come off. The 21 r e s i d u e c o n s i s t e d o f the a l k a l i s u l f a t e and anhydrous heavy metal s u l f a t e s and u r a n y l s u l f a t e . T h i s r e s i d u e was heated g e n t l y w i t h 10 cc o f conc e n t r a t e d s u l f u r i c a c i d and water was added l i t t l e by l i t t l e u n t i l 25 t o 30 cc was added and the s u l f a t e s were r e a d i l y brought i n t o s o l u t i o n . I t i s presumed the f o l l o w i n g r e a c t i o n took p l a c e ; K 4 ( U 0 2 ( C N ) 6 ) -t 6H2S04+ 6 H 2 0 i f - > 2 K 2 S 0 4 + ( U 0 2 ) S 0 4 + 3 ( N H 4 ) 2 S 0 4 + 6 C 0 2 cc o f one normal f e r r i c c h l o r i d e and 2 cc o f one normal aluminum c h l o r i d e were added t o each s o l u t i o n and the s o l u t i o n s heated up t o b o i l i n g . Ammonium hydroxide was c a r e  f u l l y added t o n e u t r a l i z e the s u l f u r i c a c i d and f i n a l l y t o p r e c i p i t a t e the aluminum and f e r r i c hydroxides which would co- p r e c i p i t a t e any uranium. T h i s c o - p r e c i p i t a t i o n procedure was repeated twice t o ensure complete removal o f uranium. T h i s p r e c i p i t a t e was washed w i t h a d i l u t e s o l u t i o n o f ammonium c h l o r  i d e and the p r e c i p i t a t e f i n a l l y d i s s o l v e d i n p u r i f i e d hydro c h l o r i c a c i d and the s o l u t i o n t r e a t e d by the f o l l o w i n g co- p r e c i p i t a t i o n t e c h nique. 22. A n a l y t i c a l Procedure. The chemical s e p a r a t i o n o f uranium, which i s shown s c h e m a t i c a l l y i n t a b l e 7 i s adapted from the procedure g i v e n by U r r y i n h i s procedure^ f o r the a n a l y s i s of, rock samples (15). Table 7. P r e p a r a t i o n o f Uranium Free from Other Radio-elements. O x i d i z e Fe i n the f i l t r a t e w i t h HNO3. Evaporate t o drynes s . Dissove i n HCl. P r e c i p i t a t e from the b o i l i n g s o l n . w i t h NRYOH i n s l i g h t excess, Fe, Ja, U, Rare E a r t h s , Th, Zr, T l , some Mn e t c . Dissove ppt. i n H C l . Add 20 mg. Ce as Ce (N0 , - ) , Evaporate i n HCl and HNOoJ D i s s o l v e i n s m a l l e s t amount o f HCl ana make up the v o l . t o 150cc. P r e c i p i t a t e w i t h a s a t u r a t e d s o l n . o f O x a l i c a c i d , s t i r v i g o r o u s l y and a l l o w t o stand o v e r n i g h t . F i l t e r and d i s c a r d ppt. o f Ce, Th, Io, Ac. With the f i l t r a t e twice repeat the treatment w i t h Ce. Evaporate the f i n a l f i l t r a t e w i t h HNOo to remove o x a l a t e s , Remove HN0-> by ev a p o r a t i o n w i t h H C l . D i s s o l v e i n h$ HCl. Add 10 mg. each o f B i , Pb, and Ba as c h l o r i d e s . P r e c i p i t a t e the Ba (with some Pb) w i t h a few drops o f a Sa t d . s o l u t i o n o f K ^ S O i . Allow t o stand sxx hours w i t h f r e q u e n t s t i r r i n g and p r e c i p i  t a t e B i and Pb w i t h H 2S. F i l t e r and d i s c a r d ppt. of B i , Pb, Ba. With the f i l t r a t e , twice repeat the treatment w i t h B i , Pb, and Ba, removing the HgS between treatments. To expel the H~S and o x i d i z e the Fe i n the f i n a l f i l t r a t e w i t h HN0 3. c Evaporate to drynes s . D i s s o l v e i n HCl and p r e c i p i t a t e w i t h NH^OH i n s l i g h t excess from the b o i l i n g s o l u t i o n ; Fe, A l , U, e t e . F i l t e r and dry the pp t . o f Fe, A l , U. e t c . 2 3 . The sequence i n which the c o - p r e c i p i t a t o r s are added i s i m  p o r t a n t . For example, were the bismuth and l e a d t o be added p r i o r t o the cerium p r e c i p i t a t i o n , i t i s p o s s i b l e t h a t the cerium and l a t e r the barium would r e - i n t o d u c e the r a d i o - e l e  ments removed by the bismuth and l e a d . In a l l cases i t was important t o use the same quant i t i e s o f reagents as f a r as p o s s i b l e and the treatment o f each s o l u t i o n was e x a c t l y i d e n t i c a l so t h a t our c o r r e c t i o n as determined by our c o n t r o l t e s t s may be a p p l i c a b l e . Exact volumes o f standard s o l u t i o n s o f the c o - p r e c i p i t a t o r s were used by adding each one w i t h i t s i n d i v i d u a l b u r r e t t e . P r e p a r a t i o n s o f the Reagents, (see p. 33. f o r d e t a i l s ) The water was from the l a b o r a t o r y s t i l l . H y d r o c h l o r  i c and n i t r i c a c i d s were d i s t i l l e d from c o n s t a n t - b o i l i n g mixtures of the "Reagent" a c i d s C e r i u m n i t r a t e was p u r i f f e i by d i s s o l v i n g the CP s a l t s i n d i s t i l l e d water and p r e c i p i t a t  i n g the hot s o l u t i o n w i t h o x a l i c a c i d . The p r e c i p i t a t e was d i s s o l v e d i n c o n c e n t r a t e d d i s t i l l e d n i t r i c a c i d and evaporated „ t o dryne s s . The p r e c i p i t a t i o n procedure w i t h o x a l i c a c i d was then repeated twice and c r y s t a l s r e c r y s t a l l i z e d t h r e e t i m e s . Bismuth; l e a d , and i r o n were p r e c i p i t a t e d t h r e e times as s u l  f i d e t o remove the i r o n group s i n c e they must not c o n t a i n Th, Io and Ac i n a d d i t i o n to uranium. The s u l f i d e s were d i s s o l v e d by b o i l i n g w i t h p u r i f i e d n i t r i c a c i d and a f t e r f i l t e r i n g o f f the f r e e s u l f u r , the n i t r i c a c i d was b o i l e d o f f i n h y d r o c h l o r i c a c i d and the r e s u l t i n g c h l o r i d e s a l t s r e c r y s t a l l i z e d t h r e e t i m e s . Barium c h l o r i d e was r e c r y s t a l l i z e d t hree times by s o l - 24 u t i o n i n d i s t i l l e d water. The potassium sulphate was r e c r y s t - a l l i z e d f o u r t i m e s . R a d i o a c t i v e Measurement with N u c l e a r Emulsions. The n u c l e a r emulsion r e c o r d s t r a c k s o f a l l a l p h a p a r t i c l e s t h a t e n t e r the r e c o r d i n g medium p r o v i d e d t h a t t h e i r r e s i d u a l energy exceeds a minimum v a l u e . Although the t r a c k s of minimum d i s c e r n i b i l i t y vary w i t h t h e emulsion composi t i o n , s e n s i t i v i t y , and the m i c r o s c o p i c r e s o l u t i o n , i t i s un necessary to c o n s i d e r t h e complex v a r i a t i o n i n i o n i z i n g power a l o n g t h e t r a j e c t o r y and t h e e f f e c t i v e a r e a o f t t h e counting chamber which a r e important f a c t o r s i n e l e c t r o n i c c o u n t i n g instuments. T h i s s i m p l i f i e s the t r a n s l a t i o n o f the m i c r o s c o p i c a l l y determined t r a c k count i n t o a d i s i n  t e g r a t i o n r a t e , as each t r a c k i r r e s p e c t i v e of l e n g t h c o r  responds to the emission o f an a l p h a p a r t i c l e by the s o u r c e . The processed p l a t e c a r r i e s a r e c o r d of the number o f t r a c k s and a l s o e x h i b i t s t h e i r approximate l i n e of i n c i d e n c e i n t o the o r i g i n a l emulsion. From p u r e l y geometric c o n s i d e r a t i o n s p a r t i c l e s e n t e r i n g the emulsion a t r i g h t a n g l e s should a p p e a r di m e n s i o n l e s s . However, a f t e r f i x a t i o n the g e l a t i n d r i e s to a v e r y t h i n l a y e r and the v e r t i c a l t r a c k s become d i s  t o r t e d . The v i s i b i l i t y o f t h e s e e r e c t t r a c k s i s f u r t h e r enhanced under d a r k - f i e l d i l l u m i n a t i o n by the/light s c a t t e r e d from the compressed column of s i l v e r g r a i n s . With t h i n 2 sources weighing l e s s than 1 mg. per cm ., over 90% o f the p a r t i c l e s e n t e r the emulsion w i t h e n e r g i e s and o r i e n t a - (18) t i o n f a v o r i n g optimum t r a c k v i s i b i l i t y . A Tracks of alpha 25 p a r t i c l e s t h a t spent the g r e a t e r p a r t of t h e i r energy i n t r a v e r s i n g the source are the most d i f f i c u l t t o d i s c e r n b e - cause o f t h e i r s h o r t recorded l e n g t h . A r a d i o a c t i v e source i s c o n s i d e r e d t h i n when i t s e f f e c t i v e t h i c k n e s s , which i s the t h i c k n e s s o f the source i n e q u i v a l e n t a i r - c e n t i m e t e r s , i s l e s s than the e f f e c t i v e mean range of al p h a p a r t i c l e system i n d r y a i r at 15°C. The mechanical t h i c k n e s s or weight per u n i t area v a r i e s w i t h the p e r m e a b i l i t y of the c a r r i e r but w i l l i n g e n e r a l r e s i d e below 2 2 mg. per cm. In our d e t e r m i n a t i o n the sample t h i c k n e s s l i e s w e l l below t h i s value and may t h e r e f o r e be c o n s i d e r e d a " t h i n " source. Geometric c o n s i d e r a t i o n s , the d e t a i l s of which are d i s c u s s e d by Evans (16, 17) i n c o n j u n c t i o n w i t h alpha pulse counter, show t h a t : 2 n r d = , . » n r k w I _ T -2L ' 2(R-p) where: d i s the number of d i s i n t e g r a t i o n s i n the source d u r i n g exposure. n r i s the t o t a l number of t r a c k s r e c o r d e d d u r i n g exposure. T i s the t h i c k n e s s of the source i n e q u i v a l e n t a i r - c e n t i m e t e r s . L i s the d i s t a n c e between source and emulsion i n a i r - c e n t i m e t e r s , p i s the t r a c k l e n g t h i n a i r - c e n t i m e t e r s of minimum d i s c e r n i - b i l i t y . R i s the e f f e c t i v e mean range o f alpha p a r t i c l e system i n dry a i r a t 15°C. I t i s e v i d e n t from t h i s e quation t h a t L i s an important f a c t o r i n governing the p r o p o r t i o n of alpha - r-particle t r a c k s recorded by the emulsion. Yagoda has computed several, v a l u e s of k f o r v a r i o u s r a d i o a c t i v e compounds (18). The 26 tracks are distributed at random, and, when L is about 0.05 air-cm., 98$ of the tracks are confined to an area of the same dimensions as the source, n was therefore determined i n - r directly by a restricted count on representative areas of the emulsion. samples were made with Eastman NTB plates with emulsion thick ness of 100 microns. The hydroxides were ignited to form the oxides and were ground to a powder in their respective crucibles. Each sample was sprinkled onto an adhesive sur face bordered by an aluminum frame 0.05 cm. thick and leaving 2 an exposed adhesive area of 10.0 cm. . The sample was sprink led in excess onto the adhesive surface to cover the entire surface after which the excess was removed by gentle tapping with the surface inverted. The nuclear track plate was then placed over the sample and clamped to commence the exposure. In this way the sample was "thin" and kept at a known distance from the track plate. This arrangement i s illustrated in figure 4. The actual recording of the activity in our FIGURE 4. —Clamp Nuclear emulsion Sample on adhesive surface rFrame 27 Because the samples were expected t o be very- weak, the exposure was f o r 2^2 hours. The development of the p l a t e s were done a c c o r d i n g t o i n s t r u c t i o n s from the Eastman Kodak p u b l i c a t i o n (19). The t r a c k s were counted under d a r k - f i e l d i l  l u m i n a t i o n u s i n g a 45X dry o b j e c t i v e whose ape r t u r e was r e  duced by s u i t a b l e d a r k - f i e l d s t o p s . The r e d u c t i o n o f the apert u r e i s of paramount importance i n q u a n t i t i v e t r a c k count i n g . I t i n c r e a s e s f o c a l depth so t h a t a l l t r a c k s , i r r e s  p e c t i v e of t h e i r p o s i t i o n i n the g e l a t i n l a y e r , are brought i n t o view w i t h one f o c a l s e t t i n g . When the exposure i s made wi t h an e x t e r n a l source the t r a c k s r e s i d e c l o s e t o the upper surface, o f the g e l a t i n . The t r a c k s were counted i n a r e s  t r i c t e d a r e a o f the microscope f i e l d w i t h the a i d o f a graduated o c u l a r diaphragm. With the use o f such a d i a - phragm a l l the t r a c k s were counted along a s t r i p which ex tended from one s i d e of the t r a c k p l a t e to the o t h e r . 28 RESULTS. The r e s u l t s o f our experiments are as enumerated i n Table 8. The t r a c k s were counted as p r e v i o u s l y d e s c r i b e d and the u n c e r t a i n t y i n the count i s 2.3% as suggested by Yagoda (20) The c o r r e c t i o n f a c t o r was determined from the r e s u l t s o f the c o n t r o l t e s t s . The a c t i v i t y of the 15 cc o f s o l u t i o n was 3.71*106 ±.085*10 6 but the c o n t r o l r e s u l t s were 2.07*106 ±.0476'10° and 2.02 ,10 6±.0465*10 6. The r e s u l t s o f the c o n t r o l s v a r i e d from the t o t a l added amount by f a c t o r s o f 1.78" and 1.83 r e s p e c t i v e l y and y i e l d i n g an average f a c t o r o f 1.81. Table 8. THE DETERMINATION OF THE URANIUM CONTENT FROM THE RADIOACTIVE MEASUREMENTS. ^ Sample Sample volume ( l i t e r s ) T o t a l weight o f o x i d e s . Weight o f oxide examined. Alpha p a r t i c l e s counted f o r 2Li h r s . (10*) Sea water A 30 .7246 .0280 1.29 ±.0196 Sea water B 30 .2868 .0310 1.71 +.039 C o n t r o l A 30 .2393 .0174 6.93 +.140 C o n t r o l B, 30 .2550 .0195- 7.11 +.164 Sample T o t a l counts f o r _ 2 4 i h r s . (105). Uranium g. ger g. (10 5)sea water. C o r r e c t i o n f a c t o r . Uranium g./g. (10 ) sea water c o r r e c t e d Sea water A 7.21 ±.166 2.19 1.81 3.93 Sea water B 3.44 ±.07^ 1.05 1.81 1.90 C o n t r o l A 20.7 +.476 6.32 1.81 11.45 C o n t r o l B 20.2 ±.465 6.17 1.81 11.10 The k value used was 2.17 (18). w 29 A CONCLUSIONS The c o n t r o l t e s t s i n d i c a t e t h a t s m a l l q u a n t i t i e s o f uranium can be s u b j e c t e d to the complex chemical processes o f s e p a r a t i o n without a p p r e c i a b l e l o s s . I n both c o n t r o l t e s t s the r e s u l t s were i n v e r y s a t i s f a c t o r y agreement although the r e s u l t s i n d i c a t e a l o s s of uranium. Incomplete removal by c o - p r e c i p i t a t i o n o f any o t h e r radio-elements t h a t emit a l p h a - p a r t i c l e s r e s u l t s i n g r e a t e r a c t i v i t y . But, incomplete exchange and e l u t i n g processes along w i t h i n e f f i c i e n t co- p r e c i p i t a t i o n s may l e a d t o low r e s u l t s . However, the r e s u l t s are open t o c r i t i c i s m because a l o s s of uranium might con c e i v a b l y be e x a c t l y compensated by incomplete removal of the o ther radio-elements although there seems to be no reason t o doubt the e f f i c i e n c y o f the c o - p r e c i p i t a t i o n s which have been so w e l l e s t a b l i s h e d i n r a d i o - c h e m i s t r y . Our r e s u l t s f o r sea water of 3 . 9 8 ' 1 0 and 1 .9*10 grams per gram o f sea water - 9 i s h i g h e r than t h a t found by K a r l i k whose value was 1 .3*10 . The d i f f e r e n c e between the two r e s u l t s f o r sea water cannot be f u l l y e x p l a i n e d but the s o l u t i o n s were handled w i t h g r e a t care and i d e n t i c a l l y . T h i s i s shown i n the c o n t r o l t e s t s which r e s u l t s were w i t h i n 3 . 0 $ agreement. The sea water as shipped from the P a c i f i c Oceanographic Labs i n two s t e e l drums and the two samples of the sea water which were run through the column were from two d i f f e r e n t drums. As was a l r e a d y s t a t e d , f i l t e r i n g was r e q u i r e d and i t was n o t i c e d t h a t the r e s i d u e or s o l i d i m p u r i t i e s thus separated were com posed of b l a c k s o l i d s and/"reddish brown s o l i d matter, the 29 B l a t t e r t a k e n f o r r u s t . T h i s r e s i d u e was found to be pres e n t i n the samples even though they were withdrawn from the drums w i t h i n two days upon a r r i v a l . I f r u s t was present i n the sea water samples, the uranium may p o s s i b l y have been occluded or c o - p r e c i p i t a t e d by the r u s t . T h i s i s u n c e r t a i n but the c o - p r e c i p i t a t i o n of uranium by f e r r i c hydroxide s t r o n g l y suggests t h i s p o s s i b l i t y . Although the two sea water d e t e r m i n a t i o n s d i f f e r by a f a c t o r of 2.1, the r e s u l t s were c o n s i d e r e d s a t i s f a c t o r y i n view o f the magnitude of the c o n c e n t r a t i o n . SUGGESTIONS FOR FUTURE WORK Our s e p a r a t i o n o f the micro-amounts of uranium from sea water has provided another method f o r the determina t i o n o f other micro-elements i n the sea. Since the t r a c i n g of the v a r i o u s members of the radio-elements i n the uranium f a m i l y i n the sea has not been determined c o n c l u s i v e l y , such i n v e s t i g a t i o n s would present very i n t r i g u i n g problems to the chemist and g e o - p h y s i c i s t . Although many determinationson the radium content of marine l i f e and bottom sediments have been made by Evans (21) from P a c i f i c ocean samples, i t has not e s t a b l i s h e d where the v a r i o u s q u a n t i t i e s are d i s t r i b u t e d i n the sea and surroundings. Foyn, et a l . (22) had found t h a t . , -16 the radium content o f sea water was .86'10 grams of radium -12 per cc of water as compared t o .46*10 grams of radium per gram of p l a n k t o n as found by Evans. However, t h e r e i s some evidence r e l a t i v e t o the p o s s i b l e chemical e x t r a c t i o n of 30 c a l c i u m by marine organisms. From K a r l i k ' s (5) d e t e r m i n a t i o n of uranium -9 i n sea water an average o f 1.3*10 grams per gram o f sea water was found but the radium content as found by Foyn was -6 o n l y 0.8*10 grams per granr of water. I f t h i s l a t t e r amount i s c o r r e c t then .24*10"^ grams o f uranium per gram of water c o u l d support t h i s amount. Instead, however, we have f i v e times as much uranium as necessary t o m a i n t a i n the radium content. On the otherhand i t was found by U r r y (9) t h a t bottom samples o f h i g h radium content had about one q u a r t e r as much uranium as necessary t o support i t s radium co n t e n t . The r a t e o f d e p o s i t i o n i n the deep ocean i s about one c e n t i m e t e r per 1,000 years and t h e r e f o r e the uranium and radium may not be i n e q u i l i b r i u m but whatever the sedimenta t i o n process i s , i t must be e f f i c i e n t , s i n c e h i g h c o n c e n t r a  t i o n bottom samples contain tens of thousands of times as much radium per u n i t weight as does the ocean water. I t must be remembered t h a t the p r e c i p i t a t i o n of f e r r i c hydroxide i s a method f o r p r e c i p i t a t i n g ionium and uranium from d i l u t e s o l u t i o n s and such a process might c o n c e i v a b l y o c c u r . I t has been observed by Thompson, et al . . (23) t h a t the con c e n t r a t i o n o f f e r r i c i r o n i n ocean water i s l e s s than i t should be i f a l l the i r o n r e c e i v e d were h e l d i n s o l u t i o n but the p r e c i p i t a t i o n of uranium would be i n h i b i t e d by the presence o f carbonate i o n s . T h i s c o u l d c o n t r i b u t e t o the means by which the ionium-uranium unbalanoo-in the sea water \ 31 and sediments dcffi unbal&ncejcl. In the p r e c e d i n g d i s c u s s i o n the sea water, marine l i f e and bottom sediments and rocks were not from the same l o c a l i t y and too much emphasis cannot be p l a c e d upon these r e s u l t s as i t i s w e l l e s t a b l i s h e d by Sanderman and Utter b a c k (240 t h a t the radium content o f ocean bottom sediments may vary a p p r e c i a b l y w i t h the l o c a t i o n . T h e r e f o r e , i t should be a very i n t e r e s t i n g p r o j e c t t o determine the d i s  t r i b u t i o n and balance of the radio-elements o f uranium f a m i l y i n the ocean sediments and rocks and the sea water d i r e c t l y above i t by means of an a l y s e s on cored samples and water samples. 32 APPENDIX. The HCL and HNO^ were d i l u t e d w i t h d i s t i l l e d water to the approximate?.constant b o i l i n g compositions before being d i s t i l l e d . The f i r s t and l a s t q u a r t e r of the d i s t i l l a t e were d i s c a r d e d and the middle h a l f was c o l l e c t e d . The compo s i t i o n of the constant b o i l i n g HNO^ was 68f. and f o r the HCl 20.2%. The constant b o i l i n g p o i n t s were 120.5°C and 110°C f o r HNO, and HCl r e s p e c t i v e l y . 33 «A REFERENCES 1. J o l y , J . ; P h i l Mag., 16, 196, 1905. 2. Walker, P.H.; J . Am. Chem. S o c , 20, 513, 1898. 3. d. Carvalho, H; Compt. rend., 191, 95, 1930. 4. Hernegger, F.; A n z e i g . d. Wien. Akad. d. Wissensch. 19,1, 1933. 5. Hernegger, F., & K a r l i k , B., Goteborgs Kungl. Vetenskaps- ock V i t t e r h e t s - S a m h a l l e s Handlingar, Femte F o l j d e n , Serb. B, Band 4, 1935. 6. Urry, Wm. D. Am. J . Sc. 2 3 9 , 191, 1941. 7. K e r r , H.W. J . Am. Soc. Agron. 2 0 , 309, (1928). 8. Hevesy, G., Paneth, F., A manual of R a d i o a c t i v i t y , Oxford Univ. P r e s s . 1926. P. 119. 9. U r r y Wm. D. Am J . Sc. .239, 194, 1941. 10. Rohm. & Haas Co. Amberlite B u l l e t i n IR-120. 11. Sverdrup, H., Johnson, M. Fleming, R. "The Oceans t h e i r P h y s i c s , Chemistry & General B i o l o g y , " P r e n t i c e H a l l I n c . N.Y. 1946. p. 173. 12. Thompson, I.G. & Robinson, R.J. "Nat. Research C o u n c i l " , B u l l . , no. 85, 1932. Wash. D.C. 13 Thompson, I.G. & C.C. Wright. "Amer. Chem. Soc." 3ourn. 52, 915-21, (1930). 14 T r e a d w e l l , H a l l . V o l . 1, Q u a l i t a t i v e A n a l y s i s , John W i l e y & Sons. N. Y. p. 217 (1946.) 15 U r r y Wm. D. Am. J . Sc. 239, 195, 1941. 16. Evans, R.D. & Goodman C. Phys. Rev. 65, 216-227, (1944.) 3 3 B "17. Evans, R.D. & Goodman C. Phys. Rev. 65, 2 1 6 - 2 2 7 , (1944.) 18. Yagoda, H. R a d i o a c t i v e Measurements with Nuclear Emulsions, John Wiley & Sons, Y.Y. p. 118 (1949.) 19. "Photographic P l a t e s f o r S c i e n t i f i c & T e c h n i c a l Use," Eastman Kodak Co., Rochester 4, N. Y. 6 t h E d i t i o n s p. 33. 2 0 . Yagoda, H. R a d i o a c t i v e Measurements w i t h Nuclear Emulsions John W i l e y & Sons, N.Y. p. 119 (1949.) 2 1 . Evans, R.D. K i p , A.F. & Moberg, E.G. Am. J . S c i . 36, 2 4 1 - 2 5 9 , (193$.) 2 2 . Foyn. E., K a r l i k , B. P e t t e r s s o n , H., & Rona.E., Goteborg. Vetensk-samh. Handl. Femte 'Foljden, (B), 6, ( 1 2 ) : 1-44 (1939.) 2 3 . Thompson, T.G., Bremner, R.W., & Jamieson, I.M. Ind. Eng. Chem., A n a l . Ed., 4, ( 1 ) : 288 - 2 9 0 , (1932.) 2 4 . Sanderman, L.A., Utterback, C.L. J.M.R. IV, ( 2 ) , 132, (1941.) 34 ACKNOWLEDGEMENT S i n c e r e s t thanks and a p p r e c i a t i o n t o Dr. J.G. Hooley under whose guidance and s u p e r v i s i o n t h i s r e s e a r c h was undertaken. Tjhanks a l s o t o the P a c i f i c Oceanographic L a b o r a t o r i e s f o r the sea water samples. 35. 

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