Field Determination 

of Uranium in 

Natural Waters

GEOLOGICAL SURVEY BULLETIN 1036-J

Field Determination 

of Uranium in 

Natural Waters

By F. N. WARD and A. P. MARRANZINO

CONTRIBUTIONS TO GEOCHEMISTRY

GEOLOGICAL SURVEY BULLETIN 1036-J

A semiquantitative method for use in 

hydrogeochemical prospecting

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1957
UNITED STATES DEPARTMENT OF THE INTERIOR 

Fred A. Seaton, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington 25, D. C. - Price 15 cents (paper cover)
CONTENTS

Abstract __ _______--______-_-----__, ______-__--_____--_____- _ 181

Introduction _____-____-__----------__-___-_____-____---_____--____ 181

Collection of uranium_-______-_----_______________-_____-____-_-___ 183-

Experiments. _____________________________________________________ 184

Maximum salt concentration _ _________________________________ 184

Effect of EDTA.______________ ___ ____ __ .___-_________--___ 184

Effect of relative humidity on drying of sample aliquots. ___________ 184

Solvent mixtures ____---_------_-_-__-____-______-___-------_-- 186

Reagents and apparatus_____-----___--___-___--_____-_---__-------- 187

Procedure ________________________________________________________ 188-

Results _ ______________ _ ___ _____ _.__ _ _ _ _ _ _______ __ __ 189

Literature Cited_ _ __._.-______ _ ________ _ ___ ___ ______ _ ____ 192

ILLUSTRATIONS

FIGTIKE 18. Filter apparatus______________________________________ 189*

TABLES

TABLE 1. Effect of relative humidity on drying of chromatographic papers_ 18&

2. Effect of water in solvent at 14 and 17 percent acid concentrations on chromatographic separations _____________________ 187

3. Recovery of added uranium______________________________ 190

4. Determination of uranium in binary mixtures________________ 19O

5. Repeatability of uranium determinations____________________ 191

6. Determination of uranium in water_____________-----__--_-_ 191

m

CONTRIBUTIONS TO GEOCHEMISTRY

FIELD DETERMINATION^ URANIUM 

IN NATURAL WATERS

By F. N. WARD and A. P. MAKEANZINO

ABSTRACT

A simple and moderately accurate method for determining traces of uranium 

in natural waters has been devised to facilitate the development of hydrogeochemical prospecting techniques. The procedure eliminates the present practice of transporting bulky water samples from field to laboratory and the timeconsuming evaporation of samples, preliminary to analysis. Under field conditions the uranium is separated from a water sample by means of a phosphate 

collector, and, after a paper-chromatographic separation, is determined by its. 

reaction with ferrocyanide. The lower limit of the method is 2 ppb (parts per 

billion) and without modification it can be used to determine as high as 200' 

ppb of uranium in natural waters. Recoveries of 2, 5, and 10 micrograms of 

uranium added to 500 ml portions of a water sample are respectively 1, 5, and 7 

micrograms. The analyses of 7 different binary mixtures prepared from natural 

water samples compare favorably with the values calculated from the mixturecomposition and the known uranium contents of the components. Five repeat, 

determinations on a water sample containing 5 ppb agree within 1 ppb of themean; similar determinations on a sample containing 30 ppb agree within 4 ppb 

of the mean. Results by the proposed method on samples containing from 2 to 

30 ppb of uranium compare reasonably well with the fluorimetric results obtained, 

by another laboratory of the United States Geological Survey.

INTRODUCTION

A field method for determining traces of uranium in natural waters 

was needed to facilitate uranium exploration by hydrogeoehemieat 

techniques. To date these techniques have been hampered by thelabor involved in collecting enough samples and by the cost of transporting the samples from field to laboratory. Moreover, during the 

time required to transport the samples to the laboratory the metal 

content of the water may change because of adsorption on the inner 

surface of the container or by reaction with the algae which frequently 

develop after the samples are taken, with the result that even the 

most efficient sampling techniques are often nullified.

The term "natural waters" as used in this paper connotes fresh 

water uncontaminated by human activities; the present paper presents a simple means of filtering a sample of such water at the sampling

181
182 CONTRIBUTIONS TO GEOCHEMISTRY

«ite to collect the uranium from the water in a small wad of paper 

pulp and describes a procedure for determining the quantity of collected uranium at either a nearby field station or in a laboratory. 

The collection of the uranium from a water sample in the field by such 

a technique effectively eliminates the labor involved in transporting 

bulky water samples, and the field determination of the collected 

^uranium decreases the cost per analysis to a negligible part of the 

total exploration costs.

The uranium concentration in natural waters commonly ranges 

from a fraction of 1 ppb to a few parts per billion, but in water moving 

through mineralized ground the concentration may reach several thousand parts per billion. Analytical methods useful in exploration by 

hydrogeochemical techniques should cover the entire range above 2 

ppb. Because the actual quantity of uranium that can be detected 

ranges from 1X10~5 gram for colorimetrie to 1X10~10 gram for 

fluorimetric methods (Grimaldi and others, 1954), useful analytical 

methods require some type of collection or other means to concentrate 

the uranium.

In most of the published methods for determining uranium in water 

the collected uranium is measured by the fluorescence of a sodium 

fluoride bead. These measurements require special equipment to 

measure the fluorescence emitted by small amounts of uranium; other

 elements in the water, however, interfere by enhancing or quenching 

the fluorescence. Uranium is usually separated from most of the interfering elements by extraction into ethyl acetate, and is recovered 

after evaporation of the extractant. Fluorescent measurements are 

widely used (Grimaldi and others, 1954) because of their great sensitivity. If enough uranium could be isolated and concentrated, however, other kinds of measurements might be useful.

The chromatographic procedure developed by Hunt, North, and 

IVells (1955) and modified by Thompson and Lakin (1957) seems to 

be another useful way of measuring the uranium. In brief, the uranium in a sample aliquot is dried on a strip of filter paper and then 

moved in a solvent front away from possible interferences from other

 elements, such as iron. The strip is sprayed with aqueous ferrocyatiide to produce a brown-colored band, the color and width of the 

band being proportional to the uranium present. The lowest amount

 detectible by this reaction is about 0.1 microgram.

If the uranium can be collected rapidly and easily from a large 

enough water sample, the chromatographic separation on filter-paper 

strips followed by the reaction with ferrocyanide offers distinct 

advantages over fluorescent measurements, especially under [field 

(Conditions.
FIELD DETERMINATION OF URANIUM IN NATURAL WATERS 183

COLLECTION OF URANIUM

Hecht and others, (1956) employ the strongly basic resin IRA 400 

to collect the uranium from a natural-water sample and to effect a 

separation of the uranium from iron, thorium, and cerium. More 

often traces of uranium in natural waters are collected by precipitation as the hydroxide (Hernegger and Karlik, 1934), (Urry, 1941), or 

the phosphate (Tschernichow and Guildina, 1934) with suitable carriers, such as iron or aluminum. When the uranium is collected as the 

hydroxide or the phosphate, the finery divided and often gelatinous 

precipitate has to be separated from the liquid phase by filtration or 

centrifugation. The slowness of the filtration of gelatinous precipitates precluded their use under field, conditions, and suitable centrifuges cannot be considered field equipment.

In the proposed procedure the uranium is collected in the following 

manner: A saturated solution of dibasic sodium phosphate is added 

to the acidified sample solution until the pH is about 6. The naturalwater samples collected to date, remain clear even after the pH adjustment; however certain mine waters contain enough calcium, aluminum, iron, and other chemical constituents to precipitate under these 

conditions. If any precipitation occurs during the pH adjustment, a 

5 percent aqueous solution of disodium ethylenediaminetetraacetic 

acid (EDTA) is added drop by drop until the precipitate is redissolved. 

When the sample solution so prepared is filtered through paper pulp, 

the paper collects almost all the uranium present. In the absence of 

phosphate, a variable amount but generally less than 50 percent of 

the uranium present will be found in the paper pulp.

The ^resent writers have not made a detailed study of the mechanism of the collection, but the following facts are pertinent: Rodden 

(1950) stated that "even 12 percent nitric acid will not redissolve 

uranyl phosphate," and hi a study of the distribution of uranium 

during an ether extraction process, he recommended ferric or aluminum 

nitrate to complex the phosphate and thus overcome its inhibiting 

influence. Thompson and Lakin were unable to separate the uranium 

from a phosphate rock sample solution on a chromatographic paper 

strip, until they added aluminum nitrate to the sample solution. The 

present writers also observed that, unless the nitric acid used to dissolve the Collected uranium contained a large amount of aluminum 

nitrate, no uranium moved in the solvent front during the subsequent 

chromatographic separation. These facts provide a basis for concluding that in the method proposed here, the uranium is collected as a 

phosphate complex.

The use of aluminum nitrate effectively breaks up the uranium 

phosphate complex and furnishes a high concentration of nitrate ion 

which seems necessary to cause the uranium to move in the solvent 

front.
184 - CONTRIBUTIONS TO GEOCHEMISTRY

EXPERIMENTS

MAXIMUM SALT CONCENTRATION

The phosphate needed to effect complete collection of the uranium 

and the aluminum nitrate needed to break up the uranyl phosphate 

contribute to the salts present in the sample solution prepared for 

chromatographic separation. Large amounts of salts are not only 

difficult to keep in solution, but they inhibit the drying of the sample 

aliquot, and improper drying leads to poor separations. Thus the 

quantity of salts which can be tolerated is limited.

Because the phosphate is added to change the pH through a fixed 

range, the quantity of phosphate present after the uranium collection 

from a natural-water sample is practically constant and cannot be 

decreased appreciably, but the aluminum nitrate may be decreased to 

the minimum amount needed to break up the uranium phosphate 

formed hi the collection step. In order to determine the minimum 

amount needed, 0.2 ml portions of dilute nitric acid solutions (1+3) 

containing from 20 to 90 percent (weight per volume) of aluminum 

nitrate enneahydrate were used to break up the uranyl phosphate 

formed from 5 micrograms of added uranium. The 0.2 ml portion of 

the 80 percent solution effected complete recovery of the added 

uranium.

EFFECT OF EDTA

The disappearance of the yellow-green color of a 0.5 molar sulfuric 

acid solution of uranium standard when EDTA is added indicates the 

formation of some kind of complex. The formation of such a complex 

explains the poor recoveries observed when uranium and EDTA were 

added to samples of demineralized water, and the samples taken 

through the entire procedure. The complex between uranium and 

EDTA must be relatively weak because, in the presence of calcium, 

iron, or aluminum, recoveries of added uranium are satisfactory. 

Presumably these elements form stronger complexes with EDTA and 

inhibit or prevent a reaction between uranium and EDTA. In the 

proposed procedure, EDTA is added only in sufficient quantity to 

redissolve any precipitate of calcium, iron, or aluminum that forms 

during the pH adjustment.

EFFECT OF RELATIVE HUMIDITY ON DRYING OF SAMPLE ALIQUOTS

Before the paper-chromatographic separation, the sample aliquot is 

placed near one end of the paper strip and dried. Proper drying is 

essential for good separation, and suitable conditions were determined 

experimentally.

Hunt, North, and Wells (1955) dried 0.01 and 0.05 ml aliquots in 

the atmosphere for 1 hour, and successfully carried out chromato-
FIELD DETERMINATION OF URANIUM IN NATURAL WATERS 185

graphic analyses. Following the same procedure Thompson and 

Lakin, working in the dry atmosphere of the Western United States, 

found that no separation of the uranium occurred. Different drying 

conditions had to be established to compensate for the lower relative 

humidities, but the rather close control of the drying time set by them 

proved to be a handicap in the proposed field method.

The present writers prepared dilute nitric acid solutions of uranium 

collected from a natural water and dried 0.01, 0.02, and 0.05 ml 

aliquots for different periods of time at relative humidities varying 

from 9 to 81 percent. The results of these experiments are shown in 

table 1.

TABLE 1. Effect of relative humidity on drying of chromatographic papers

Relative humidity over 

saturated solutions 

(percent)

9

31... _-___.. __ .. ......

43 -. __ ... 

47 .... .... ...

52 

52 

81

Salt used 1

CaCb.anh _______ .

CaCk.eHaO _______

K2CO3.2H2O. __ .-----.

KSCN,.. ...............

NaH804 .HjO ....... .

Mg(NO»)j.6H»O._ .

(NH4) 2S04 .. ..

Temperature (°C)

24.5 

24.5 

24.5 

20 

20 

24.5 

20.25

Appearance after given drying times, in 

minutes (D, detectable band; I, iron 

movement; F, fair band; G, good band)

10 

G 

G 

G 

G 

G 

G 

F

15 

D,I

V

G 

G 

G

F

30 

D,I

V

G 

G 

G 

G

1,200 

D,I 

D,I 

D I 

D,I 

G 

G 

F

1 Lange, 1952.

A drying time of 10 minutes at relative humidities below about 50 

percent seems to be satisfactory, but longer times cause uncertain 

separations of the uranium from the iron with resulting poor band 

development. To avoid the highly problematical question of whether 

10 minutes is long enough for the atmosphere within the usual desiccator to reach equilibrium and to make the drying step more objective, 

the writers prefer to dry the sample aliquots for at least 30 minutes. 

The data show that sample aliquots can be dried for 30 minutes at 

relative humidities varying from about 40 to 80 percent.

Presumably the relative humidity becomes more critical with longer 

drying times. However, at a 52 percent humidity the sample aliquots 

can be kept for several weeks before proceeding with the chromatographic separation.

Saturated solutions of both sodium bisulfate and magnesium nitrate 

hexahydrate provide a 52 percent relative humidity at temperatures 

of 20° to 25°C. The latter desiccant was selected for the work reported in the rest of this paper because the vapor pressure is less 

sensitive to changes in temperature. In fact, satisfactory chromatograms have been prepared from paper containing 0.02 ml aliquots of 

sample solutions kept over the magnesium nitrate hexahydrate desiccant for as long as 3 months.
186 CONTRIBUTIONS TO GEOCHEMISTRY .

SOLVENT MIXTURES

Arden, Burstall, and Linstead (1949) used a solvent consisting of 

90 percent ethyl acetate and 10 percent concentrated nitric acid 

(volume per volume) to separate uranium chromatographically. In 

a procedure for determining uranium in soils, Hunt, N.ort4,> and Wells 

(1955) used the same solvent modified by the addition of 5 percent 

of water (volume per volume). Thompson and Lakin used a 2-phase 

solvent prepared by mixing 30 ml of ethyl acetate, 3.5 ml concentrated 

nitric acid, and 10 ml of water. Obviously the various workers in the 

field have modified the solvent to meet their particular need.

Using the definite drying conditions given in the previous section 

and 30 ml of ethyl acetate in the solvent, the present writers investigated the effect of different amounts of acid in the solvent on the 

chromatographic separation of 0.2 microgram of uranium on paper 

strips. The results are as follows:

I

Appearance after

development (t),

detectable band;

T, trailing behind

solvent front;

Percent nitric add F, fair band; 

volume-per volume G, good band)

6 D

10 F, T

12 F, T

14 G

17 G

19 F

21 G, T

23 F, T

25 F, T

Varying amounts of water were added to the solvent mixtures 

containing respectively 14 and 17 percent nitric acid (volume per 

volume). The characteristics of the bands obtained by making 

chromatographic separations with these solvents are given in table 2.

It is evident that a wide range hi the composition of solvent mixtures 

can be tolerated under normal conditions. However, if the ratio of 

the acid to the water is much greater than 2, the solvent becomes a 

2-phase system which may not provide enough nitrate to stabilize 

the uranyl ion and thereby cause it to move in the solvent front. 

All the separations described in the rest of this paper were made with 

& single phase solvent (see "solvent mixture" below).
FIELD DETERMINATION OF URANIUM IN NATURAL WATERS 187

TABLE 2. Effect of water in solvent at 14 o^d 17 percent add concentration on 

chromatographic separations

Water added (ml)

0____ ___ . ________ _ _____ _. _______ . __

t).5_ _ _

1.0 _

1.5__ .. .. __._

2.0 _ _ __...._. _ _._...........__._..__.__.

2.5 ....

3.0 ________ __ . ____ ._._.._....___...__ __

Appearance after development (D, 

detectable band; F, fair band; 

G, good band; T, trailing behind 

solvent front)

14 percent nitric 

acid

G, T 

G, T 

G 

G 

G 

F, T 

F

17 percent nitric 

acid

G, T 

G 

G 

F 

F 

D 

D, T

REAGENTS AND APPARATUS

Ammonium hydroxide, concentrated, reagent grade.

EDTA, Ethylenediaminetetraacetic acid, disodium salt. 5 percent aqueous.

Magnesium nitrate hexahydrate, reagent grade. A saturated aqueous solution 

is used as the desiccant for drying sample and standard aliquots.

Nitric acid, Sp. G. 1.42, reagent grade.

Nitric acid-aluminum nitrate reagent. Dissolve 80 grams of aluminum nitrate 

enneahydrate in mixture of 25 ml concentrated nitric acid and 75 ml water.

Potassium ferrocyanide, 5 percent aqueous.

Phosphate reagent. Sodium phosphate, dibasic, saturated aqueous solution of 

the dodecahydrate.

Solvent mixture. To a clean dry 600 ml beaker, add in this order: 30 ml ethyl 

acetate, reagent grade; 6 ml concentrated nitric acid; and 0.5 ml water. Swirl 

to obtain clear solution and cover. The mixture can be used immediately, 

and it is good for 4 to 5 chromatograms or 4 hours, depending on whichever 

involves the shorter time.

Standard uranium solution, 0.1 percent. Dissolve 0.211 gram of uranyl nitrate 

hexahydrate in 100 ml of nitric acid-aluminum nitrate reagent. Prepare 

dilute standard solutions by adding 0.1, 0.2, 0.4, 0.8, 1.5, 3, and 6 ml of 0.1 

percent standard to a series of 10 ml volumetric flasks 0.1 ml to first flask, 

0.2 ml to second flash, etc., and making volume up to mark with nitric acidaluminum nitrate reagent.

Atomizer.

Beakers, 600 ml. Two or more are used for greatest efficiency.

Bottles, dropping, 30 and 60 ml capacity.

Crucibles, porcelain no. 0. High form.

Desiccator, 150 mm in diameter. For efficient operation two or more are required: 

one for standards and other for samples. i

Filter apparatus, shown in figure 18. Before using, prepare slurry of one Whatman 

ashless tablet and collectpulp on filter paper circle placed over small holes in D, 

after connecting B and D.
188 CONTRIBUTIONS TO GEOCHEMISTRY

Paper, Whatman no. 1-2J^ cm circles for retention of item C in figure 18.

Paper, Whatman CRL-1 Chromatographic, ten chromatograms can be made or*

each sheet.

Pipettes, micro, capacity 0.05, 0.02, and 0.01 ml. 

Pipette, measuring, calibrated in tenths of a ml.

pH test paper, long range from pH 1-6 and short range from pH 5.8-6.2. 

Rods, small glass stirring. 

Stove, gasoline portable, with steel plate to serve as hot plate.

PROCEDURE

To a 500 ml sample of natural water add 2 ml concentrated nitricacid. Add concentrated ammonium hydroxide drop by drop until, 

the pH is 2.5. Add phosphate reagent until pH is 5.9 to 6.1. If a. 

precipitate forms on the addition of phosphate, add EDTA drop bydrop to the stirred sample solution until the precipitate redissolves,, 

and then alternately titrate the sample solution drop by drop, first, 

with phosphate reagent and then with EDTA until pH is 5.9 to 6.1.. 

Filter water through paper pulp in the filter apparatus shown in 

figure 18. After water filters through paper pulp, separate item B' 

from A and cover with stopper E.

To determine the uranium collected, transfer the paper pulp to a, 

porcelain crucible. Add 4 to 5 drops of concentrated nitric acid and', 

dry on hot plate. Heat over open flame until only a white ash 

remains. Cool. Add 0.5 ml of concentrated nitric acid to the ash, 

heat gently to dryness, and ignite to expel nitric oxide fumes. Cool. 

Repeat the addition of concentrated nitric acid. Police the sides of" 

the crucible with a small glass stirring rod and evaporate the liquid 

in the crucible to dryness. Dissolve all residue in the cool crucible 

in 0.2 ml of nitric acid-aluminum nitrate reagent and warm gently 

for 20 seconds. Avoid boiling.

Transfer a 0.02 ml aliquot of the warm sample solution to a stripof chfomatographic paper. Place strip in the desiccator and allow it 

to remain for at least 30 minutes. Remove paper from desiccator and' 

place lower end of the paper in the solvent mixture. Allow solvent to 

rise through the dried sample aliquot to within 1 inch of the top of 

the paper. Remove strip from solvent, dryr and spray both sides of 

the paper with potassium ferrocyanide reageatt.

Preparation of standard bands Place 0.01 ml aliquots from each of 

the 10 ml volumetric flasks containing dilute standard uranium 

solutions on strips of chromatographic paper and allow to dry one-hall 

hour in desiccator. Place paper strips in solvent and continue as 

with samples. These standard bands contain, respectively,, Q.I,.0.2, 

0.4, 0.8, 1.5, 3.0, and 6.0 micrograms of uranium...
FIELD DETERMINATION OF URANIUM IN NATURAL WATERS 189

FIGURE 18. Filter apparatus.

Estimation Compare chromatograms of samples with those of 

standard solutions to determine uranium content of aliquot. Multiply 

the uranium content of the corresponding standard chromatogram 

by 20 to convert the results into parts per billion in original sample.

RESULTS

The proposed procedure was tested by adding different amounts of 

uranium to 500 ml portions of 3 different natural-water samples of 

known uranium content and taking the portions through the entire 

procedure. The results are shown in table 3.
190 CONTRIBUTIONS TO GEOCHEMISTRY 

TABLE 3. Recovery of added uranium

Laboratory no.

CR-2-566. ___________________

CR-2-568- ___________________

CR-2-5618- __.________..___._

Uranium 

present 

(micrograms 

in 500 ml)

3

10

Uranium 

added to 600 

ml micrograms

2

5

10

10

2

4

8

16

32

40

50

Uranium 

found micrograms

4

8

10

20

2

4

7

12

28

40

50

Uranium 

recovered 

micrograms

1

5-

7

1O

1

a

6

11

27

39-

49

The recoveries of added uranium shown in column 5 are good, and 

they provide evidence that little uranium is lost during the various 

steps.

For additional evidence of the validity of the proposed method, 

mixtures were prepared from 2 different natural-water samples whoseuranium content had been established by a laboratory method. The* 

results obtained by analyzing these mixtures are given in table 4.

TABLE 4. Determination of uranium in binary mixtures

Laboratory no.

CR-2-5612___ ___________ _

CR-2-5613 _____

CR-2-5614___________ _ _>_

CR-2-5615______.____ ___ _

CR-2-5616 ___ ________ _ _

CR-2-5617______ ___ ______

CR-2-5618. ___ _.__ ___ ._

Composition 

of mixture 

Component 1

Component 2

q/7

1/1

2/3

1/1

1/19

4/1

1/1

Uranium 

content 1 Com-

(PPb)

30

25

30

30

320

25

240

Uranium 

content Com-

(ppb)

2

<2

2

2

<2<-"9

<2

Uranium 

content 

of

(ppb)

10.4

12. 5

13. 2

16

16

20

120

Uranium 

found 

(ppb)

8-

10>

10

16

16

16

12O

| i Analyses made in laboratory of Quality of Water Branch, U. S. Geological Survey, Denver, Colo.

The agreement between the calculated uranium content and that 

found by the proposed method shown, respectively, in columns 5 and 6 

is quite satisfactory.

The proposed method was tested for repeatability by making 5 

separate uranium determinations at different times on 5 different 

natural-water samples. The determinations were made from large 

bulk samples acidified with nitric acid to permit storage without lossin uranium content. The concentration of uranium-ranged from 5 to> 

300 ppb, and the results of these determinations are shown in table 5..
FIELD DETERMINATION OF URANIUM IN NATURAL WATERS 191 

TABLE 5. Repeatability of uranium determinations

Laboratory no.

CR-2-566__- ..___. _.

CR-2-56 10. _________

CR-2-5611.__ __ ___

CR-2-5612- _ ___-_-._

CR-2-568_-_.___.___

Uranium, ppb

1

6 

16 

30 

160 

300

2

5 

16 

30 

120 

320

3

4 

10 

25 

160 

300

4

6 

12 

30 

160 

300

5

5 

W 

30 

140 

320

Mean

5.2 

140 

29.0 

148.0 

308.0

The repeatability of the proposed method is good over the concentration range covered.

The accuracy of the field procedure was tested by comparing the 

results obtained on 8 water samples with those obtained by a laboratory procedure. The comparison is shown in table 6.

TABLE 6. Determination of uranium in water

Laboratory no.

Uranium, ppb

CR-2-562__ _______________________________

CR-2-563- ________________________________

CR-2-564_ _____________________________ _

CR-2-565_ _____________________________ _

CR-2-566__.__ _ ____________________ _____

CR-2-567. ________________________________

CR-2-568__--______ _ _____--_.__ _ __. _

CR-2-569- ________________________________

Laboratory '

0. 5

1. 5

2. 6

2.8

5.9

15

27

60,85

Field

<2

<^?

2

2

6

10

25

60,75

1 Analyses made in laboratory of Quality of Water Branch, U. S. Geological Survey, Denver, Colo.

The laboratory results were obtained by another laboratory of the 

U. S. Geological Survey using a procedure in which the uranium is 

concentrated by evaporation of the water sample and subsequently 

determined fluorimetrically. The favorable comparison shown in 

table 7 is good evidence that the proposed field method is moderately 

accurate.

The proposed method is reasonably precise and relatively fast. It 

permits the easy determination of uranium in natural waters under 

field conditions and thus eliminates the collection and costly transportation of bulky water samples from field to laboratory. With the 

proposed method, research on principles of hydrogeochemical prospecting is facilitated, but, perhaps of greater importance, hydrogeochemical prospecting for uranium now becomes practicable for the 

individual prospector.
192 CONTRIBUTIONS TO GEOCHEMISTRY

LITERATURE CITED

Arden, T. V., Burstall, F. H., and Linstead, R. P., 1949, A new method for the

detection and determination of uranium: Chem. Soc. London Jour. Suppl.

issue 2, p. S 311-313. 

Grimaldi, F. S., May, Irving, Fletcher, M. H., and Titcomb, Jane, 1954, Collected

papers on methods of analysis for uranium and thorium: U. S. Geological

Survey Bull. 1006, p. 126. 

Hecht, F., Korkish, J., Patzak, R., and Thiard, A., 1956, Zur Begiiittmung

kleinster Uranmengen in "Gestemen and naturlichen Wassern: Mikrochim.

Acta, nos. 7-8, p. 1287. 

Hernegger, F., and Karlik, B., 1934, Die quantitative Bestimmung sehr kleiner

Uranmengen und der Urangehalt des Meerwassers: Akad. Wiss. Wien,

Math, naturwiss. Kl., Sitzungsber., Abt. Ha, 144 Band, p. 217. 

Hunt, E. C., North, A. A., and Wells, R. A., 1955, Application of paper chromatographic methods of analysis to geochemical prospecting: Analyst, v. 80,

p. 172-194.

Lange, N. A., 1952, Handbook of chemistry: Sandusky, Ohio, Handbook Publishers, Inc., 8th ed., p. 1454-1455. 

Rodden, S. J., 1950, Analytical chemistry of the Manhatten Project: New

York, McGraw-Hill Book Co., p. 37. 

Thompson, Charles E., and Lakin, H. W., 1957, A field chromatographic method

for the determination of trace quantities of uranium in soils and rocks:

U. S. Geological Survey Bull. 1036- [in preparation]. 

Tschernichow, J. A., and Guldina, E., 1934, Colorimetrische Bestimmung von

Uran in uranarmen Erzen: Zeitschr. anal. Chemie, v. 96, p. 260. 

Urry, W. D., 1941, The radioactive determination of small amounts of uranium:

Am. Jour. Sci., v. 239, p. 191-203.

O