cirouyanthraquinone compounds listed in Table I-e.g., tribromoanthrarufin and dicyanoquinizarin, if subjected to further study, could prove to be equal to or better than these three reagents. (C'arniinic acid, while widely used, suffcrs from the coinpl&ty of the color development reaction with boron and 1 ariability of reagent purity. Of all of the reagents listed, present information indicates that the hydroxymthraquinones and anthraquinonylamines are the least subject to interfercnce from other elements. The investigations of Pasztor et. al. (21-23) and Skaar (29) indicate that methylene t h e and the other thionine derivation< are also relatively specific for boron. The choice of any particular reagent foi the determination of boron is gor~ r n e dby a number of factor., including +en>itivity, case of uze, interferences from other element>, and knowledge of optimum conditions For color development. I n the range oi 0.1 to 1 pg, of boron/ml., the hydrclxvanthraquinones :ire the best choice of reagents in terms of thc above factors. -1mong the three best reagents in thi.. series, diaminochrysazin, tetrabroniochrysazin, and yuinalizarin, practic:il differences in w x i t i v i t y are negligible and quin:ilizarin, because of extensive knowledge of optimum condition. of color development, is usually the most useful of the three. I n the range of 0.05 to 0.5 pg.
(17) Keummel, I). I?,, Melion, AI. G., Ibid., p. 378. (18) Luke, C. I,., Faschen, S. S.. Zbzd.,
of boron/ml., significant increases in sensitivity are gained with the anthraquinonylamines, and while theee reagents are still relatively free from interference, they are not so convenient to use as the hydrosyanthraquinones. Where senhiti\ ity is the limiting consideration (0.01 to 0.1 pg. of boron/ml.) the use of curcumin or methylene blue is indicated, n i t h the latter being the most uvfu1 reagent. LITERATURE CITED
(1) ANAL.CHEM.34, 1852 (1962). ( 2 ) Baron, H.. 2. Anal. Chem. 143, 339 (19.i4)
\----,-
(3) Brewster, L). A,, ASAL. CHEM.23, 1809 (1951). (4) Calkins, IZ. C., Stenger, V. A , , Zbid., 28, 399 (1956). ( 5 ) Callicoat, D. L., Wolzon, J. D., Zbid., 31,1434 (1959). ( 6 ) Campbell, R. H., hlellon, PI. G.>Ibid., 32,50 (1960). ( 7 ) Cogbill, E. C., Poe, J. H., Ibid., 29, 1251 (1957). (8) Cogbill, E. C., Yoe, J. H., Anal. Chim. dcta 12, 455 (1955). ( 9 ) Danielson, L., Talanta 3, 138 (1959). (:LO) Ducret, L., Anal. Chim. Acta 17, 213 (1957). ( : t 1 ) Eberle, A. R., Lerner, A f . K., ASAL. CHEST. 32, 147 (1960). 11.2) Ellis. G. H.. Zook. E. G..' Baudisch. 0.. O., Zbid:. Ibid:, 21. 21, 1345 (1649). (1949). ~, (1.3) 'Grob,' Grob, R.'L., R. I.., Yoe, J. H., Anal. Chim. Acta 14, 253 (1956). (1.4) Hatcher, J. T., \vileos, L. I-.>ANAL. CHEM.22, 567 (1950). ( I 5) Higgs, D. G., Analyst 85, 897 (1960). (16) Jones, A . H., ASAI.. CHEY.29, 1101 (1957). ~\
~
30, 1406 (1958). (19) MacDougall, D., Biggs, D. .I., Zbzd 24, 566 (1952). 120) Olson, L. C., DeTurk, E. E., Sozl ' dci. 50, 257 ( 1 9 ~ 0 ) . (21) Pasztor, I,., Bode, J. D., ASAL. CHEM.32, 1530 (1960). (22) Pasztor, L., Bode, J. I]., A d . ('hint. Acta 24, 467 (1961). (23) Pasztor, L., Bode, J. D., Fernmdo, &., ANAL. CHEV.32, 277 (1960). (24) Powell, W. A., U . S . At. Energy Comm. Rept. CCC1024-TR-226. (25) Powell, IT. A., C . S . At. Energy Cornm. Rept. CCC1024-TR-229. (26) Puphal, K. W.,hlerrill, J. A , , Booman, G. L., Rein, J. E., ANAL.CHEM. 30, 1612 (1958). 127) Revnolds, C. A , , Ibid., 31, 1102 (1959j. (28) Ross, M'. J., Meyer, A. S.. IF-hite, J. C., U S. At. Energy Comin. Rept. ORNL-2 135. (29) Skaar, 0. B., Anal. Chinz. Actn 28, 200 (1962). (30) Smith, W.C., Goudie, A. J., Sivertson, J. X., AKAL.CHEM.27,295 (1955). (31) Srivastava, R. D., VanBuren, P. R , Gesser, H., Ibid., 34, 209 (1962). (32) Reinberg, S., Proctor, K. L.. Milner, O., Ibzd., 17, 419 (1945). (33) Yoe. J. H., Grob, R . L., Z b z d , 26, 1465 (1954). G. R . GOWARD' V. R. WIEDEKKEHR
Bettis Atomic Power Laboratory Westinghouse Electric Corp. Pittsburgh 30, Pa. Present address, Pratt & T I liitney Aircraft, North Haven, Conn.
Spectrophotometric Determimation of Niobium in Ura nium-Fission Element Alloys SIR: I n studies connected with the processing of fuels for the Second Experimental Breeder Reactor (EBR11), it has been necesm-y to determine as low as O . O l % of niB3bium in uranium wllo~-scontaining molybdenum, ruthenium. palladium, rhodium. and zirconium. A proceduri. for the spectrophotometric det'erniination of niobium in rocks reported by Grimaldi ( 2 ) appeared to be adaptabl: t o such samples. I n Grimaldi's proccdure, niobium thiocyanate complex i., formed in a mixture of tartaric, hydrochloric, and sulfuric acids, arid then extracted into ethyl acetate. Iron is stripped from the organic with a stanr: ous chloride-aminonium thiocyanate-hydrochloric acid solution. hfter dilution to volume TTith (,thy1 acetate, the aworbance of the niobium thiocyanate is measured a t 3% mp in 5-em. cells. Of the elements prwcnt in uraniumfission element alloys (fssium) uranium, molybdenum, and .ruthenium interfere in a thiocyanate procedure. ~
Ruthenium is removed by fuming with perchloric acid while uranium does not extract' under the conditions used. hIolybdenum is separated by precipitating niobium with ammonium hydroxide uiiiig uranium as a carrier. This technique !vas originally used by Evans, Hiobar, and Patt'erson (1) in separating zirconium from similar alloy solutions. stripping solution was used by Grimaldi to prevent the interference of rrilligram amounts of iron and titanium. This solut'ion decomposed quickly causing erratic results. Since the iron content of the fissium alloys is very low and no titanium is present! the use of this solution was eliminated. EXPERIMENTAL
Reagents. Extraction solution: 65 ml. of 6 S hydrochloric acid, 4 ml. of l%Y sulfuric acid, 10 ml. of 25y0 tartaric acid, diluted to 100 ml. All other reagents are prepared as reported by Grimaldi (2) .
Recommended Procedure. Pipet a sample containing 1 to 15 pg. of niobium into a 50-ml. beaker. Add 5 ml. of concentrated sulfuric acid and 3 ml. of concentrated perchloric acid and fume to incipient dryness. Cool, rinse the sides of the beaker with water, add 2 nil. of concentrated sulfuric acid and 1 ml. of concentrated perchloric acid, and again fume to incipient dryness. Cool and transfer n i t h water to a centrifuge cone that contains 10 nil. of concentrated ammonium hydroxide. Centrifuge and discard the supernate. Dissolve the precipitate in 2 nil. of concentrated hydrochloric acid and dilute to 10 nil. with mater. Transfer with water to another centrifuge cone that contains 10 ml. of concentrated amnionium hydroxide. Centrifuge and discard the supernate. Dissolve the precipitate in 10 ml. of extraction solution and transfer to a 60-ml. separatory funnel. Wash the centrifuge cone u ith two 5-ml. portions of the extraction solution. Then carry out the following part of the procedure as quickly as possibleadd 5 ml. of 25y0 ammonium thiocyanate and 0.5 nil. of 407, stannous VOL. 3 5 , NO. 10, SEPTEMBER 1 9 6 3
1545
Table I.
..
Determination of Niobium in Synthetic Solutions
O . i , 10.4 5.0 4.s, 3 3 ... . . . .) .j 2.4, 2.2 1.23 .. ... ... ... 10.0 !) (i. 10.2 .. , . . 1 i3.j ... . . . ... 10 0 10.(i ... ,.. , . 0 . 18 ... . . . 10.0 10.3 ... ... ... 0.10 ... 10.0 10.2 .. , . . ... ... ... 0 25 10.0 9 . .i 50 1.25 1.35 0.13 0.10 11.25 5 0 .i 3 20 0.50 0.a4 0.05 0.04 0.10 2 3 2 :z 10 mg. of I- used ns carrier for nii~hiu~ii except in tlrose mses where sep:irntion was iiiade f r o m fissiuni. 1)aily variation in hlanlc corresponded t o 4 ~ 0 . 3p g . of niohiuiir.
.. ..
. , .
. .
...
.. ..
.. ... ..
... .. ..
10 0
I . .
,
coiiiuni, and niobium arid was iati3factory. Typical data on solutions coiitaiiiing known amounts of nioliiuni art' shown in Table I. t*nirradiated urnnium-3% fission element alloys having a noniiiial conipoaition of 0.01 7, iiioliuni were analyzed by the thiocyaiiatr method aiid wwe fouiid to contain 0.0117, iiiobiuni. LITERATURE CITED
,
,
,
+
taliloride to the separatorj- funnel and mix well. .ldd 20 nil. of ethyl acetate m d extract for 1 minute. I h c a r d the aqueous and scrub t'he organic phase for 1 minute with a mixture of 10 nil. of the extraction solution, 2 nil. of 25% wiiiionium thiocyanate, and 0.25 nil. l)f 40% stannous chloritic. Discard the aqueous aiid repeat the acruh. I h i i s f e r the organic to a 2.5-inl. volu-
metric flask. Dilute to volunie nitli ethyl acetate and read in 5-cni. cells
at 385
nip.
(1) Evaiis, H. B., Hrohar, .I.S.,I'utterson, J. H., .Is.ir..CHEM.32, ML (I!W). ( 2 ) Ciriiiialdi, F. S., Ihitl., 32, ll!) (l!?SO).
,J, ,J. 1IcCoivs 1). 1:. KI-I)ER.A hrpoiiiie Sationnl Lahorntory
Idalio Ilivision P. 0 . Box 232s 1d:tho Falls, Idaho
RESULTS
Thc procedurr has I)wn tested on *riythetic d u t i o n s containing kllon.11 m o u n t s of uranium, niolylidenruii, rutheniuni, palladiuni. rhodiuni, zir-
Opernred t h e '-nivereity O f CLlicagr' under Contract S o . \$.-3 t-lO!j-eng-%. i v l ) r k I,erfl,rrrledunder ;l,,sl)ic.es the [.. S. .itonric Energy C~oliriilission,
1,2,3-Tris(2-cyanoethoxy)propane as a Stationary Phase in the Gas Chromatographic Ana lysis of Aromatic Hydrocarbons Sra. The suli+uice, 1,2,3-tris(2-cyLtiioetlioXy)propane, has l m n proposed :t'i a st,ationary phase in gal; chromatography because of its high sPlectivity ( 2 , 3 ) . AIcSair and 1 k I r r i t ~ sused a c d i i n i n containing 30:L of tlir iuhstratr anti reported retention voluniw a t 55 ', IOO", and 153" C . for a f e n represrntativr members of a nunihrr of seriea iiicluding the olefins, aromatics, naphtheiiea, alcohols, esteri, ethers. arid :tlkyl halides. 'I'liese investigators did not report tlir ilrtailed application of lJ2J-tris(2-cyLtnoet1ioxv)propanp in an individual w i r s . Further investigation ha.; s h o ~ v n that this substrate is excellent for tlw wl)aration of six- to 10-carbon aromatic !iydrocarhons wit'li saturated and un-;attirated side chains. Furtliermorr, f the ,substrate perinits with tlic~flaine ionization detector of aroniatic liyrlrocarlioiis in i ~ m p l r scoiiihustion and pliotoclicinic d l y irradiated mixturw a t lt~velsas low x i 0.01 t o 0.1 p,p.iii. .I C a r h w a s 1540 d w t r a t e wa- uscd ~mviouslyfor such t r a w analyses ( 1 ) . A soniediat morr +elrctive analysis is ohtailid using 1,2,3-t-is(2-cyanoetlioxy)i~roi)an(~with lws tailing of band rqiial Iiase line stalii EXPERIMENTAL
Sweral commercial chroiiiatographic instruments and detectors were used.
1546
ANALYTICAL CHEMISTRY
Tlie flow >vstwis nere mudifird for a c c x a t e control of the hydrogen and air flow. 'l'lie helium used as thc rarriw gas, the prepurified hydrogen, and air \\ere p a ~ through d a molecular -le\ c to remove i t ater and other impurities. The 1,2,3-tri~(2-cyanoet hoLy)propane was obtained from -\pplied Science Laboratoriez, Inc,, State College. Pa. Powvdrred. washrd C-22 firebrirb
~ c r e ( w dto 50- to 6O-niesh \vas uied 3s the solid siiliport. Tlic colunins w r v preparrd liy wt4ghing apl)rol)riate quailtitie3 of tlic' liquid, dissol\-ing it in acetoiic., arid adding enough of the solid support t o give columns n-ith 5 or l5Y0 of substratcl. The solvent \vas evaporated on a rotary evaporator aiid the material dried for 24 hours in an ovrn a t 110' C. The stainless stwl colunins
COLUMN: 59. 12.3-TRIS 2 CYANOETHOXYI PROPANE ON 5 0 / & 0 MESH 22:i FIREBRICK 111 X I/@'O D 75cs OF H e / M I N , T E M R 6O.C
w
-
-, I
DETECTOR: HYOROGEN F L I M E 3 0 c c OF H L / M I N . 3 5 0 c c OF 30% OXYGEN I N ARGON / MIN
TIME MINUTES
Figure 1. Chromatogram of a 27-component mixture of aromatic and aliphatic hydrocarbons
