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Annotated Bibliography of the 

Analytical Chemistry of 

Niobium and Tantalum 

January 1935-June 1953 

~ GEOLOGICAL SURVEY BULLETIN 1029-A z 

~ 

This report concerns work done partly on behalf 

of the U. S. Atomic Energy Commission 

and is published with the permission of 

the Commission 
· Annotated Bibliography of the 

Analytical Chemistry of 

Niobium and Tantalum 

January 1935-June 1953 

By FRANK CUITITT A 

SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

GEOLOGICAL SURVEY BULLETIN 1029-A 

This report concerns work done partly on behalf 

of the U. S. Atomic Energy Commission 

and is published with the perrnission of 

the Commission 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1957 
• . • ' ~ 1 • : • ' '. • : : ! f . \ I I ' . . . • ~ • 

UNITED STATES·DEPARTMENTOF THE INTERIOR 

,; 

GEOLOGICAL SURVEY l 

Tho~~s 's~' N~i~~·~ Dir~i~,:· . ·• •. l. J'. 

• 1 • ; .. :· •• • .... 

.• i.'. 

\':-\ 

For ~sa1e by the- Suihlrintendent orno·cumen.t.s;-·u. s.-Government P'ibitfn£ Office---

Washington 25 ·D.· C.- Price: 25 cents ·(paper cover)·. · • . , ·. i .: ! •• ' 
CONTENTS 

Abstract ...................................................... . 

Introduction ................................................... . 

Atomic Energy Commission reports .............................. . 

Atomic Energy Commission depository libraries .................. . 

Serials ........................................................ . 

Bibliography .................................................. . 

Author index .................................................. . 

Subject index 

III 

Page 

1 

1 

2 

2 

5 

11 

61 

65 
SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

ANNOTATED BIBLIOGRAPHY OF THE ANALYTICAL 

. CHEMISTRY OF NIOBIUM AND. TANTALUM 

JANUARY 1935-JUNE 1953 

By FRANK CUTTITTA 

AJ3STR.ACT 

This annotated bibliography includes· reports of work published in 

the period January 1935 to June 1953 and has been compiled mainly 

from Chemical Abstracts and from Nuclear Science Abstracts. It refers the reader. to the original publications and to abstracts and discussions (summaries} of them. Author· and subject indexes are supplied, and also. lists of abbreviations used for the serials to which reference is made, and of Atomic Energy Commission code designations and 

depository libraries where reports so designated can be examined or 

obtained. 

IN~.rnODUCTION 

In connection with studies on the analytical chemistry of niobium and tantalum,. undertaken by the U. S. Geological Survey 

on behalf of the Division of Raw Materials of the U. S. Atomic 

Energy Commission; ·a search of the literature has been made on 

this subject. Most of the references are accompanied by annotations or abstracts, many of which were copied, in part or in whole, 

from such standard sources as Chemical Abstracts or Nuclear 

Science Abstracts; they cover approximately the period January 

1935 through June 53. Some annotations were obtained fron1 other 

secondary sources or from the papers themselves. 

The bibliography is arranged alphabetically by author. Titles 

of reports are in English, as given in the secondary sources. 

Lists of code designations of unclassified Atomic Energy Commission reports and of cooperating libraries at which the reports 

are available for examination follow the general introduction. In 

t.urn they are follo,:ved by a list - in both abbreviated and full 

1 
2 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

form - of the serials to which reference is made in the bibliography. Names of serials are in the language of the country, abbreviated according to rules followed in the Geological Survey. 

Author and subject indexes are provided for easy use of the 

bibliography. Each index is preceded by a brief introduction which 

describes its arrangement. The subject index is most important to 

the bibliography, and great care has been taken to include index 

reference to even small amounts of data presented in the annotations and abstra·cts. 

A revision of this bibliography may be prepared in the future. 

The compiler would appreciate receiving .information on errors of 

omission or commission which. have occur~ed in this compilation. 

ATOMIC ENERGY COMMISSION REPORTS 

[Key to code designations of Atomic Energy Commission reports. Most nonclassified 

research and development reports of the Atomic Energy Commission and its contractors are 

or will be supplied to its depository libraries listed on a following page. Inquiries should be 

addressed to the libraries] 

Gods 

AECD 

AECU 

ANL 

CRL/AE 

K 

MDDC 

NEPA 

NP 

ORNL 

UCRL 

Installation 

Atomic Energy Commission, Manhattan Engineer District. Declassified documents AECD-1780 on, released after February 29, 

1948. See also MDDC~ 

Atomic Energy Commission. Unclassified Reports. 

Atomic Energy Commission, Argonne National Laboratory. 

Department of Scientific and Industrial Research, Chemical Research Laboratory, Teddington, England. 

Union Carbide Nuclear Co., Oak Ridge Gaseous Diffusion Plant. 

Atomic Energy Commission, Manhattan Engineer District. Declassified documents MDDC 1 to 1779 released prior to March 1, 

1948. See also AECD. 

Atomic Energy Commission, Nuclear Energy for Propulsion of 

Aircraft. 

"Non-Project." University research and development reports received from non-AEC contractors. 

Union Carbide Nuclear Co., Oak Ridge National Laboratory. 

University of California, Radiation Laboratory. 

ATOMIC ENERGY COMMISSION DEPOSITORY 

JJIBRARIES I 

[List of the depository libraries to which most nonclassified research and development 

reports of the Atomic Energy Commission and its contractors are or will be supplied. Reports may be examined at or borrowed from these libraries, and microfilm or photostat copies 

may be purchased from them. Inquiries should be addressed to the libraries] 

Sta.u City a.nd Lib-raf'11 

California ............. Berkeley. University of California General Library. 

Los Angeles. University of California Library. 

Colorado . . . . . . . . . . . . . . Denver. Denver Public Library. 

Cmi:riecticut . . . . . . . . . . . New Haven. Yale University Library. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 3 

Sta.ttJ City a.nd Libra.ru 

District of Columbia Washington. Library of Congress. 

Georgia . . . . . . . . . . . . . . . Atlanta. Georgia Institute of Technology Library. 

Illinois ............... Chicago. John Crerar Library. 

Chicago. University of Chicago Library. 

Urbana. University of Illinois Library. 

Indiana ............... Lafayette. Purdue University Library. 

Iowa . . . . . . . . . . . . . . . . . . Ames. Iowa State College Library. 

Kentucky ............. Lexington. University of Kentucky Library. 

Louisiana ............. Baton Rouge. Louisiana State University Library. 

Massachusetts ......... Cambridge. Harvard University Library. 

Cambridge. Massachusetts Institute of Technology 

Library. 

Michigan . . . . . . . . . . . . . Ann Arbor .. University of Michigan Library. 

Detroit. Detroit Public Library. 

Minnesota ............. Minneapolis. University of Minnesota Library. 

Missouri . . . . . . . . . . . . . . Kansas City. Linda Hall Library. 

St. Louis. Washington University Library. 

New Jersey ........... Princeton. Princeton University Library. 

New Mexico ........... Albuquerque. University of New Mexico. 

New York ............ Buffalo. Lockwood Memorial Library. 

Ithaca. Cornell University Library. 

New York. Columbia University Library. 

New York. New York Public Library. 

Troy~ Rensselaer Polytechnic Institute. 

North Carolina ........ Durham. Duke University Library. 

Raleigh. North Carolina State College Library. 

Ohio .................. Cincinnati. University of Cincinnati Library. 

Cleveland. Cleveland Public Library. 

Columbus. Ohio State University Library. 

Oklahoma ............. Stillwater. Oklahoma Agricultural and Mechanical 

College Library. 

Oregon . . . . . . . . . . . . . . . Corvallis. Oregon State College Library. 

Pennsylvania .......... Philadelphia. University of Pennsylvania Library. 

Pittsburgh, Carnegie Library of Pittsburgh. 

Tennessee . . . . . . . . . . . . . Knoxville. ·University of Tennessee Library 

Nashville. Joint University Libraries. 

Texas ................ Austin. University of Texas Library. 

Utah . . . . . . . . . . . . . . . . . Salt Lake City. University of Utah Library. 

Washington ........... Seattle. University of Washington Library. 

Wisconsin . . . . . . . . . . . . . Madison. University of Wisconsin Library. 

6 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

British Chern. Abs. . . . . . . . . . . . . . . . British Chemical and Physiological Abstracts. London. 

Canadian Min. Jour .............. Canadian Mining Journal. Quebec, Canada. 

Chern. Abs. . . . . . . . . . . . . . . . . . . . . . . Chemical Abstracts. Washington. 

Chern. Eng. Min. Rev .... : . ....... Chemical Engineering and Mining Review. Melbourne. 

Chern. Fabrik . . . . . . . . . . . . . . . . . . . . Chemische Fabrik. Berlin. 

Chern. listy . . . . . . . . . . . . . . . . . . . . . . Chemicke listy pro vedti. a prumysl. 

·' . Prague. 

Chern. Metall. Min. Soc. South Journal of the Chemical, Metallurgical, 

Africa Jour. . . . . . . . . . . . . . . . . . . . and Mining Society of South Africa . 

. Johannesburg, Union of South Africa. 

Chern. News . . . . . . . . . . . . . . . . . . . . . Chemical News. 

·.Chern. Soc. Japan Jour ........... Journal of the Chemical Society of 

Japan . 

. Chern. , Soc. . Japan Jour., Pure Journal of the Chemical Society of 

Chemistry Sec. Japan, Pure Chemistry Section. 

Tokyo. 

Chern. Soc. [London] Jour. . . . . . . . . Journal of the Chemical Society. London. 

Chemist Analyst .................. The Chemist Analyst. Phillipsburg, N.J. 

Chimie anal. .................... • Chimie analytique. Paris. 

Chinese Chern. Soc. Jour .......... Journal of the Chinese Chemical Society. Peiping, China. 

Coli. Czechoslovak Chern. Commun. . Collection of Czechoslovak Chemical 

Communications. Prague. 

Comm. geol. Finlande Bull. . . . . . . . Bulletin de la Commission geologique 

de Finlande. Helsinki, Finland. 

Electrochem. Soc. Japan Jour. . . . . . Journal of the Electrochemical Society 

of Japan. Tokyo. 

Foundry Trade Jour .............. Foundry Trade Journal. London, England. 

Gos. inst. priklad. · khimii Sbornik Gosudarstvennyy institut prikladnoy 

statey khimii, Sbornik statey. Moscow. 

Helvetica Chim. Acta. . . . . . . . . . . . . Helvetica Chimica Acta. Basel, Switzel'-

land. 

Indian Acad. Sci. Proc. 

Sec. A; Sec. B. 

Indian Chern. Soc. Jour. 

Indian Inst. Sci. Jour. . .......... . 

Inf. qu.imica anal. . .............. . 

Proceedings of the Indian Academy of 

· Sciences. Bangalore, India. 

Section A., Section B. 

Journal of the Indian Chemical Society. 

Calcutta, India. 

Journal of the Indian Institute of Science. Bangalore, India. 

Informacion de qu.imica analitica. Madrid. 

Indus. Chemist ................... Industrial Chemist and Chemical Manufacturer. London. 

Indus. Eng. Chemistry, Anal. ed ... Industrial and Engineering Chemistry, 

Analytical edition. 

Ingenieur chimiste ................ L' Ingenieur chimiste, Bruxelles. 
NIOBIUM AND TANTALUM, JANUARY 1935~JUNE, 1953 7 

Inst. Mining and Metallurgy Bull. . 

Iron Age ....................... . 

Iron and Steel [London] ......... . 

Jour. Applied Physics ........... . 

Jour .. chimie phys. . ............. . 

Jour. physique et radium ....... -.. 

Kaiser-Wilhelm-Inst. Eisenforsch. 

Dusseldorf Mitt. 

Khim. referat. zhur. 

Leningrad. krasnoznamenn. khim.-

tekhnol. inst. Trudy 

Metall u. Erz ................... . 

Metallurgia ................•..... 

Mikrochemie .................... . 

Mikrochemie ver. Mikrochim. Acta .. 

Mikrochimica Acta .............. . 

Mineralog. Abs. ................. . 

Mineral. syr'ye ................. . 

Mining and Metallurgy .......... . 

Bulletin of the Institution of Mining 

and Metallurgy. London. 

The Iron Age. New York, N. Y. 

Iron and Steel. London. 

Journal of Applied Physics. 

Journal de chimie physique et de physico-chimie biologique. Paris. 

Le Journal de physique et Le Radium. 

Paris. 

Mitteilungen a us dem Kaiser-Wilh«(lmInstitut fur Eisenforschung zu Dusseldorf. 

Khimicheskiy referativnyy zhurnal. 

Moscow. 

Trudy Leningradskogo krasnoznamennago khimiko-tekhnologicheskogo instituta. 

Metall und Erz, Zeitschrift fur Erzbergbau, Metallhuttenwesen und 

Metallkunde. Stuttgart. 

Metallurgia. Manchester, England. 

Mikrochemie. lnternationale Zeitschrift 

fur deren Gesamtgebiet. Vienna. 

Mikrochimie vereinigt mit Mikrochimica Acta. Vienna. 

Mikrochimica Acta, Organ fur reine 

und angewandte Mikroscopie. Vienna. 

Mineralogical Abstracts. London. 

Mineral'noye syr're. Moscow. 

Mining and Metallurgy. New York, 

N.Y. 

N atl. -Bur. Standards Circ.; Jour. National Bureau of Standards CircuResearch; Tech. News Bull. lar; Journal of Research; Technical 

News Bulletin. Washington. 

Natuurw. Tidjschr ................ Natuurwetenschappelijk Tijdschrift. 

Ghent, Belgium. 

Nuclear Sci. Abs ................. Nuclear Science Abstracts. Oak Ridge, 

Tenn. 

Nucleonics ....................... Nucleonics. New York, N. Y. 

Optical Soc. America Jour. . . . . . . . Journal of the Optical Society of America. New York, N.Y. 

Physica . . . . . . . . . . . . . . . . . . . . . . . . . . Utrecht, Netherlands. 

Redkie metally . . . . . . . . . . . . . . . . . . . Redkie metally. Moscow. 

Rev. Chimica Indus. . . . . . . . . . . . . . . Revista de Chimica Industrial. Rio de 

Janeiro. 

Rev. metallurgie ................. Revue de metallurgie. Paris. 

Rev. Minera, Geologia y Mineralogia Revista Minera, Geologia y Mineralogia. 

Buenos Aires. 

Schweizerische Archiv angew. Wiss. Schweizerische Archiv fur angewandte 

u. Technik Wissenschaft und Technik. Solothurn, 

Switzerland. 
·,·.g .·SE~EC.TE:O .BIBLIOG~APH:IES OF ANALYTICAL .CHEMISTRY 

·:·' Servi,ce geot · Congo. Beige et B.ulletin du . Service · geologique Congo 

Ruanda-Urundi Bull. Beige et Ruanda-U rundi. Leopold-

. . . ville, Eelgian Congo. . 

Sci. and Culture .[India] .· ........ . 

Soc. Chern. Industry [London] Jour.·. 

Soc. chim~ · Fr.ance Bull. ~· ..... : .. ; . 

!·'· i·. 

Science and Culture. Calcutta, India. 

Journal of. the Society of Chemical 

. Industry. London. 

Bulletin de la Societe chimique de 

. France. Paris. 

Soc. sci. Bruxelles Ann ales ....... · Ann ales de la Societe scientifique de 

·South· African indus. Chemist · .... . 

Sovetskaya geologiya ..... ~· .... ; .. . 

Sovetskaya zolotopromyshlennost .. 

S pectrochim. Acta .......... : .... . 

· Staffordshire Iron Steel Inst. Proc. 

Steel · .. · .. ~ : ~ . : . ·. : · .......... : · .. · .. ~ .. 

Sydney Tecii. Con'. Che~.'-Soc. J.~l.ir. and·· ~roc.· . . 

. . Tech .. M~~t .. K~ll:PP ,.Abt . .A; Abt. B . 

. : ~ ; 

·'rids~kr ... Kjemi; · :a.ergv~sen o. · , 

Metallurgi. 

Tohoku .Univ.; Research Inst. Sci. 

. Repts.~ Se:r. A:; . 'Technology 

Repts. · 

.. Univ. Nac. · Litoral Rosario, lnst. 

In:v. ·Microquim. Pub. 

U spekhi khimii ..... : .. ~ ·; ....... . 

K. Vlaam. · Acad. Wetensch. Belgie 

Verh. 

V ses. konf. anal. khimii. Trudy .... 

Bruxelles. Lou vain, ·Belgium. 

The South African Industrial Chemists. 

Sovetskaya geologiya. Moscow. 

Sovetskaya zolotopromyshlennost. 

Spectrochimica Acta. London -

New York. 

Proceedings of the Staffordshire Iron 

and Steel Institute. Stourbridge, Eng-

' hind. · · · 

Steel. Cleveland, Ohio. 

Journal and Proceedings of the Sydney 

''techni~ai: ¢oliege Chemica~ Society. 

Sydney, New South Wales . 

. Technische Mitteilungen Krupp, Abteil 

A, Forschungsberichte; Abteil B, 

. Te.chnische Berichte. Essen, Germany . 

Tidsskrift for Kjemi, Bergvesen og 

. Metallurgi. Oslo, Norway. 

Tohoku University, . Research Institute 

. Scientific .Reports, Series A, Technology Repts. Sendai, Japan. 

Universidad Nacional del Litoral de 

Rosario; Publicaci6nes del Instituto 

de Investigaciones Microquimicas . 

. Rosario, Argentina. 

U spekhi khimii. Moscow. 

Verhandlungen van de Koninklijke 

Vlaamsche Academie voor Weten-

. schappen, Letteren end Schoone 

Kunsten van Belgie, Klasse der Wetenschappen. Brussels. 

Tr.udy .. V sesoyuznoy konferentsii 'po 

. ~p.~Jyticheskoy khimii. Moscow.· 

. ·;~:;tvods~aya 1ab. . .... :· ..... · ....... · Zavodskaya. laboratoriya. Moscow. 

Zeitschr. anal. Chemie . . . ... . . . . . . . Zeitschrift fiir analytische Chemie . 

. _Zeitschr. ang!'lw. Che~ie., .. : .. ...... . 

.~eitschr .. ano.rg. allg .. Chemie 

~ : • ! ··,. 

. M~nich, Germany. 

Zeitschrift fiir angewandte Chemie .. 

Berlin - Leipzig. 

Zeitschrift fiir anorganische und allgemeinische Chemie. Leipzig, Germany. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 9 

Zeitschr. Elektrochemie .......... . 

Zeitschr. N aturforsch. Abt. A; Abt. 

B. 

Zhur. anal. khimii ............... . 

Zhur. fiz. khimii ................ . 

Zhur. obshchey khimii ........... . 

Zhur. priklad. khimii. . ............ . 

Zhur. tekhn. fiziki ............... . 

Zeitschrift fiir Elektrochemie und angewandte physikalische Chemie. 

Berlin, Germany. 

Zeitschrift fiir Naturforschung, Abteil 

A, Arbeiten aus Astro-physik, Physik 

und physicalischer Chemie; Abteil B, 

Arbeiten aus Chemie, Biochemie, 

Biophysik, Biologie und verwandten 

Gebieten. Tiibingen, Germany. 

Zhurnal analyticheskoy khimii. Moscow. 

Zhurnal fizicheskoy. khimii. MoscowLeningrad. 

Zhurnal obshchey khimii. MoscowLeningrad. 

Zhurnal prikladnoy khimii. MoscowLeningrad. 

Zh urnal tekhnicheskoy fiziki. Moscow -

Leningrad. 

BIBLIOGRAPHY 

1 Abramov, F. I., 1938, The decomposition of tantalo-columbates, wolframites, and some rare-earth minerals by sulfuric acid: Mineral. 

syr'ye, no. 1, p. 61-63; cf. Khim. referat. zhur., tom 1, no. 4-5, p. 

87 [Russian]; Chern. Abs., v. 33, p. 57651S. 

An iiwestigation of some contradictory data about the decomposition 

of some rare-earth minerals. 

2 Afanas'yev, B. N. (Afanas'ev) 1941, The question of the existence of 

organometallic compounds of tantalum: Zeitschr. anorg, allg. 

Chemie, Band 245, p. 381-382 [German]; Chern. Abs., v. 34, p. 

78698; v. 35, p. 5455. 

3 Aleksuvskaya, N. V., and Platonov, M.S., 1937, Separation of columbium 

· and tantalum oxides from loparite: Zhur. priklad~ khimii, tom 

10, p. 2139-2142 [Russian, p. 2143 German]; cf. Chern. Abs., v. 

32, p. 32932. 

Fusion of loparite concentrate with KOH completely · separates 

Ta 20 5 and Nb20 5 from Fe. The presence of a very small amount of Ti 

does not interfere with the colorimetric determination of Ta and Nb. 

4 Alimarin, I. P., 1947, Precipitation of. columbium and tantalum in the 

presence of hydroxy acids by means of the condensation products 

·of formaldehyde and phenols: Zavodskaya lab., tom. 13,. p. 547-548, 

[Russian]; cf. Chern. Abs., v. 42, p; 4488d. ' 

Description of technique and methods of precipitation of complex 

compounds of Nb and 'Ta. Precipitate and ignite to oxide at 900°-1000° C. 

6 Alimarin, i:. P., and Burova, T. A., 1945, Quantitative separation of 

columbium and tant~lum with sodium hypophosphite: Zhur. priklad. 

khi~ii, tom 18, p. 289-293 [Russian, English summary]; cf. Chern. 

Abs., v. 40, p. 33621. 

H3 P0 2 forms insoluble complex compounds with Ta ·and Nb in 

presence of tartaric or citric acid. Only Ta precipitates in presence of 

NH4 oxalate. The reaction is specific and applicable to 1:106 concentration. To effect the separation, fuse the mixed oxides with K2S2 0 7, 

dissolve the melt in (NH4 ) 2C2 0 4 solution, and precipitate Ta with 

NaH2P0 2 as (Ta2 0 5 )H(P0 2H2 ). . 

6 Alimarin, I. P., and Frid, B. I., 1937, New method for dete~ting small 

quantities of columbium and tantalum in minerals, rocks, and 

metals: Mikrochemie, v. 23, p. 17-23 [German]; cf. Zavodskaya 

lab., tom 6, p. 823-825 [Russian]; Chern. Abs., v. 20, p. 1574; v. 

27, p. 5673; v. 32, p. 761. 

Niobium and tantalum are precipitated from a sol~tion strongly 

acid with tartaric acid. Titanium and zirconium interfere and can be 

11 
12 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

removed by means of pyrogallol. About 2 micrograms of Nb or Ta 

can be detected in 1 ml of solution. 

7 Alimarin, I. P., and Frim, B. I. 1938, Determination of columbiun and 

tantalum by means of benzenearsonic acid: Zavodskaya lab., tom 

7, p. 913-916 [Russian]; cf. Chern. Abs., v. 32, p. 762; v. 33, p. 16231, 

A preliminary report on the application of reagent to the determination of Nb and Ta in a solution containing a large excess of tartaric 

acid. 

8 --- 1938, Separation of columbium and tantalum from titanium 

and zirconium with the aid of pyrogallol: Zavodskaya lab., tom 7, 

p. 1109-1116 [Russian]; cf. Chern. Abs., v. 32, p. 762; v. 33, 6. 

16231, 20643, 

Full details are given for the determination of Nb and Ta in Ti- and 

Zr-bearing ores, minerals, and silicates by a modified method-using 

pyrogallol, H2S, and benzenearsonic acid separations. Precipitate is 

ignited and weighed as Nb2 0 5+Ta2 0 5 • 

9 -· --.1943; . Determination of columbium and tantalum in minerals 

and ores: Vses. konf. anal. khimii Trudy, tom 2, p. 333-357 

[Russian]; cf. Chern. Abs., v. 39, p. 37519, 1945. 

Modification of the Schoeller method (fuse Nb20 5 with K2S20 7 ; 

dissolve melt in H2C4H4 0 6 , hydrolyze in 30 ml of the solution in the 

· presence of 5 ml of HN03 ) and colorimetric determination of Nb in 

the Ta precipitate. 

10.· Alimarin, I; P., and Podval'naya, R. L., 1946, Colorimetric determination 

of small quantities of columbium as thiocyanate complex: Zhur. 

anal. khimii, tom 1, p. 30-46; cf Chern. Abs., v. 33, p. 20644; v. 39, 

p. 37519; v. 43, p. 2543d. 

Separate 'Ta and Nb oxides; dissolve combined oxides in KHSO 4 • 

H2SO4 ~d the· melt in hot tartaric ,acid; determine Nb with . KCNS 

a:nd SnC12 in HCl; extract complex with ether (yellow). 

Mo, W, U. V, Fe, Cr, Co, Cu, Au, Pt, C2 0 42-, F1-, S042-, P043-, and 

As04B-, interfere. · 

11 American Society for Testing Materials, 1950, Am. Soc. Testing Ma-

·terials methods ·for chemical analysis of metals: Philadelphia, Pa. 

126 p. 

A·. detailed description of the determination of Nb gravimetrically 

by hydrolysis with HC~04 and· H2S03 • Nb. is also determined by 

titration with KMn04 (tantalum by difference). 

12 Argila, J. S., 1950, Photometric methods for the determina.tion of 

elements present in steels: Inf. quimica anal., v. 4, p. 197-205 . 

. Methods are given for deter:mination of Mo, Nb, Ta, _Ti, and V. 

·13.: Atkinson, R. H., Steigman, J., and Hiskey, C. F., 1952, Analytical 

chemistry of niobium and tantalum; critical analysis of existing 

methods: Anal. Chemistry v. 24, p. 477-468~ 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 19{?3 13 

A critical review of the main separative reactions empioyed in the 

analysis of Nb and Ta minerals reveals a number of serious defects. It 

was thought that some could be overcome by developing nonaqueous 

separations. For this purpose, a new atmospheric chlorination method 

was developed, which employs octachloropropane in large excess, 

heated to 300° C. These separations ·lay the groundwork for a new 

system of analysis of the niobite minerals. Ti and Sn are also separated by chlorination and Aistillation. Fe20 3 must be removed because 

it decomposes the chlorinating agent c81talytically. 

14 Bachelet, M., and Bouissieres, G., 1947, Separation ·of protoactinium 

from its entrainers-titanium, zirconium, and tantalum: Soc. chim. 

France Bull., p. 281-283; cf. Chern. Abs., v. 41, p. 7247g. 

The authors describe the principal methods of fractionation and ·of 

separation of Pa ·from its entrairiers Ti, Zr, and Ta an~ detail more 

particularly the fractionation processes of crystallization of double 

fluorides, the precipitation of hydroxides, and some separations by 

chemical reactions. 

15 Bagshawe, I. B., 1936, Modern methods of alloy steel analysis: Staffordshire Iron and Steel Inst. Proc., v. 52, p. 116-142, 193~37; cf. Chern. 

Abs., v. 31; p. 52957; v. 32, p. 41024. 

A review · of the modern technique for analyzing alloy steels, 

with special consideration of the determination of Mn, Cr, Co, Ce, Ti, 

Cu, Mo, AI, N 2 , As, Nb, Ta, Zr, Se, and Be. 

16 Bagshawe, I. B., and Elwell, W. T., 1947, Determination of columbium 

in rustless and heat-resisting steels: Soc. Chern. Industry [London] 

Jour., v. 66, p. 398-402; cf. Chern. Abs., v. 42, p. 2541b. 

Application of classical methods to separate (Nb,Ta) 2 0 5 • Ti0 2, 

followed by colorimetric H2 0 2 determination of Ti. An examination of 

six methods was made with respect to Nb analysis. 

17 Bailey, N. H, 1951, Determination of tantalum and niobium: South 

African Indus. Chemist, v. 5, p. 235-236; cf. British Abs~, v. C, no. 

1814, 1952. 

The method described for determination of Ta and Nb in ores depends 

on the ·difference in stability of solutions of their oxides in aqueous 

NH4 oxalate. Niobic acid and its salts are much more readily soluble 

than tantalic acid in aqueous oxalic acid solution. Separation of Ta 

and Nb is effected by treatment with tannic acid, which is added to 

the solution at pH 5 (buffered with NH4 oxalate) when a yellow Ta 

complex is precipitated. Mter this has been filtered off, the filtrate is 

rendered ammoniacal, when the red Nb-tannic acid complex is precipitated. 

18 Barber, H., 1947, Determination of columbium and tantalum in basic 

Bessemer slag: Berg. u. htittenm. Monatsh. Montan. Hochschule 

Leoben, Band 92, p. 114-115; Chern. Abs., v. 42, p. 870la. 

The procedure recommended does not provide for separating Nb and 

Ta. Following classical separations, the final precipitate is fused with 
14 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY · 

-· ·KHS04, the melt is digested with water and H2S03, and the insoluble 

_residue ignited and weighed as Nb20 5+Ta20 5• 

. . 

19. · Barber, E. J., Farrar, R. L., Junkins, J. H., and Bernhardt, H. A., 1950, 

· Physi<;al constants of niobium pentafluoride: K-652, 27 p.; cf. 

· Nuclear Sci. Abs., v. 4, p. 961 (no. 6568) . . t' 

20 Beck~ G., 1937, Detection of indium with morin and some heavy metals 

:with cacothelin: cf. Mikrochimica Acta, Band 2, p. · 287-290; cf. 

Chern. Abs., v. 32, p. 16067. 

The formation of a colored dyestuff by the reduction of cacotheline_ · 

is accomplished not only by Sn++ but also by TiS+, V02 +_+, Rh3+, low. 

o:x.ides of Mo and W, and NbCl3 • About 1 microgram of any of these 

elements giv~s the test. · ' 

21· Bhattacharya, .H;, 1950, Analytical separation of Jliobium and tantalum: 

Sci.· and Culture [India], v. 16, p.· ·69-'(0; cf. Chern. Abs., y. 45, 

p. 3287b, 1951. 

Study of the effect of oxalate concentration and pH on the precipitation of Ta- and Nb-tannin complexes. Co.ntrol of .pH effects complete 

.. ·.separation. ' 

22 --- 1952, Investigations on the analysis of· mixed- oxides of the 

elements of group Va and IVa; [Pt.] !-Preparation of pure 

tantalum and niobium pentoxide from Indian columbite and their 

analytical separation: Indian Chern. Soc. Jour., v. 29, no. 11, p. 

871-879. . . 

23 Birks, L. S., and Brooks, E. J., 1949, Quantitative analysis of Hf-Zr 

and Ta-Nh systems by X-ray fluorescence: NRL-3720, (AEC file 

no. NP-13'71); cf. Nuclear Sci. Abs., v. 4, p. 692 (no. 4562), 1950. 

The. X-ray fluorescence analysis method was adapted to the determi-

'nation of small amounts of Hf in Zr and Ta in Nb. Curves of relative 

intensity of spectral lines of Ta and Nb or Hf and Zr were plotted 

against percent composition· by using prepared standard composition. 

24 --- 1950, Hafnium-zirconium and tantalum-columbium systems; 

Quantitative analysis by X-ray fluorescence: Anal. Chemistry, v. 

22, p. 1017; Nuclear Sci. Abs., v. 4, p. 841 (no. 5646). 

Tpe X-ray fluorescence analysis method was adapted to the determintaion of small amounts of hafnium in . zirconium and tantalum in 

columbium. Curves of the relative intensity of spectral lines of Ta and 

Nb or Hf and Zr were plotted against percentage composition by using 

prepared standard compositions. As an example of accuracy attainable, 

with a counting time of 3 to 5 minutes on a 0.5 atomic percent specimen of Ta in Nb, the probable error in Ta content due to statistical 

fluctuations of the Geiger counter was 0~02, or 4 percent of the 

amount present. 

25 Bleyenheuft, L., 1936~ Comparative study of different ·analytic methods 

of determining tantalum and columbium: Ingenieur chimiste, v. 

20, p. 165-185 [French]; cf. Chern. Abs., v. 24, p. 1055; v. 25, p. 51; 

v. 31, p. 38174. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 195~ 15 

The quantitative reactions are reviewed and the results obtained 

on samples of pure Ta and Nb using the different methods are tabulated. Methods of separating Ta and Nb in minerals from Si02, Sn02, 

Ti02, W03, FeO, and MnO are reviewed and the results shown. A 

bibliography of 36 references is given. · · 

26 Blinov, V. 1., 1948, Determination of niobium in stainless steel with 

the aid of the steelscope: Zavodskaya lab., tom: 14, p. 14~4-1595 

[Russian]; cf. Chern. Abs., v. 46, p. 7931g. 

Use of the Nb lines 5095.3 and 4573.1 A is recommended. With the 

line 5095.3 A it is advantageous to use the Fe line 5098.7 A for comparison. For steel containing 1.5 percent Nb, the intensity of the Nb 

line 5095.3 A is equal to the intensity of the Fe line, whereas the 

intensity of the Nb line 4573.1 A is close to the intensity of the Cr 

line 4569.6 A. 

27 Blokhin, M. A., 1945, X-ray spectral analysis and its possibilities: 

Zavodskaya-lab., tom 11, p. 1069-1074 [Russian]; d. Chern. Abs. 

v. 40, p. 70438. ' 

A review is given of X-ray spectral analysis of elements, beginning 

with Mg and ending with U. Methods are discussed for the analysis 

for ores, minerals, and products of concentrating and metallurgical 

plants, and for the separation of rare elements. 

28 Borneman-Starinkevitch, I. D., 1939, Decomposition of cassiterite by 

fusion with borax and some details of its complete chemical 

analysis: Acad. sci. U. R. S. S. Comptes rendus, v. 24, p. 353-356; 

cf. Chern. Abs., v. 34, p. 9637, 

29 Borovskii, I. B., 1937, Analysis of minerals by the X-ray spectroscopic 

method: Akad. nauk SSSR lzv., ser. geol., vyp. 122, p, 929-936; 

cf. Mineralog. Abs., v. 7, p. 215; Chern. Abs. v. 33, p. 37182. 

This method applied to various Zr and Ta silicates shows the 

presence in zircons of Hf, Sr, and Th, and in eudialytes of Y, Sr, aud 

Ta. 

30. --- 1939, Methods of X-ray spectroscopy: Vses. konf. anal. khimii 

trudy, tom 1, p. 135-42; cf. Khim. referat. zhur., no. 2, p. 57, 

1940. Chern. Abs. v. 28, p. 29942; v. 26, p. 1510; v. 33, p. 1191; 

v. 35, p. 20894; v. 3_6, p. 12578. 

X-ray spectral analysis (determinations) carried out according to 

the method of equalization of the intensities, and methods for determining Nb, Ta, Zr, Hf, Zn, Sr, Th, U, Ce, La, Nd, Y, and Mn were 

developed. The determinations differ by 5 to 20 percent from true value. 

31 Borovskii, I. B., Blokhin, M. A., and Glzhibovskaya, L. A., 1940, X-rayspectroscopic quantitative and qualitative analysis of the rare 

elements:· Akad. nauk SSSR Izv., Ser. fiz., tom 4, p. 122-124; cf. 

Chern. Abs., v. 26, p. 1510; v. 28, p. 29942; v. 35, p. 474, 20895. 

Various minerals and ores were analyzed for the rare elements with 

th~ X-ray s:pectro~raph and with ~ bent crrstal. f~~ ~he speciall¥ 
lEf SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

prepared mixtur~s of pure elements ( standa~ds) the relation be-

' tween 'the intensity of lines and the concentration of Mn, Cr, Sr, Y, 

· ·Zr, Nb, Co, Ce, La, Pr, Nd, .Ta, W, Ph, Th, and U was fo~nd. 

32 Bouissieres, G., 1941, Electrolytic fractionation of tantalum oxide containing protoactinium: Jour. physique et radium, tome 8, no. 2, p. 

72; cf. Chern. Abs., v. 40, p. 17397. 

33 Breckpot, R., and Creffier, J., 1937; Spectrographic determination of 

and tantalum: Soc. sci Bruxelles Annales, ser. 1, v. 57, p. 290-295; 

c~. Chern. Abs., v. 32, p. 24529. 

Nb and Ta content can be determined in the presence of as much 

as 9.1 percent Ti. 

34 British Aluminium Co., Ltd., ·1941, Analysis of aluminum and its 

alloys: British Aluminium Co., Ltd., Pub. 399, p. 186; cf. Chern. 

Abs., v. 36, p. 47725 

. The methods of sampling and analysis used in company's laboratories 

are described. The application of photometric methods, polarographic 

methods, and other . classical techniques are given in detail. 

36 Brode, Wallace R., 1943, Chemical spectroscopy: 2d ed;, New York, 

John Wiley and Sons. p. 472. 

Spectrum tables (principal lines of Nb). 

37. Brubacker, C. H.,. and Young, R, C., 1951, Anhydrous NbBr3 and 

· ~bCl : Am. Chern. Soc. Jour., v. 73, p. 4179. 

Preparation and properties . 

. 38 Bruning, K., Meier, K., and Wirtz, H., 1939, Determination of tantalum 

~nd cqlumbium in ferrotantalum, ferrocolumbium, and ferrotanta1ocolumbium: Metall. u. Erz;, v. 36, p. 551-554; cf. Chern. Abs., v . 

.34, p. 12729. 

Oxides of Nb and Ta are determined , first, then the Nb and . 'ra are 

separated by a crystallization method based on the work of M~rignac. 

39 .. Budanov:a, L. M., and Gavrilova, K. D., 1~49, Determination of tungsten 

.. and' columbium· in steel: Zavodskaya lab., tom 15, p. 7-11; cf. 

Chern. Abs., v. 43, p. 5335e. 

Niobium and tungsten can be separated by cupferron in presence 

of fluoride. Tungsten can be determined by complex formation with 

thiocyanate, after reduction, even in presence of 3 percent Mo. Niobium 

is determined ~s the oxide . 

. 40 Burstall, F. H., Swain, P., Williams, A. F., and Wood, G. A., 1952, 

Inorganic chromatography on cellulose; [Pt.] 11-A study on the 

separation of tantal~m from niobium and its application to 

quantitative· analysis;· Chern. Soc. [London] Jour. p. 1497-1504; 

cf. Nuclear Sci. Abs., v. 6, p. 496 (no. 4018); Chern. Abs., v. 47, 

p. 1537d/, 3753i. 

The ·method of separation is based on , their extraction in turn as 

·fluorides, ·by ethyl methyl ketone in the presence of cellulose abs'orbent. 
.NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 ~7 

Tantalum is extracted first with ethyl methyl ketone saturated with 

water. Niobium is then extracted with the same organic solvent containing 7.5 percent (volume per volume) of HF ( 40 percent aqueous 

solution). It has been shown that, so long as the amount of Ta present 

does not exceed that of Nb, a sharp and quantitative separation is 

obtained. 'The method has been applied to the separation of the earth 

acids from their mixtures with other metal ions, and to the determination of Nb and Ta in minerals and alloys. 

41 Burstall, F. H., and Williams, A. F., 1952, Inorganic chromatography 

on cellulose; [Pt.] 11-The quantitative determination of tantalum 

and niobium in high- and low-grade complex minerals and ores: 

Analyst, v. 77, p. 983-999. 1 

A new chromatographic method, based on cellulose as adsorbent 

and · ethyl methyl ketone containing hydrofluoric acid as solvent, is 

described for the quantitative separation of tantalum from niobium 

and for their. determination in minerals, ores, and synthetic materials. 

From a solution of the sample in hydrofluoric acid containing ammonium fluoride, tantalum is extracted first in a volume of 250 ml of 

ethyl methyl ketone saturated with water. The column of cellulose 

is then washed with ethyl methyl ketone containing 1 percent volume 

per volume of hydrofluoric acid ( 40 percent weight per weight aqueous 

solution of hydrogen fluoride) which arrests the movements of titanium, 

tin, and zirconium. Niobium is then extracted with the same organic 

solvent containing 12.5 percent of hydrofluoric acid. After removal of 

solvent, the tantalum and niobium are usually determined in the 

appropriate fractions by ignition to pentoxides. 

If phosphate ions are present in the original sample, phosphoric 

acid is extracted by the solvent used for extraction of niobium; 

hence the procedure for the final determination of niobium involves 

a separation of niobium from phosphate ions. Ammonium hydroxide 

has been successfully used for this purpose. 

Owing to the large amount of sample that is necessary for the 

analysis of a low-grade ore, chemical treatment of such samples is 

made before chromatographic extraction. This treatment involves the 

separation of the earth acids together with small amounts of other ions 

by ·hydrolytic precipitation in acid solutions. 

The procedures are simple and accurate and have been used for the 

analysis of a wide range of natural and synthetic materials. 

42 Bykova, V. S., 1938, Quantitative separation of columbium and titanium: Acad. sci. U. R. S. S. Comptes rendus, v. 18, p. -655:....657 

[English]; cf. Chern. Abs., v. 32, p. 61728. 

After an initial HF attack, the sample is g:lven a pyrosulfate-tannin 

treatment to remove Ti. The values obtained for Nb20 5 are 2-4 mg 

under the true value. With Schoeller's oxalate-salicylate method (Chern. 

Abs., v. 26, p. 1875) in separating Nb and Ti, a similar loss is obtained. 

43 --- 1940, Determination of columbium and tantalum in loparite ores 
18 SELECTED BIBLIOGRAPHIES OF ANALYT!CAL CHEMISTRY 

and concentrates: Zavodskaya lab., tom. 9, p. 1193-1196; cf. Chern. 

Abs., v. 35, p. 28111. 

A new method proposed for determining Nb and Ta in loparite ores 

and concentrates by leaching with hydrochloric acid solution of tannin 

is to determine Ti0 2 colorimetrically and subtract from the total 

weight of Ti02 , Nb2 0 5 , and Ta2 0 5• 

44 --- 1940, The separation of columbium from titanium: Akad. nauk 

SSSR, Trudy Kol'skaya baza, tom 5, p. 77-92; cf. Khim. referat. 

zhur., v. 4, no. 2, p. 61, 1941; Chern. Abs., v. 37, p. 30086. 

The most important old methods are reviewed and the best modern 

methods for the separation of the mixture Nb + Ta from Ti described 

in detail. 

45 Carriere, E.,_ and Guiter, Henri, 1943, Action of V20 5 and Cb20 5 on 

alkali carbonates and sulfates: Acad. sci. [Paris] Comptes rend us, 

v. 216, p. 568-569; cf. Chern. Abs.; v. 38, p. 22818, 1944. 

Practically all of the compounds formed were soluble in water and 

fusible. 

46 -.-- 1945, Volumetric methods for the analysis of complex salts: 

Soc. chim France Bull., tom 12, p. 75-77; cf. Chern. Abs., v. 40, 

2876. 

A discussion of methods which have been found useful for the rapid 

determination of Cr, Mo, Nb, W, V, and U in their complex salts. 

47 Chernikhov, Yu. A., and Goryushima, V. G., 1945, A review of contemporary analytical chemistry of tantalum and columbium: Zavodskaya lab., tom 11, p. 875-886; cf. Chern. Abs., v. 40, p. 70584 

The paper discusses the separation of earth acids from other elements 

and gravimetric methods of their determination, volumetric methods 

for the determination of Ta and Nb, color reactions for Ta and Nb 

and colorimetric methods of their determination, and analysis of ores, 

concentrates, ferroalloys, and steel for Ta and Nb. 

48 Chernikhov, Yu. A., and Karsayevskaya, M. P., 19'34, Determination 

of tantalum and niobium in wolframite: Zeitschr. anal. Chemie, 

Band 98, p. 97-98. 

Application of tannin method to the determination of· small amounts 

of Nb and Ta in wolframite. 

48a --- 19·38, Volumetric determination of columbium: Zeitschr. anal. 

Chemie, Band 99, p. 398-402; cf. Chern. Abs., v. 28, p. 63876; 

v. 29, p. 13581. 

Careful experiments show wide variations in attempts to obtai11 

correct Nb values by the method of Schwarz (Che_!ll. Abs., v. 38, p. 

40036). 

49 Claffy, E. W., 1949, The polarographic method for determining trace 

elements in rocks and minerals: Am. Jour. Sci., v. 247, p. 187-199; 

cf. Nuclear Sci. Abs., v. 2, p. 356 (no. 1595). 
'NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 19 

. . This ·method is applicable to about forty elements, among which are: 

· Ra, Ti; Zr, V, Nb, U, and Ge. Range is about O.X percent to O.OOOX 

percent. 

50 Colin, L. L., 1950, The use of tannin in chemical analysis: Chem. Metall. 

Min. Soc. South Africa Jour., p. 314-319; cf. Nuclear Sci. Abs., 

v. 4, p. 960 (no. 6565). 

Analysis· of tantaloniobates, U, separation of Ti from V, and separation of U from Ti are discussed. 

51 Cordovi, M. A., 1948, Rapid quantitative analysis by X-ray fluorescence: 

Steel, v. 123, no. 25, p. 88-94; cf. Chem. Abs., v. 43, p. 959, 1949. 

A progress 1·eport indicating that a few modifications in present 

equipment will bring the accuracy within limits required in routine 

determinations of 'Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Ga, Ge~ As, Se, 

Be, Rb, Sr, Y, Zn, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, and Sn. 

52 Cottin, Maurice, 1950, Isotopic exchange between Co and Ta and their 

ions in solution: Acad. sci. [Paris] Comptes rendus, tom 231, p. 

697-699 [French]; cf. Nuclear Sci. Abs., v. 5, p.12 (no. 80), 1951. 

53 Cottin, M., and Haissinsky, M., 1950, Electrochemical potential in 

hydrofluoric acid solution and electrolytic polishing of niobium: 

Jour. chimie physique, tome 47, p. 731-732 [French]; cf. Nuclear 

Sci. Abs., v. 5, p. 433 (no. 2689), 1951. 

54 Creffier, J., 1938, Spectral. analysis of columbium and tantalum: 

Natuurw. Tijdschr. [Belgium], Jaarg. 20, p. 63; cf. Chem. Abs., 

v. 33, p. 41557. 

Optimum conditions are described for the spe.ctographic determination of Nb and Ta to an accuracy of 1.5 percent with a Hilger Fd-60 

spectograph. 

55 Cropper, F. R., and Hamer, A., 1949, A review of infrared spectroscopy 

in analytical chemistry: Anal. Chim. Acta, v. 3, p. 169-179; cf. 

Chem. Abs., v. 43, p. 8297. 

56 Cunningham, T. R., 1938, Determination of columbium and tantalum in 

stainless steel: Indus. Eng. Chemistry, Anal. Ed., v. 10, p. 233-235; 

cf. Chem. Abs., v. 32, p. 44619. 

Detailed directions are given for carrying out the determination by 

precipitation of Nb and Ta with cupferron and also by a modification 

of the Schoeller and Powell ( Chem. Abs., v. 22, p. 2899) tannin procedure. Nb20 5 + Ta20 5 are precipitated, ignited, and weighed. Treatment of a solution of the oxides with H2 0 2 and succinic acid reduces 

Nb to trivalent state, whereas Ta remains pentavalent. 

57 Davydov, A. L., Vaisberg, Z. M., and Burkser, L. E., 1947, Photometric 

method for determining columbium in steel: Zavodskaya lab., tom 

13, p. 1038-1043; cf. Chem. Abs., v. 43, p. 4177e. 

· 'The blue complex Nb with phosphomolybdate is most intense when 

the solution is 0.4 - 0.7 N in H2S04 ; the color is independent of the 
20 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

excess of SnC12 used; phosphate above 0.05 mg does not affect color 

intensity (below 0.05 mg color is weaker). Mn, Cr, Ni, Si, and C do 

not affect the result, which will agree within 0.01 - · 0.02 percent of the 

true value. 

58· Delaney, J. C., and Owen, L. E., 1950, The spectrochemical analysis 

of bismuth matrices employing the porous electrode technique: 

NEPA-1424; cf. Nuclear Sci. Abs., v. 4, p. 655 (no. 4291). 

A spectrochemical procedure for the analysis of Be, Co, Cr, ·Fe, Mn, 

Mo, Nb, Ti, Ta, V, and W in bismuth matrices is described. The technique developed· calls for the excitation in a porous cup electrode of 

solutions representing the dissolved sample and containing an added 

internal standard element. Analytical curves were obtained by means 

of standard solutions prepared and excited in a manner analogous to 

that of the samples. 

59 Doan, Ursula M., and Duval, Clement, 1957, Thermogravimetry of 

analytical precipitates; [Pt.] 57-Determination of niobium: Anal. 

Chim. Acta, v. 5, p. 81-83 [French]; cf. Chern. Abs., v. 46, p. 

7466b. . 

Pyrolysis curves of precipitates used for the gravimetric determination of Nb show that none of them can be recommended. 

60 --. -1951, Thermogravimetry of analytical precipitates; [Pt.] 58-

Determination of tantalum: Anal. Chim. Acta, v: 5, p. 135-137 

[French]; cf. Chern. Abs. v. 46, p. 7466c. 

Pyrolysis curves show that the pest method for the gravimetric 

determination of Ta is the one employing tartaric acid. The Ta 0~ 

precipitate is stable above 894 o C. 

61 Dobina, A. A., and Platonov, M. S., 1941, Color reactions. for columbium 

and tantalum: Zhur. priklad. khimii, tom 14, p. 421-422; cf. 

Chern. Abs., v. 36, p. 24979. 

Authors state that the colorimetric tests for Nb and Ta proposed 

by Shapiro (Chern. Abs., v. 33, p. 16241) are unsatisfactory because 

of low sensitivity. Previous studies of color reactions are in Mikrochim. 

Acta, v. 3, p. 144-146, 1938, and in Zhur, priklad. khimii, tom 11, v. 11, 

p~ 1029, 1938. 

62 Dunham, Helen S., and Fred, Mark, 1951, Determination of tantalum, 

zirconium, and hafnium in columbium by the porous graphite 

method: AECD-3102; ANL-HDY-582; cf. Nuclear Sci. Abs., v. 5, 

p. 490 (no. 3055) . 

Densitometdc procedure and a method for concentration of Ta in 

Nb are described. 

63 Edwards, J. W., Speiser, Rudolph, and Johnston, H. L., 1951, Hightemperature structure and thermal ·expansion of some metals as 

determined by X-ray diffraCtion data; [Pt.] 1-Platinum, tantalum, 

niobium, and molybdenum: Jour. Applied Physics, v. 22, p. 424-428; 

cf. Nuclear Sci. Abs., v. 5, p. 548 (no. 3431). 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 21 

64 Eferidiev, F. M., 1947, Combined spectral and chemical analysis of 

microelements: Akad. nauk SSSR Izv., Ser. fiz., tom 11, p. 313-818; 

cf. Chern. Abs., v. 42, p. 1843/. 

A study of the determination of small amounts of elements in soils, 

ores, and other materials by chemical concentration and spectrographic 

analysis. 

65 Eichholz, G. G., 1952, Activation assaying for tantalum ores: Nucleonics, v. 10, no. 12, p. · 58-61; cf. Chern. Abs., v. 46, p. 7468a; 

v. 47, p. 2638g. 

66 Elson, Robert E. 1953, The solution chemistry of niobium and tantalum; 

[Pt.] 2-Spectra of some niobium and tantalum complexes: 

UAC-712, February; cf. Nuclear Sci. Abs., v. 7, p. 339 (no. 2785). 

Qualitative and semiquantitative results obtained in the spectrophotometric study of Nb and Ta complexes (the perchlorate, chloride, 

tartarate, and fluoride systems) are presented. 

67 -- 1951, Reduction of niobium (V) and (IV) and tantalum (V) 

in" solution: AECU-1384; UAC-357; cf. Nuclear Sci. Abs., v. 5, 

p. 733 (no. 4674). 

68 Estartus, Francisco Garcia, 1944, Separation of columbium and tantalum; 'Treatment of columbites and tantalites: Afinidad, v. 21, 

p. 400-405; cf. Chern. Abs., v. 41, p. 1947i. 

The ·-history and sources of Nb and Ta are given, together with all 

known methods for their separation, purification, and analysis. 

69 Evans, B. S., and Box, F. W., 1943, Analysis of WC tips: Analyst v. 

68, p. 203-206; cf. Chern. Abs., v. 38, p. 57502, 1944. 

Provision is made for determining Nb and Ta. 

70 Fairbrother, F., and Frith, Wm. C., 19'51, The halides of niobium and 

tantalum; [Pt.] 3-The vapor pressure of niobium and tantalum 

pentafluorides: Chern. Soc. [London] Jour. p. 305i-3056; cf. Chern. 

Abs., v. 44, p. 2879/; v. 46, p. 4871g. 

The vapor pressures of NbF 5 and TaF 5 were measured by a static 

method using a Bourdon-type sickle gage and by boiling-point determinations under a number of controlled pressures. Thus for NbF 5, mp = 

80.0° and bp = 234.9° C; and TaF 5 , mp = 95.1 o and bp = 229.2° C. 

71 Fedorov, A., 1940, Determination of titanium, columbium, and zirconium in steel alloys by means of a steeloscope at the plant "electrostal": Akad. nauk. SSSR Izv., Ser. fiz., tom 4, p. 212-215; 

cf. Chern. Abs., v. 35, p. 17258. 

A semiquantitative method of analyzing steel alloys for Ti, Nb, and 

Zr by means of a steeloscope is developed (spectroscopic method). 

72 Fink, Colin G., 1937, Rare metals and minerals; pure electrolytic manganese produced; vacuum tubes important outlet for some metals: 

Mining and Metallurgy, v. 18, p. 22-25, Chern. Abs. v. 31, p. 21027. 
22 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

A review of the progress during 1936 in the chemistry and metallurgy 

of Sb, Be, Cd, Ca, Ce, Rb, Cu, Nb, Ta, Ga, Ge, In, Li, Mg, Mn, Hg, Mo, 

Mo, 'Th, Pd, Pt, metals, Po, Ra, U, Se, Te, N a, Ti, W, and Zr. 

73 Fleischer, Michael, and Harder, J. 0., 1946, The geochemistry of 

columbium and tantalum: MDDC-644, 28 p. 

74 Fowler, R. M. (by mesne assignment to Union Carbide and Carbon 

Corp.), 1949, Separation of columbium and tantalum: U.S. patent 

2,481,584, Sept. 13, 1949; cf. Chern. Abs., v. 44, p. 527i, 1950. 

76 Freund, H., and Levitt, A. E., 1951, Colorimetric determination of 

niobium with thiocyanate: Anal. Chemistry, v. 23, p. 1813-1816; 

cf. Nuclear Sci. Abs., v. 6, ·p. 146 (no. 1143), 1952. 

This paper describes a colorimetric method based on the yellow 

color of a niobium thiocyanate complex. The color system is stabilized 

by using high concentrations of acid, chloride, thiocyanate, and miscible 

solvent. The absorbancy of the complex follows the Beer-Lambert law 

in the concentr:;~.tion range up to 3.5 mg of Nb per mi. Interferences 

and means of minimizing them are discussed. 

77 Fucke, H., and Daublander, J., ·1939, Determination and separation of 

columbium and tantalum in steel by precipitation with benzenearsonic acid or sodium bicarbonate with addition of hydrogen peroxide: Tech. Mitt. Krupp Forschungsber., Band 2, p. 174-178, cf. 

Chern. Abs., v. 34, p. 404. 

Two methods for separation of Nb and Ta are described. One is 

·based on precipitation of Ta in H20 2-containing H 2S04 solution with 

benzenearsonic acid; Nb stays in the solution, from which it is precipitated later by benzenearsonic acid after destruction of the H20 2 •• 

The other method separates the acids of the earth metals in H2 0 2-

containing H 2S04 solution with NaHC03 ; Ta precipitates first and 

Nb is separated in the filtrate with H2SO4 • A third method describes 

the simultaneous separation of Nb and Ta in steel by determining the 

Si02 content at the same time. 

78 Funk, H., and Baumann, W., 1937, Reactions of a few metallic chlorides 

with phenol and B-naphthol: Zeitschr, anorg. allg. Chemie, Band 

231, p. 264-268; cf. Chern. Abs., v. 31, p. 38089. 

79 Furey, J. J., and Cunningham, T. R., 1948, Analysis of simple and 

complex tungsten carbides: Anal. Chemistry v. 20, p. 563-570; cf. 

Chern. Abs., v. 42, p. 5798a. 

Methods for separation and determination of Nb, Ta, Ti, W, Co, Ni, 

Fe, Si, Mn, and C are described. Nb and Ta are separated by precipitation with NaOH, followed by regulated hydrolysis and final precipitation with cupferron. 

80 Gatterer, A., and others, 1945, Atlas of persistent spectra; [Pt.] 3-

Spectra of rare metals and some metalloids: Vatican City, Astrophys. Lab. Vatican Observatory; 10 p. cf. Chern. Abs., v. 44, p. 

1930, 1950. ' 

Arc and spark spectra are given. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 23 

81 Geld, I., and Carroll, J., 1949, Colorimetric determination of columbium 

and tungsten in high-temperature alloys: Anal. Chemistry, v. 21, 

p. 109'8-1101; cf. Chern. Abs. v. 43, p. 8950i. 

Nb is determined as yellow perniobic acid produced by adding H2 0 2 

to a solution of Nb20 5 in concentrated SO~ and W as the yellow 

thiocyanate resulting from the action of SnC12 and KCNS solutions. 

82 Gentry, C. R., and Sherrington, L. G., 1948, The photometric determination of tungsten: Analyst, v. 73, p. 57, 1948. 

In the colorimetric determination of W with · KCNS, Nb interferes 

seriously. Complex is extracted with organic solvents. 

83 Gest, H., and Glendenin, L. E., 1951, Coseparation of aqueous fission 

products with manganese dioxide, in Coryell, C. D., and Sugarman, 

Nathan, eds., Radiochemical studies-The fission products, Book 1 

(Natl. Nuclear Energy Ser., Div. IV, v. 9): New York, Atomic 

Energy Comm.-McGraw-Hill Book ·co., p. 170-175; cf. Chern. 

Abs., v. 47, p. 5839/. 

In dilute HN03, Mn0 2 is effective as a general scavenger for the 

fission-products elements Nb, Te, Zr, and possibly others. In acid concentrations above 10 M, Nb, Te, and Mo are specifically removed. The 

coseparation of Nb95 with externally formed, freshly precipitated wet 

Mn02 in 10 M HN03 is quantitative after 30 minutes of contact. 

84 Gibson, K. S., 1949, Spectrophotometry (200 - 1000 m mu): Natl. Bur. 

Standards Circ. 484; cf. Chern. Abs., v. 44, p. 27, 1950. 

A review with 127 references. 

85 Gilbert, Paul T., Jr., 1952, Flame photometry-New precision in elemental analysis: South Pasadena, Calif., Beckman Instruments. 

Determination of alkalies, alkaline earths, Nb, and other materials. 

86 Giles, W. B., 1907, Observations on niobium, tantalum, and titanium: 

Chern. News, v. 95, p. 37. 

Reduction of Nb in H3P04 solution with Zn. 

87 Gillis, J., 1944, Critical study of reagents for cations (vanadium, 

columbium, tantalum): Mikrochemie ver. Mikrochim. Acta, Band 

31, p. 273-285; cf. Chern. Abs., v. 38, p. 19796. 

Tests are given for the detection of Nb and Ta. 

·88 Gillis, J., and Eeckhout, J., 1947, Quantitative spectrochemical analy~is 

of steel: Anal. Chim. Acta, v. 1, p. 377-389; cf. Chern. Abs., v. 

42, p. 4493i. 

Operating conditions are described for the spectrographic analysis 

of Fe steel and C steel. Technique based on the Scheibe and Rivas method. Analysis line and standardizing tables are given for Ni, Mn, Cr, Co, 

Ti, AI, Mo, V, Zr, As, Cu, Nb, and Ta. 

89 Gillis, J., Eeckhout, J., and Poma, K., 1944, Separation of columbium 

and tantalum with ferroin in hydrogen fluoride solution: K. Vlaam. 
. :~4 ~~LE9TED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

. A~ad. Wet~nsch. Belgie.; Verh .. "Y· .6, no. 10, p. 5-10; cf. Chern. Abs., 

. v. 40, p. 43141. . 

Repeated precipitation· and solution of the· salts' in HF solution 

. with ferro in. is a useful method for separating Ta al).d Nb. 

· 90 ·. Giratto, A.; 1940, ·Scheme · for analysi.s of samarskite:' Rev. Chimica 

.Indus.,' ano .9, no. 104, p. 10-2 cf. Chern. Abs., v; 35, p. 35576, 

:Determination of rare earths, Th, U, Ca, Mg, Nb, .Ta, Ti, Zr, Fe, and 

Mn, in samarskite is described. . 

91 · Goldbersuch~ ·E., and Young; R; C., 1949, Complex sulfates containing 

Nb3+ and Nbfi+ and the possibility of their use in the purification 

of niobium: Am. Chern. Soc. Jour., v. 71, . p. 2402-2405. 

92· ··G.olubtsova, R: B., 1951, Determination· .o;f niobium in high-alloy steels 

free of tungsten: Zhur. anal. khimii,: tom 6,. p. ·34-38. · 

' '. · . ."•. Nb~O~ is 'determined colorimetrically with hydrogen peroxide. ~ .. . .. . . . ' . . . . . 

93 --- 1951, Determination of tungstep and .niobi~m in ·high-:-alloyed 

alloys: Zhur. anal. kh~mii, tom .6, .P· 357-363.; cf. Chern. Abs., v. 

'-. _46, I?·· 2~57a. ·. . · 

' Determina~ion ·of Nb with.· tannin and gallic add . . • ;, 1 • • ' •. - . • • • • • 

. 9'4 ·, -Gorba.ch, _ q., · and Pohl, F.; .1951, Concentration and spectroscopic 

determination· of trace- metals; [Pt.] !-Extraction. with organic 

reagents: Mikrochemie ver. Mikrochim. Acta, Band 38, p. 258-267; 

cf; British Abs., v. 1C, p. 30· (n~. 232) i952= · 

Er~ors due to' precip"itation and 'electrochemi~al techniques for the 

concentration of trace metals prior to spectroscopic determination are 

avoided by extraction methods. Studies w~th the following reagents 

capable of. forming C;IJClg-Solution metallic complexes are detailed: 

1-benzoinoxine~ dithizone, isonitrosoacetophenone, cupferron, 2-nitroso1-naphthol, 8-hydroxyquinoline, salicylaldoxine, and thionalide, in conJ;t;~nction with the fol,lowing metals: Ag, AI, As, Au, Bi, Cd, Ce, .Co, Cr, 

Cr, Cu, Fe, Fe," Ga, Hg, In, Mn, Mo, Nb, Nf, Os, Ph, Pd, Pt, Sb, Sn, 

Ta, Th, Hi, Tl, V, W, Y, Xo, arid Zr. Qu.alitative and quantitative 

examination is affected by sparking the extra'cts,' precipitate, and 

residual sqlutions after each extraction. In. general, successive extrac-

. ti9~ with two reagents is necessary for the collection of" the above trace 

.·;I metals, dithizone and 8-hydroxyquinoJine being preferred. 

95 Goto, Hidehero, and Kakita, Yachiyo, 1950, Colorimetric determination 

of niobium and tant"alum: Tohoku Univ., Research Inst. Sci. Repts., 

: Ser. A, v. 2, p. 249-254; cf. Chern. Abs., v.· 45, p. 7913i, 1951. 

Determination of Nb ·based on the yellow color formed with pyrogallol 

and Na2S03 at pH 4.6 to 6.8, and that of Ta on the yellow color produced in· a solution which ·is. nearly 3 N H.2SO 4 and contains a little 

sulfite.; Bi, Sb, Fe, and Ti interfere. As little as 0.4 gamma of: Nb ·per ml 

. · 1 . , or. 50 gammas of Ta per rill can be determined. · 

96 Grube, G., and Grube, Hans L., 'i938, Electrochemistry of columbium: 

1 •• ~,. ;_ ,Zeitschr .. Elektroc;hemie; :Jland, 44, p. 711-780; cf. Chern. Abs., v. 

:. - . • -.~ ~3,. p. 20434, .. 
NIOBIUM AND TANTALUM, JANUARY 1935'-'-JUNE, 19-53 25 

An apparatus is described and illustrated which provides for electrolysis, .potential measurement, and titration with KMn04 in an atmosphere of hydrogen .. 

97 Gul'dina, E, 1., and others; 1940, Analysis of ferrocolumbium: Zavodskaya lab., tom _9, 500-507; cf. Chern. Abs., v. 34, p. _72123. 

On the basis of literature and experimental data, procedures are 

descrjbed for the analysis of Fe-Nb, including .the determination of Nb, 

Ta, Ti, Sn, Al, and Si. Final determination is as the oxides. 

98 Hagiwara, Hisato, 1948, Application of liqui4. amalg~ms. to the volumetric determination of columbium: Chern. Soc. Japan Jour., 

P~re Chemistry sec., v; 69, p. 129-133; cf. Chern. Abs., v. 44, p, 

9299i. 

99 Hahn, R. B., 1950, Tantalum phosphate; a new compound: ORNL-841; 

cf. Nuclear Sci. Abs., v. 5; p. 155 (no. 963), 1951. · 

Procedure for preparation,. composition data,. and X-ray data on 

TaOP04• 

100 Hahn, R. B., and Burros, C. L.; 1951, The determination of radioniobium in the presence of soluble orthophosphates: ORNL-831, 

cf. Nucle~r Sci. Abs., v. 5; p. 537 (no. 3362), i9·51. · 

' . 101 Haissinsky, M., and Jeng-Tsong, Yang, 1950, On the stability of certain 

organic complexes containing elements of the fourth and fifth 

groups of the periodic chart; [Pt.] ·2-:0xalates, ci_trates, and tartrates of Cb, Ta, and Pa: Anal. Chim. Acta, v. 4, p. 328-331 

[French]; cf. Nuclear Sci. 'Abs. v~ 4, p. 898 (n~. 6089). 

The preparation of hydroxides and complexes of Nb, Ta, and Pa, 

their decomposition by alkalies, and the·. pH_ measurements were made 

according to. methods previously used 'for Ti, .Zr, and 'Th compounds 

(Anal. Chim. Acta, v. 3, p. 422, 1949). The resistance to hydrolysis 

of the complexes of Nb and .Ta decreases in the. order oxalate > citrate 

> tartrate. In the case of oxalates, it is Nb > Ta; in that ·of the 

citrates it is Nb < Ta. . . 

102 Harpham, E~ W., 1946, Chemical determination of tantalum and 

columbium in tungsten-bearing heat-resisting steels: Metallurgia, 

v. 33, p. 245-247; cf. Chern. A,bs., v. 31, p. 73644; v. 40,. p. 33631. 

First dete~mine Nb and -Ta a·s Nb20 5 : + Ta20 5• The Ta 'and Nb 

can be separated by the' fractional tannin procedure as· described by 

Schoeller (Chern .. Abs;,, v. 31, p. 7364) ... 

103 ·Hartmann, H.·, and Massing, W ., 1951,-·Electrolysis in phosphate melts; 

· [Pt.] 4..:._Electrolysi's of oxides of vanadium, niobium, and tantalum 

in phosphate melts: Zeitschr. anorg. allg. Chemie, Band 266, p. 

· ,8-104; cf. Chern. Abs., v.-31, 83848, v. ,46,. p. 3426e.: 

104 Harvey, C. E., 1946, A method of semiqu~titative spectrographic analy-

. sis: Optical Soc.· America Jour., v. '36, p. 719. · , .. . . : . ' ' . ' 

, . Jt js based on a. direct-current arc. me.thod,. whereby .a weighed 

sample is completely arced, and selected line-to-backgr~mnd -ratios are 
26 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

evaluated densitometrically and the ratios multiplied by sensitivity 

factors for particular spectrum lines in a particular matrix. 

105 Hayashi, Shigehiko, 1949, Analysis of niobium and tantalum, [Pt;] !-

Separation of tantalum from niobium with tannin and cinchonine: 

Chern. Soc. Japan Jour., Pure Chemistry Sec., v. 70, p. 376-379; 

cf. Chern. Abs., v. 45, p. 2818a, 1951. 

At pH 1.6 all Ta is precipitated with tannin and cinchonine. 

106 --- 1950, Analysis of niobium and tantalum; [Pt.] 4-Ignition 

temperatures of the tannin complexes of niobium and tantalum; 

Chern. Soc. Japan Jour., Pure Chemistry Sec., v. 71, p. 17-18; 

cf. Chern. Abs. v. 45, p. 2818b, 5063c, 1951. 

Optimum temperature for Nb over 532° C and for 'Ta over 424 o C. 

107 Hayashi, Shigehiko, and Katsura, Tetsuo, 1949, Analysis of niobium 

and tantalum; [Pt.] 2-Separation with tannin and strychnine: 

Chern. Soc. Japan Jour., Pure Chemistry Section, v. 70, p. 435-437; 

cf. Chern. Abs., v. 45, p. 2818a, 1951. 

Tantalum is precipitated in presence of niobium. 

108 --- 1949, Analysis of niobium and tantalum; [Pt.] 3-Influence of 

brucine, antipyrine, aminopyrine, and urotropine .on the pH of 

formation of tannin complex; separation of tantalum from niobium 

with tannin and brucine: Chern. Soc. Japan Jour., Pure Chemistry 

Sec., v. 70, p. 437-439. 

Mixture of brucine and tannin is the best precipitating agent for 

the separation of Ta and Nb; Ta precipitates. 

109 Haywood, F. W., 1942, Some modern methods of metallurgical analysis: 

Metallurgia, v. 26, p. 117-120, cf. Chern. Abs., v. 36, p. 64329. 

Spectroscopic determination methods are described for Mn, Cr, Ni, 

V, Cu, Ti, Mo, P, Mg, W, Sb, Si, Nb, Ta, and Fe. 

110 Hecht, H., Jander, G., and Schlapmann, H., 1947, The action of thionyl 

chloride on oxides: Zeitschr. anorg. Chemie, Band 254, p. 255-264; 

cf. Chern. Abs., v. 43, p. 2886a. 

Metal oxide + SOC12 --+ metal chloride + S02• The following 

oxides can be treated: Ca, Ga, In, Ta, Tl, B, AI, Y, La, Nd, Pr, Ti, Zr, 

Th, Si, Ge, Zn, V, Nb, Ta, P, Mo, W, and U. 

111 Herman, P., 1948, Spectrographic determination of columbium and 

tantalum: Spectrochim. Acta, v. 3, p. 389-396 [French]; cf. 

Nuclear Sci. Abs., v. 2, p. 272 (no. 1222); Chern. Abs., v. 43, p. 

2543g. 

Determination is of 1 to 99 percent Nb or Ta in presence of Ti and W. 

112 Herman, P., and Gastellier, S., 19'46, Rapid determination of th<il 

tantalum and columbium in columbite: Service geol. Congo Belge et 

Ruanda-Urundi Bull., v. 2, p. 73-84; cf. Chern. Abs., v. 33, p. 

91868; v. 42, p. 2543b. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 27 

Analyses were made by a combination of the solution and separation 

methods of Schoeller and Powell, and the colorimetric determination 

of Nb and H20 2• 

113 Hillebrand, W. F., and Lundell, G. E. F., 1929, Applied inorganic 

analysis: New York, John Wiley and Sons, chap. 38, p. 463. 

Collected information about Nb and Ta-general considerations, 

attack of earth-acid minerals, methods of separation, and methods of 

determination. 

114 Hilliard, J. W. (Assigned to the American Steel and Wire Co. of N.J.), 

1949, Columbium in iron and steel: U. S. patent 2,482,850, September 27, 1949; cf. Chern. Abs., v. 44, p. 490d. 

Nb is determined qualitatively and quantitatively in Fe and its 

alloys. Nb weighed as Nb2 0 5 • 

115 Hiskey, C. F., Newman, L., and Atkinson, R. H., 1952, Analytical 

chemistry of niobium and tantalum-Atmospheric chlorination of 

hydrolyzed oxide precipitates: Anal. Chemistry, v. 24, p. 19'88-1991. 

The atmosphere chlorination of earth oxide mixt.ures by octachloropropane was investigated with the object of incorporating the reaction 

into an analytical scheme. Method adequate. 

116 Hiskey, C. F., and Batik, A. L., 1953, Analytical chemistry ofniobium 

and tantalum-Separation of iron and manganese from the earth 

acids: Anal. Chemistry, v. 25, p. 823-825. 

Method involves a precipitation of the earth oxides while retaining 

the Fe and Mn in solution with ethylenediaminetetraacetic acid. 

117 Holt, M. L., 1935, 'The electrodeposition of tantalum: Zeitschr. Elektrochemie, v. 41, p. 303-304; cf. Chern. Abs., v. 29, 53575. 

An attempt to repeat the experiment (Chern. Abs., v. 28, p. 49858) 

on the deposition of Ta from aqueous solution was unsuccessful. 

Cathodi~ deposits of Pt from the Pt anode dissolved during electrolysis 

were obtaine<!_, but no Ta. 

118 Hopkins, B. S., 1940, Columbium and tantalum; Chap. 15 in Chapters 

in the chemistry of the less familiar elements, v. 2: Champaign 

Ill., Stipes Publishing Co. 

History, occurrence, extraction, separation, metallurgy, compounds, 

determination. 

119 Huffman, E. H., and Iddings, G. M., 1952, Anion exchange of niobium 

in 7.0-molar hydrochloric acid: UCRL-1777, cf. Nuclear Sci. Abs., 

v. 6, p. 49'6 (no. 4014); Am. Chern. Soc. Jour., v. 74, p. 4714. 

In a recent report (Brown and Rieman, 1952, Am. Chern. Soc. 

Jour., v. 74, p. 1278) that elution of Ti from a cation-exchange resin 

With citrate solution resulted in broad elution bands with several peaks, 

this behavior was attributed to partial separation of Ti isotopes. The 

present single-nuclide study on the anion exchange of carrier-free Nb95 

resulted in elution curves of similar behavior and also not exactly 
28 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

reproducible. This departure from the expected type of elution band 

can probably be· attributed to the slow establishment of equilibrium 

among various ionic species that are present. 

120 Huffman, E. H., Iddings, G. M., and Libby, R. C., 1951, Anion exchange of zirconium, hafnium, niobium, and tantalum in hydrochloric acid solutions: Am. Chern. Soc. Jour., v. 73, 4474-4475; 

cf. Chern. Abs., v. 45, p. 7908h; v. 46, p. 1330c. 

Zr95 and Nb95 in 1 cc 6 to 7 M hydrochloric acid were separated by 

passing through a Dowex-2 column, 8 em in length and 3 mm in 

inside diameter, and washing with 3 cc acid. The elutant and wash 

contain the Zr. The Nb is then washed from the column with about 

4 cc of 1.5 to 4.0 M hydrochloric acid. 

121 Hume, D. N., 1951, Removal of zirconium and niobium from Amberlite resin adsorbent, in Coryell, C. D., and Sugarman, Nathan, eds., 

Radio-chemical studies--The fission products, Book 3 (Natl. Nuclear Energy Ser., Div. 4, v. 9): New York, Atomic Energy Comm. 

-McGraw-Hill Book Co., p. 1521-1522; cf. Chern Abs., v. 46, p. 

6546c. 

Hydrogen fluoride removes Zr and Nb activities adsorbed on Amberlite resin. 

122 Indichenko, L. N., 1948, Spectral analysis of iron and manganese ores: 

Akad. nauk SSSR Doklady, tom 59, p. 1157-1159; cf. Chern. Abs. 

v. 42, p. 7112e. 

Description of techniques employed in the spectrographic analysis 

of the ores, stressing Nb, Zr, and Ni. 

123 Jaboulay, B. E., 1948, Determination of tantalum and columbium in 

ferrotantalum, ferrocolumbium, and steel: Rev. metallurgie, v. 45, 

p. 434-347; cf. Chern. Abs., v. 43 p. 2119b. 

Method described is to precipitate and weigh combined Ta2 0 5 and 

Cb20 5 ; precipitate T·a20 5 in H20 2 • H2S04 solution; reprecipitate Cb20 5 

from solution by boiling filtrate with H2S04 and Na2S03 ; wash precipitate with water, calcine, and weigh. 

124 Jean, M., 1950, Bibliographical summary of chemical analyses of metallurgical products: Chimie anal., v. 32, p. 133-138, 162-167, 179-184, 

213-217. 

125 Jeffries, Z., 1941, Rare metals and minerals: Mining and Metallurgy, 

v. 22, p. 82-85; cf. Chern. Abs., v. 34, p. 27493; v. 35, p. 35747, 

A review of developments in 1940 covering Ba, Be, Ca, Co, Li, Pt 

group, Po, Ra, Se, Ta, W, U, V, and Zr. 

"26 Jeng-Tsopg, Yang, 1950, The separation of protactinium from Ta 

by fon exchange: A cad. sci. [Paris] Comptes rend us, tome 231, 

p. 1059-1601 [French]; cf. Nuclear Sci. Abs., v. 5, p. 29'2 (no. 

1826)' 1951. 

In a plastic column filled with the anion-exchange resin Amberlite 

IR-4B and an eluant of 6.5 N HF, which are brought to a pH of 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 29 

approximately 3 with concentrated NH4 0H, more than 90 percent of 

the Pa separates from Ta in a single operation. The Pa is eluted 

after the 'Ta. 

127 Johnson, C. M., 1946, Determination of tungsten and columbium in 

stainless steel: Iron Age, v. 157, no. 15, p. 66-68, cf. Chern. Abs., 

v. 40, p. 33636. 

A detailed procedure using known methods or modifications is given. 

The Ti is determined colorimetrically with hydroquinone. Color due to 

W and Nb fades. 

128 Johnson, Charles M., 1946, Colorimetric determination of tungsten, 

titanium, and columbium: Iron Age, v. 157, no. 14, p. 66-69, 

cf. Chern. Abs., v. 40, p. 33641. 

Determination is made by the hydroquinone photometric method, 

which gives no color for Ta and V. 

129 Karyakin, Yu. V., and Telezhnikova, P. M., 1946, Test for columbium 

and tantalum with. polyphenols: Zhur. priklad. khimii, tom 19, 

p. 435-439; cf. Chern. Abs., v. 41, p. 1170i. 

Studies with 22 polyphenols and ions of Nb, Ta, and Ti showed 

that only pyrogallol, pyrocatechol, and gallic acid produce yellow 

colors; no other reagent was effective, in contradiction to numerous 

references cited. The colors were produced as follows: Nb gave the 

color only in alkaline solution, and Ta gave color only in acid solution, 

whereas Ti gave the color in either acid or alkaline solutions. 

130 Kiba, Toshiyaso, and Ikeda, Tadasi, 1939, Studies of gravimetric 

analysis by means of the thermo balance; [Pt.] 21-Determination 

of calcium, lead, and thorium as picrolonate and of phosphorus, pal· 

ladium, columbium, zirconium, gold, beryllium, tantalum, and 

silicon by the oxine method: .Chern. Soc. Japan Jour., v. 60, p. 911-

914; cf. Chern. Abs., v. 28, 43319; v. 34, p. 15855. 

The proper temperatures for drying as determined by the thermobalance are: Th picrolonate, less than 35 o C; anhydride, 160°-180° C; 

Nb20 5 oxine, 100°-130° C; Zr oxinate, 115°-150° C; and Ta20 5, more 

than 450° C. 

131 Klimenko, N. G., and Syrokomski, V. S., 1947, Determination of the 

pH of the beginning of precipitation of niobium and tantalum: 

Zavodskaya lab., tom 13, p. 1029-1034; cf. Chern. Abs., v. 43, 

p. 4~83d. 

132 Klinger, P., 1939, Columbium and tantalum; [Pt.] !-Introduction: 

Tech. Mitt. Krupp, Forschungsber., Band 2, p. 171-173; cf. Chern. 

Abs., v. 34, p. 403, 

Methods of separation of Nb and Ta are critically discussed. 

133 Klinger, P., and Koch, W., 1939, Photometric determination and separation of columbium, tantalum, and titanium in steel and ferroalloys: 

Archiv Eisenhiittenw., Band 13, p. 127-134; cf. Chern. Abs., v. 33, 

p. 9186s. 
30 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

The known methods for separating and determining Nb, Ta, and Ti 

are reviewed. Procedure recommended based on the coloration of Ti and 

Nb with H2 0 2 ; the Ti coloration is strongest in dilute H 2S04 , that 

of Nb in concentrated H2 S04 • By using differences in the intensity of 

coloration in different acid concentrations a method was developed for 

determining both Nb and Ti in the presence of HTa03• For the determination of Ti the color reaction with chromotropic acid is recommended. 

Procedures are described in detail. 

134 --- 1939, Photometric determination and separation of columbium, 

tantalum, and titanium in steel and iron alloys: Tech. Mitt. Krupp, 

Forschungsber., Band 2, p. 179-185, cf. Chern. Abs., v. 33, p. 

91868; v. 34, p. 406. 

135 Klinger, P., Stengel, E., and Wirtz, H., 1941, Analysis of tantalum 

metal: Metall u. Erz, v. 38, p. 124-127; cf. Chern. Abs., v. 35, p. 

54098, 

The Ta is precipitated with hydrogen peroxide (after solution in 

HN03 , Hl,i', and K2S2 0 7 ), ignited, and weighed as Ta2 0 5 ; Nb is determined colorimetrically with hydrogen peroxide in 100 percent H 2S04 ; 

and 'Ti is determined by means of color reaction of Ti4+ with chromotropic acid. 

136 Klinkenberg, P. F. A., and Van Den Berg, G. J., 1950, Structure 

and Zeeman effect in the spectrum of the tantalum atom Ta I: 

Physica; v. 16, p. 861-889;; cf. Nuclear Sci. Abs., v. 5, p. 441 

(no. 2747); Chern. Abs., v. 45, p 7868i, 1951. 

137 Knowles, H. B., and Lundell, G. E. F., 1949, Volumetric determination 

of columbium: Natl. Bur. Standards Jour. Research, v. 42, p. 

405-408; cf. Chern. Abs., v. 44, p. 7710d. 

The determination of Nb is based on reduction to Nb3+ with amalgamated Zn and reoxidation ·to Nb5+ with KMnO 4 , using ferroin as 

the indicator. 

138 Kohn, Andre, 1953, A radioactive technique for determination of tantalum in the ferroniobiums and niobium minerals: Acad. sci. [Paris] 

Comptes rendus, tome 236, p. 1419-1421 [French]; cf. Nuclear 

Sci. Abs., v. 7, p. 411 (no. 3368). 

The method permits the determination of Ta without any chemical 

separation of Ta and Nb. It consists in measuring the activity of 

samples and standards irradiated together in a slow neutron flux. 

The tests undertaken have permitted the exact determination of the 

corresponding importance of the diverse causes of error. The content of 

'Ta can be known to less than 5 percent. 

139 Komarovskii, A. S., and Shapiro, M. I., 1938, Sensitive, catalytic test 

for columbium and tantalum: Mikrochimica Acta, Band 3, p. 

144-146, cf. Chern. Abs., v. 32, p. 53296. 

The test depends, as Feigl has shown, upon the fact that substances. 

capable of forming per-acids cause Na2 S2 0 3 to be oxidized to S04

2-

instead of S, which usually forms. 0.2 y Nb or 0.4 y Ta suffices to 

give the test. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953. 31 

140 Komovskii, G. F., and Golovchiner, Ya., 1942, An application of ionic 

Roentgen tubes for quantitative spectrographic analysis: Zhur. 

teckhn. fiziki, tom 12, p. 579-586; cf. Chern. Abs., v. 37, p. 22643, 

43019, 

Quantitative spectrographic analyses were made of artificial mixtures 

and minerals for Ta, W, Nb, Mo, Zr, Hf, Th, U, Ph, Co, and Ni by 

using a somewhat modified Roentgen tube. 

141 Krasilshchikov, B. S., and Popova, N. M., 1945, Determination of 

niobium in steel: Zavodskaya lab., tom 11, p. 512; cf. Analyst, v. 

73, p. 176, 1948. 

A determination of Nb and Ta as combined oxides is followed by a 

colorimetric determination of Ta with pyrogallol. 

142 Kraus, K. A., and Moore, G. E., 1949, Separation of columbium and 

tantalum with anion-exchange resins: Am. Chern. Soc. Jour., v. 

71, p. 3855. 

143 --- 1950, 4-nion exchange studies; [Pt.] !-Separation of zirconium 

and niobium in HCl• HF mixtures: ORNL--661; also Am. Chern. 

Soc. Jour., v. 73, p. 9-13; 1951; cf. Nuclear Sci. Abs., v. 4, p. 648 

(no. 4241), 19'50. 

Study of the behavior of Zr4+ and Nb5+ on the anion-exchange resin 

Dowex-1 in a number of HF • HCl mixtures. Separation of the two 

elements is excellent under a number of conditions. 

144 --- 1950, Anion exchange studies; [Pt.] 2-Tantalum in some 

HF•HCl mixtures: ORNL--661; also Am. Chern. Soc. Jour., v. 

73, p. 13-17, 1951; cf. Nuclear Sci. Abs., v. 4, p. 571 (no. 3713), 

1950. 

The ion-exchange behavior of Tawas studied for a number HF • HCl 

mixtures. It was found to adsorb very strongly under most conditions, 

even in 9 M hydrochloric acid. 

145 --- 1950, Anion-exchange studies; [Pt.] 3-Protactinium in some 

HCI• HF mixtures; separation of niobium, tantalum, and protactinium: ORNL--673; also Am. Chern. Soc. Jour., v. 73, p. 2900-

2905; cf. Nuclear Sci. Abs., v. 5, p. 159 (no. 990). 

146 Krasilschchikov, B. S., and Popova, N .. M., 1945, Determination of 

columbium in steel: Zavodskaya lab., tom 11, p. 512-515; cf. Chern. 

Abs., v. 40, p. 24095. 

Determine Nb20 5 + Ta20 5 ; fuse precipitate with KHS04 ; dissolve 

the melt in (NH4 ) 2C2 0 4 solution; and determine theTa colorimetrically 

with pyrogallol and the Nb by difference. 

147 Krishnaswami, K. R., and Murthi, D. Suryanarayana, 1935, Studies 

in tantalum and columbium: Indian Inst. Sci. Jour., v. 18A, p. 69-

73; cf. Chern. Abs., v. 21, p. 2624; v. 29, p. 78604. 

The optimum conditions are given for a proposed method. Ta and 

Nb are determined by heating the mixed pentoxides in a stream of 

hydrogen. The Nb20 5 is reduced to Nh0 2 ; the Ta20 5 is unaffected. 
32 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Authors advise heating for 1 hour at 800° C and cooling in the H2 

·stream. 

148 Krivoshlykov, N. F., 1939, Colorimetric determination of columbium 

and tantalum: Leningrad. krasnoznamenn. kh~m.-tekhnol. inst. 

Trudy, no. 7, p. 103-122; cf. Khim. referat. zhur., v. 2, no. 5, p. 

59-60, 1939; Chern. Abs., v. 34, p. 27293. 

The method is based on the color produced by Nb and Ta compounds 

with pyrogallol in acid and alkaline solutions; 0.05 mg of Nb20 5 and 

o:05-0.07 mg of Ta2 0 5 in 1 cc of solution can be detected. Titanium 

is determined with hydrogen peroxide. 

149 Krivoshlykov, N. F., and Platonov, M. S., 1937, Colorimetric determination of columbium and tantalum: Zhur. priklad. khimii, tom 1, 

p. 184-191 [German p. 191]; cf. Chern. Abs., v. ·31, p. 49213. 

Niobium gives a stable yellow color with pyrogallol in the presence 

of Na2S03 in alkaline solution and no color is an acid. solution, whereas 

Ta gives the same color only in acid solution. Titanium gives the same 

color with pyrogallol as Nb. ( NH2 ) 2 CrO 4 solution· ( 5 g per 250 ml of 

water) can be used as a standard instead of a standard solution of 

Nb and Ta. · 

150 Kroll, W. J., and Bacon, F. E. (to Electro Metallurgical Co.), 1948, 

Separation of columbium and tantalum oxides: U. S. patent 

2,443,254, June 15, 1948; cf. Chern. Abs., v. 42, p. 6500e. 

The NbC15 is separated from the residue by distillation and the 

cycle repeated. NbCl5 and Nb20 5 are produced according to the reaction, 5Nb2 0 4 + 5Cl2 -+ 2NbC15 + 4Nb20 5 after the Nb2 0 5 is 

selectively reduced to Nb2 0 4 by dry N2-free H 2 at 900° C. The H2 is 

then replaced by Cl2 and the temperature reduced to 400° - 600° C. 

151 Kuznetsov, V. I., 1941, Color reactions for thorium, uranium, and 

other elements: Acad. sci. U. R. S. S. Comptes rendus, v. 31, p. 

898-900 [English]; cf. Chern. Abs., v. 37, p. 8452. 

A very good study of the reaction of the following reagents with 

the ra're earths Th, U, Ti, Zr, Sn,. Nb, and Ta, in neutral or slightly 

acid· solution: 2-( o-arsonophenylazo) -p-cresol; 1-( o-arsonophenylazo)-

2-naphthol-3,6-disulfonic acid; 1-( o-arsonophenylazo) -2-naphthol-6,8-disulfonic acid; 3-( o-arsonophenylazo)- 4,5-dihydroxy-2,7-naphthalenedisulfonic acid. -

152 ---1945, Increase of sharpness of color tests with organic reagents: 

Akad. nauk SSSR Doklady, tom 50, p. 233-239; cf. Chern. Abs., v. 

43, p. 4174g. 

The color formation in organic reagents is reviewed on the basis of 

the internal ionization in molecules containing distinct dipole character; 

.the metals Ti, ·u, Zr, Mo, Nb, W, Bi, 'Th, Sb, Th, Ag, .Pb, and Cu are 

considered. 

153 ---·and Vasyunina, N. A., 1940; The reactions of aminobenzenearsonic ·acids with 2-furaldehyde: Zhur. obshchey khimii; tom 10, 

p. 1'203-1209; cf. Chern. Abs., v. 35, p. 28692• 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 33 

The reaction can be. used as a color test for Sn4+, Ti, Zr, Hf, Nb, Ta, 

Th, Sb, Bi, C:r8+, Mo, U, and W ions, in solutions stronger than 0.1 

mg metal per mi. 

164 Kvalheim, A., Rutlin, S., and Aarnseth, K. A., 1952, "Schulze-method" 

for the chemical determination of niobium in soevite rock: Tidsskr. 

Kjemi, Bergvesen o. Metallurgi, v. 12, p. 93-96, cf. British Abs., 

v. 1C, no. 24, 1953; Chern. Abs., v. 47, p. 2633h. 

This chemical analysis is based on precipitation .of Ta and Nb as 

tannate, weighing as oxides after ashing, and deduction of Ta, which 

is determined colorimetrically. When carried out with care, it yields 

fairly good results. The Nb figures are usually approximately 7 percent 

(relatively) low. This is presumably due to a slight solubility of Nb 

mineral in HN03 (in the pretreatment process), and to the incomplete 

decomposition of Nb minerals by H2SO4 (to dissolve the Nb), because 

of unexposed particles. The average content of the soevite rock is 

approximately 0.2 percent of Nb2 0 5• The residues, precipitate, filtrates, 

etc., from the chemical analysis were controlled by spectrographic 

analysis. 

155 Lauw-Zecha, A. B. H., Lord, S. S., and Hume, D. N., 1952, Colorimetric determination of niobium using thiocyanate: Anal. Chemistry, v. 24, p. 1169-1173. 

Reaction between CNSl- and Nb is basis for rapid spectrophotometric determination of microgram amounts of Nb. The sample in 

hydrochloric acid is treated with SnCl2 and KCNS; the resulti'ng 

yellow complex is ether-extracted and the absorbancy measured at 

385 m mu. Beer's Law holds for 1 to 65 micrograms per 25 ml of 

ether extract. 

156 Leddicotte, G. W., and Moore, F. L., 1952, A new solvent extraction 

method for the separation of niobium and tantalum: Am. Chern. 

Soc. Jour., v. 74, p. 1618; cf. Chern. Abs., v. 47, p. 5300/. 

Niobium can be extracted quantitatively from strong hydrochloric 

acid with a solution of methyldioctylamine in xylene. Under these 

conditions extraction of Ta appears to be negligible. The Nb may then 

be "stripped" from the organic phase with HN03, H2S04, or dilute 

hydrochloric acid. Authors suggest approximately 8 M hydrochloric 

acid concentration for the separation, using equal volume of a 5 

percent solution of methyldioctylamine in xylene. 

157 Lokka, Lauri, 1950, Photometric .determination of Nb20 5 in mixed 

oxides Nb2 0 5 + Ta20 5 : Comm. geol. Finlande Bull., no. 149, 

p. 39. . 

On the chemistry of the radioactive minerals of Finland. 

158 Lomonosova, L. S., 1950, Spectrographic determination of titanium 

and niobium in powdered ~antalum: Izv. Akad. nauk SSSR, Ser. 

· fiz., tom 14, p. 693-695. 

159 Long, J. V. P., 1950, The analysis of mixtures containing Ta by measurement of radioactivity produced by neutron irradiation: CRLAE-60; Analyst, v. 76, p. 644-646, 1951; cf. Nuclear Sci. Abs., 

v. 5, p. 288 (no. 1801), 1951. 
84 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CllEMISTRY 

A neutron-activitation method is described for the determination 

of Ta in mixtures also containing Nb, Zr, Fe, Sn, Ti, and· Si. The 

method depends on the pile irradiation of the sample, followed after 

4 days by measurement of the filtered gamma-ray activity. An accuracy 

of about + 2 percent can be achieved. 

160 Mackay, R. A., 1951, The detection of columbite by ultraviolet light: 

Inst. Mining and Metallurgy Bull., v. 530, p. 129-131, cf. Chern. 

Abs., v. 45, p. 3296h, 1951. 

Flux contained 2 percent of Na2S04 , 5 percent of NaF, 46.5 percent 

of Na2C03, and 46.5 percent of K2C03 by weight. A nickel dish was 

used. 

161 Martell, A. E., and Calvin, M., 1952, Chemistry of the metal chelate 

compounds: New York, N. Y., Prentice-Hall. 

A useful collection and formulation of the data existing at present 

about chelate compounds. 

162 Martini, Ardoino, 1941, Course in qualitative microanalysis: Univ. Nac. 

Litoral Rosario, Inst. Inv. Microquim. Pub., v. 5, no. 5, p. 121-144, 

cf. Chern. Abs., v. 36, p. 61088; v. 40, p. 53512. 

Standard tests for C, Ti, Zr, 'Th, Bi, Sb, As, Ta, Nb, V, and U are 

described and discussed. 

163 Maurer, W. C., (to Carnegie-Illinois Steel Co.) 1948, Determination 

of columbium carbide in stainless steel: U. S. patent 2,447,763, 

August 24, 1948; cf. Chern. Abs., v. 43, p. 522h. 

Insoluble Cb carbide is separated from soh1ble Cb by digestion with 

dilute H2S04 and determined gravimetrically as Nb2 0 5• 

164 Meimberg, E., 1913, Bestimmung der Tantalsaure und Niobsaure in 

Tantaliten, Columbiten, Yttrotantaliten, Fergusoniten, und colorimetrische Niobbestimmung: Zeitschr. angew. Chemie, v. 26, p. 83. 

Niobium, unlike Ta, is reduced to Nb3+ by various metals such as 

Zn and Sn in acid solution. Brown color obtained serves for a photometric determination. Method applied in determination of Nb in 

tantalite. Tantalite was dissolved in HF • HCl and the bulk of Ta 

separated as K fluotantalate. 

165 Mercer, R. A., and Williams, A. F., 1952, Inorganic chromatography 

on cellulose; [Pt.] 13-Determination of tantalum and niobium 

in low-grade phosphatic and siliceous ores; Chern. Soc. London, 

Jour., p. 3399-3403; cf. Chern. Abs., v. 46, p. 7470i; v. 47, p. 1537d. 

The chromatographic method is extended to ores containing less than 

0.1 percent Ta20 5 + Nb20 5• In the chromatographic procedures previously described, the sample is digested with HCl + NH4F and 

placed on a column of cellulose. Ta was extracted with methyl ethyl 

ketone which was saturated with water and the column was then 

equilibrated with methyl ethyl ketone containing 12.5 percent of 40-

percent HF by volume .. The procedure has given good results in determining 0.2 to 0.9 percent Ta20 5 and 0.28 to 1.03 percent Nb20 5• 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 35 

166 Meerson, G. A., Kats, G. A., and Khokhlova, A. V., 1940, Reduction of 

the oxides of metals of high melting points with calcium hydride: 

Zhur priklad. khimii, tom 13, p. 1770-1776 [French, p. 1776]; cf. 

Chern. Abs., v. 35, p. p. 47121. 

Ti02 , Nb20 5, V 20 5, and Ta20 5 were reduced with CaH2 in H2 at 

atmospheric pressure in electric furnaces. 

167 Melentyev, B. N., and Terekhovko, A. S., 19·40, The analysis of perovskite: Akad. nauk SSSR Trudy Kol'skaya baza, no. 5, p. 71-76; 

cf. Khim. referat. zhur., tom 4, no. 2, p. 60, 1941; Chern. Abs., v. 

37, p. 30193. 

Decomposition with H2SO4 ; citric acid used to prevent hydrolysis; 

Ti, Ta, and Nb precipitated with cupferron. 

168 Miller, C. Franklin, 1937, Tannic acid in analysis: Chemist Analyst, v. 

· 26, p .. 38-39, cf. Chern. Abs., v. 31, p. 57099. 

'The tests for Ti, Fe, Nb, Ta, Ag, Au, U, Hg, HV0 3, H2Mo04, as 

recommended by Schoeller and his coworkers, are reviewed. 

169 Miller, C. C., and Lowe, A. J., 1940, Qualitative semimicro analysis 

with reference to Noyes' and Bray's system-The tantalum and 

tungsten group: Chern. Soc. London Jour., p. 1258-1263; cf. Chern. 

Abs., v. 21, p. 3583; v. 31, p. 73644; v. 35, p. 7078. 

Application of methods proposed by Noyes and Bray followed the 

methods proposed by Schoeller. Very satisfactory results were reported. 

170 Milner, G. W. C., and Wood, A. J., 1952, The analysis of uraniumtantalum and uranium-niobium alloys: AERE C/R-895; 13 p.; cf. 

Nuclear Sci. Abs., v. 6, p. 617 (no. 5050). 

Satisfactory procedures are described for the analysis of uraniumtantalum and uranium-niobium alloys that contain up to 25 percent 

Ta and Nb, respectively. They are based on the separation of the Ta 

and Nb from U by extracting the fluorides of the former elements 

with methyl ethyl ketone. After the evaporation of t4e solvent from 

the combined organic extracts, the residue is ignited ( 800° C.) to yield 

the pentoxides. Absorptiometric procedures are included for the determination of trace amounts of unextracted 'Ta and Nb. 

171 Moir, J., 19'16, Analysis of niobium-tantalum minerals, with some 

new tests for niobium, tantalum, and titanium: Chern. News, v. 

113, p. 256. 

Thiocyanate reacts with Nb3+ in acid solution. The resulting solution 

has a yellow-orange color, the intensity of which is critically dependent 

on acid concentration (qualitative). Thymol also gives a color reaction 

(qualitative). 

172 More, Ch., 1943, Niobium or columbium: Metallurgia, v. 75, no. 12, 

p. 1-2; cf. Chern. Abs., v. 40, p. 56795. 

A review covering natural occurrence of niobium, its production, 

properties, and uses. 
36 ·SELECTED BIBLIOGRAPlllES OF ANALYTICAL CltEMISTRY 

173 Myers, R. H., 1943, A review of the literature on the chemistry and 

metallurgy of tantalum and columbium: Australasian Inst. Mining and Metallurgy Proc., no. 129, p. 55-79; cf. Chern. Abs., v. 

37, p. 66116. 

174 Nachtrieb, N. H., and Tobin, William J., 1951, Spectrochemical analysis of columbium and zirconium: AECD-3103; ANL-HDY-579. 

cf. Nuclear Sci. Abs., v. 5, p. 490 (no. 3056). 

175 Namoradze, Z. G., and Zvyagintsev, 0. Ye, 1939, Solubility of tantalum 

chloride and bromide in organic solvents: Zhur. priklad. khimii, 

tom 12, p. 603-608 [French p. 608]; cf. Chern. Abs., v. 33, p. 84755. 

Data are tabulated and plotted for solubility in CC14 , CS2, CHCl8, 

EtBr, PhN02, and H2NCH2CH2NH2• 

176 Novikov, V. A., 1939, Application of film reactions and of etching to 

the mineralogical analysis of deposits: Sov~tskaya geologiya, v. 9, 

no. 10-11, p. 116-120; cf. Chern. Abs., v. 35, p. 4069. 

Author finds that Mo and Ta-columbite ores can be distinguished 

from one another and from other ores by the characteristic color films 

appearing when they are treated with concentrated H2SO4 at about 

300° c. 

177 Oka, Y oshinaga, and Miyamoto, Masatoshi, 1948, Volumetric determination of columbium: Chern. Soc. Japan Jour., Pure Chemistry 

Sec., v. 69, p. 133-137, cf. Chern. Abs., v. 44, p. 9299'h. 

A method of ·determining Nb without use of a correction factor 

was developed. When Ti is present, less than 1 mg Nb20 5 could not 

be determined. In a mixture of the oxides Nb20 5 and Ta20 5, 2 mg 

Nb2 0 5 can be determined in the presence of 50 mg Ta2 0 5• 

178. --- 1949, Volumetric determination of Cb: Tohoku Univ., Research 

Inst. Sci. Repts., ser. A, v. 1, p. 115-119; cf. Chern. Abs., v. 44, 

p. 9299h, 10578e, 1950. 

Reduction with Zn amalgam is followed with a KHn04 titration. 

179 Osborn~ G. H., 1953, Bibliography of the analytical applications of ionexchange resins: Analyst, v. 78, p. 221-252. 

180 Oshman, V. A., 1946, The separation of columbium and tantalum from 

titanium: Zavodskaya lab., tom 12, p. 154-157; cf. Chern. Abs., v. 

40, p. 5660.8. 

Separate Nb and Ta from Ti by means of reduction with amalgam; 

determine Ti02 and Zr02 in aqueous phase (Ti by H20 2 and Zr by 

phosphate); subtract the sum of the Ti02 + Zr02 from the original 

weight of the precipitate of the impure earth oxides; and determine 

the percent content of the sum of the earth oxides by the usual 

method. 

181 Palilla, F. C., Adler, N., and Hisk~y, C. F., 1953, Analytical chemistry 

of niobium and tantalum-Simultaneous spectrophotometric determination of tantalum and niobium: Anal. Chemistry, v. 25, p. 

926--931. 
NIOBIUM AND TANTALUM, JANUARY 1935,--JUNE, 1953 · 87 

The peroxy complexes of groups IV to VII of transition elements, 

formed in concentrated H2SO4 media,- were investigated. for application to the analysis of niobia and tantala. mixtures. One result of this 

study was the discovery of a peroxy-tantalate· whose absorption spectrum had its peak at 285 m mu. Since the peroxy-niobate formed under 

identical conditions had its peak at 365 m mu,· it was pos~ible to develop 

a method for the simultaneous determination of Nb and Ta mixtures. 

This method has a precision of about 0.5 percent and is independent 

of Nb-Ta ratio. 

182 Pearson, J. G., 1936, Microanalysis; CPt.] 2~Tests for rare and common metals: Chern. Eng. Min. Rev., v. 28, p. 151-164; ·· cf. Chern. 

Abs., v. 30, p. 25174, 33545. 

This instalment includes microtests for Mn, Li, Th, Ta, Ni, T.i, W, 

Au, Ce, Co, As, Cu2+, Cu+, CH20, water, nitrates, and F.. · 

183 Pennington, M. E., 1896, KCNS as reagent in colorimetric determination of niobium: Am. Chern. Soc. Jour., v. 18, p. 51. 

Thiocyanate reacts with NbS+ in acid solution. The r~sulting solution has a yellow-orange color. A study of the analytical application 

of the method is pre~nted. 

184 Pfeiffer, P., Bottcher, H., Pratorius, W., and Kwan, Li Mou, 1936, 

Betainelike complex salts: Zeitschr. anorg. allg. Chemie, Band 

230, p. 97-111; cf. Chern. Abs., v. 31, p. 38089, 

185 Pigott, E. C., 1942, The chemical and physico-chemical analysis of iron 

and steel: Metallurgia, v. 26, p. 73-74; 113-116, and 145-147, 

Chern. Abs., v. 36, p. 61189. 

In this and some subsequent articles the author gives an exhaustive 

and descriptive bibliography of contributions to ferrous analysis 

published during the period ·1930-41. They reveal the developments 

in analytical methods which have become more direct and of wider 

application in meeting demands for speed combined with accuracy. 

Photometric, spectrographic, polarographic, and chemical determinations are given in this series of papers. 

186 --- 1942, Twelve years' progress; [Pt.]2-The determination of 

· single constituents: Metallurgia, v. 26, p. 31-33, · cf .. Chern. Abs., 

v. 36, p. 61188; v. 37, p. 8445. 

The determination of P, Se, Si, S, Ta, and Te as single constituents 

is considered. · 

187 --- 1942, Qualitative chemical tests for iron, steel, and foundry 

materials: Iron and Steel [London], v. 16, p. 196-199', 202; cf. 

Chern. Abs., v. 38, p. 17024, 1944. 

Tests are given for AI, As, B, C, Ce, Cr, Co, Cu, Fe, Ph, Mn, Mo, 

Ni, Nb, P, Se, Si, S, _Ta, Te, Sn, Ti, W, U, V, Zn, and Zr. 

188 Platonov, M. S., and Krivoshlykov, N. F., 1943, Detection and colorimetric determination of Cb and Ta: , V ses. konf. anal. khimii 

Trudy, tom 2, p. 359-370; cf. Chern, Abs., v. 39', p. 34924, 1945. 
38 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Sum of pentoxides is determined gravimetrically and one of the metals 

determined colorimetrically with pyrogallol. Color caused by Nb or Ti. 

189 Platonov, M. S., Krisoshylkov, N. F., and Maraka'yev, A. A., 1936, 

New qualitative reactions of columbium and tantalum: Zhur 

obshchey khimii, tom 6, p. 1815-1817; cf. Chern. Abs., v. 31, p. 

46149, 

New methods for the determination of small amounts of Nb and Ta 

in the presence of each other and of Ti consist in fusing the sample 

with KHSO 4 at 450° - 700° C and leaching the melt with a concentrated 

solution of (NH4 ) 2C20 4• The solution gives color reactions with resorcinol or pyrogallol in alkaline or acid solutions.. These methods are 

very sensitive. 

190 --·- 1938, New quantitative reactions of columbium and tantalum: 

Zhur. obshchey khimii, tom 8, p. 829; cf. Chern. Abs., v. 33, p. 

4973. 

Reactions of Nb and Ta with organic reagents are given. 

191 Poehlman, W. J., and Sarnowski, R. E., 1952, Spectrochemical determination of tantalum and niobium in 18 Cr-8 Ni stainless steel: 

Optical Soc. America Jour., v. 42, p. 489'--492; cf. Chern. Abs., v. 

46, p. 8570b; British Abs. v. 12C, p. 3936, 1952. 

A spectrographic method for determining Ta and Nb, covering the 

concentration ranges 0.01 - 0.40 percent and 0.30 - 1.25 percent, respectively, is described. Samples are excited by an alternating-current 

arc discharge from point to plane. A prism-type spectrograph is employed, and the resulting spectrograms are recorded on calibrated · 

emulsions. With the Fe matrix as an internal standard, photographic 

photometer readings and intensity ratio comparisons are made for the 

all.alytical line pairs 3311.16 'Ta against 3165.86 Fe, and 3299.61 Nb 

against 3165.01 Fe. Included in the discussion are referee analyses, 

comparisons, working curves, and standards. The analytical results of 

this method indicate adequate sensitivity, precision, accuracy, and 

range of analysis for this kind of material. 

192 Pokrovskaya, T. L., 1945, Analysis of cassiterite: Zavodskaya lab., tom 

11, p. 363-364; cf. Chern. Abs., v. 40, p. 33674. 

Complete details are given for determining Sn, Nb, Ta, Zr, Ti, Mg, 

Mn, Fe, W, and As in cassiterite by known methods. 

193 Popova, N. M., and Platonova, A. F., 1950, Determination of niobium 

carbide in steels: Zavodskaya lab., tom 16, p. 1182-1185; cf. 

Chern. Abs., v. 47, p. 3181a. 

Dissolve · the sample anodically by using an electrolyte containing 

N HCl, N KCl, and 1 percent H2S04 for Cr-Ni austenite steels and 

an electrolyte containing N KCl and 0.5 percent citric acid for lowalloy steels. Wash off the carbide precipitate with water and let 

settle; remove residues of carbide particles from the sample with 

filter paper, place in filter, and decant through the filter the water 

from settled carbides (precipitate no. 1). Wash the carbide residue 

with water and then with EtOH, dry in a stream of H2 for 1 hour at 
NIOBIUM ANI> TANTALUM, JANUARY 1935-JUNE, i953 39 

100° C on a water bath. and for 1 hour at 200° C on an oil bath, cool, 

and purge for 2 hours with N 2 • To 40 to 60 mg of dry precipitate add 

10 to 15 ml HF, boil for 30 minutes, dilute with cold water, and filter 

(precipitate no. 2). Evaporate the filtrate three times with 5-ml portions of concentrated H2SO4, separate Nb by hydrolysis with 3-percent 

HCl, fuse the precipitate with K2S2 0 7 , decompose in 100 ml of 5-

percent pyrogallol, add 10 ml of 25-percent NH4 0H to dissolve the 

precipitate, and filter. Wash to remove all coloration, acidify the 

filtrate with 40 ml of 6 N HCI, allow to stand for 1 to 2 hours at 70° 

to 80° C, filter, wash with warm water, calcine, and weigh as Nb20 5• 

Calcine precipitates numbers 1 and 2, fuse with K2S2 0 7, and determine 

Nb with pyrogallol as above. 

194 Portnov, A. I., 1948, Application of aromatic arsenic compounds in 

chemical analysis: Zhur. obshchey khimii, tom 18, p. 594-600; 

cf. Chern. Abs., v. 43, p. 57c. 

A study of insoluble metal salts of a number of aromatic arsonic 

acids. An English translation has been made by the U. S. Geological 

Survey and reported as TEIR-324. 

195 Portnov, 1\f. A., 1939, Automatic and electrometric methods of analysis: 

Gos. inst. priklad. khimii Sbornik statey 1919-39, p. 100-142; cf. 

Khim. referat. zhur., no. 3, p. 52-53, 1940; Chern. Abs., v. 36, p. 

22229. 

The paper describes methods of electrometric analysis and automatic 

production control. Niobium and Ta are determined polarographically. 

196 Powell, A. R., and Schoeller, W. R., 1925, A new method for the 

separation of tantalum from niobium: Analyst, v. 50, p. 485. 

Separation effected by the use of tannin. 

196a --- 1925, 'The detection and determination of tantalum in niobium 

compounds: Analyst, v. 50, p. 94. 

196b --- 1930, A new method for the separation of titanium from 

zirconium and hafnium: Analyst, v. 55, p. 605-612. 

A tannic acid method is described. 

197 --- and J ahn, C., 1935, Investigations into the analytical chemistry 

of tantalum, columbium and their mineral associates; [Pt.] 29-

The separation of W from Ti, Cb, Ta, and Zr: Analyst, v. 60, p. 

506-514; cf. Chern. Abs., v. 18, p. 950; v. 29', p. 7219. 

Zirconium can be separated from W by fusing with alkali carbonate 

and leaching the melt with water (Na2W04 ex~racted). The only procedure found satisfactory by authors for separating W from Ti, Nb. 

Ta, and Zr, consists in fusing mixed oxides with K2C03 and treating 

the aqueous extract of the melt with slightly ammoniacal 1\fgSO 4 solution containing NH4Cl; the earths are precipitated and K2W04 remains 

in sol uti on. 

198 Prede, A. F., 1934, Columbi:um: Redkie metally, v. 3, no. 6, p. 6-8; cf. 

Chern. Abs., v. 29, p. 32064. 
40 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

A review of the physical and chemical properties of Nb and its 

compo~nds, and m~thods of its recovery is provided. 

199. Prodinger, W., 1940, Organic reagents used in quantitative inorganic 

analysis: New York, Elsevier Publishing Co., 203 p. 

'This monograph correlates widely scattered material on brganic 

;reag_ents into a concise, usable form. 

201 Rankama, Kalervo, 1944, The geochemistry of tantalum: Comm. geol. 

·Finlande Bull., no. 133, p. 1-78; cf. Chern. Abs., v. 5, p. 3544; 

v. 32, p. 762; v .. 40, ·p. 11224. 

·Analyses for .Ta . by several methods are given for 237 mineral 

samples, 41 ore samples, 136 rocks, and 10 meteorites. The analyses 

include X-ray spectrographic method after chemical enrichment. Author 

.employed salicylic acid for enrichment of Nb and Ta in the phenyliirsonic ·acid precipitate ·containing Ti and Zr. 

202 --- 1948, The geochemistry of columbium: Acad. Sci. Fennicae 

Annales, ser. A. III. Geol-geog., no. 13, 57 p. [English]; cf. 

Chern. Abs., v. 44, p. 3855. 

203 Rasmussen, S. W. and Rodden, C. J., 19'50, Vanadium, niobium, and 

tantalum, in Rodden, C. J., ed., Analytical Chemistry of the Manhattan Proj. (Natl. Nuclear Energy Ser., Div. 8, 1. 1): New York, 

Atomic Energy Comm.-McGraw-Hill Book Co., p. 459-482; cf. 

Chern. Abs., v. 45, p. 1910g. 

Presentation of various analytical methods. 

204 Redmond, J. C., 1948, Rapid spectrographic analysis of cemented carbide 

compositions: Steel, v. 122, no. 26, p. 86-88; cf. Chern. Abs., v. 42, 

p. 5798d. 

Equipment, technique, and standards are described for the quantitative spectrographic analysis of Ti, Nb, Ta, Fe, Ni, W; Co, and Mo. 

Results· are within 3 to 10 percent of those obtained by chemical 

methods . 

. 205 Rogers,· B., 1948, Routine chemical methods for the chemical analysis 

of columbium-· and tantalum-bearing 18/8 steels·: Metallurgia, v. 

37, p. 326-330; cf. Chern. Abs., v. 42, p. 6265g. 

This is a discussion of the principles involved in the determination 

of Nb, ·Ta, and W, in steel, and the modifications required in Cunningham's procedure in the presence of W, Mo, and Ti. Includes 42 

references. 

206 Rohmer, R., 1941, Attack of rare earth minerals and the separation 

of columbium and tantalum: Acad. sci [Paris] Comptes rend us, 

tome 212, p. 614-616; cf. Chern. Abs., v. 36, p. 3645. 

207 

Minerals decomposed by fusion with KHS04 followed by solution in 

H2S04 + H20 2 ; Nb and Ta separated by fractional crystallization of 

double fluorides. · 

Rosenthaler, L., 1938, The composition of drug ash: Mikrochemie, v. 25, 

p. 5-8; ~f. Chern. Abs., v. 32, p. 93998; v. 33, p. 14429. 

Methods for detecting Sn, V, U, Ga, Mn, Nb, Ta, and B are described. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 41 

208 Ruff, 0., and 'Thomas, F., 1926, The effect of a carbon tetrachloride ·on 

columbium and tantalum pentoxides and a procedure for the 

analytical determination of columbium and tantalum: Zeitschr. 

anorg. allg. Chemie, Band 156, p. 213-225; cf. Chern. Abs., v. 21, 

p. 26245. 

Nb2 0 5 is easily converted to NbCl5 at 200°-225° C in an atmosphere 

of CC14 vapors, while Ta20 5 is unaffected. 

209 Sanderson, L., 1940, Tantalum: Canadian Min. Jour., v. 61, p. 803-804; 

cf. Chern. Abs., v. 35, p. 7143. 

The peculiar physical and chemical properties of Ta meet a great 

variety of uses. Sources, uses, and alloys are enumerated. 

210 Sandell, E. B., 1950, Colorimetric determination of traces of metals: 

2d ed., New York, Interscience Publishers, p. 291. 

Some methods of determination and separation are presented and 

discussed. 

211 Sato, lchiro, and Komatsu, Manryu, (to Nihon Elec. Co.) 1947, Tantalum metal from crude tantalic acid: Japan patent 175,161, Oct. 23, 

19'47; cf. Chern. Abs., v. 44, p. 5303/, 1950. 

212 Savchenko, G. S., and Tanana'yev, I. B., 1947, Investigation in the 

field of complex fluorides of Ta and Cb: Zhur. priklad. khimii, tom 

20, p. 385 [Russiap]; cf. NP-2191, July 1950; Nuclear Sci. Abs., 

v. 5, p. 292 (no. 1825), 1951. 

A procedure for the separation of Nb and 'Ta has been developed 

based on dissolving a mixture of the oxides in HF, formation of K 

double fluorides of both metals, and precipitation of K2 TaF 7 at 2 percent excess of acid. 

~13 Sawaya, Tsuguo, 1951, Analytical chemistry of complex fluoride compounds: Tohoku Univ. Technology Repts., v. 16, p. 17-65; cf. 

Chern. Abs., v. 46, p. 6989c. 

The use of complex F compounds in qualitative and quantitative 

analysis is reviewed and the results of numerous experiments are 

given. The methods studied include the detection of H3B03, H2Si03, 

Be, AI, Ti, Zr, Nb, Ta, and F, the titrimetric determination of H2Si03 , 

Ti, Zr, Nb, 'Ta, and F, and the colorimetric determination of H3B03 , 

AI, and Zr. In some cases, the different solubilities of complex F 

compounds can be used for separations. 

214 Schafer, Harold, 1948, The purification of columbium preparations: 

Zeitschr. N aturforsch. [Wiesbaden], Band 3-B, p. 376; cf. Chern. 

Abs., v. 43, p. 5688h. 

Titanium and Sn can be separated from Nb by heating the mixture 

of oxides with CC14 in a sealed tube. On cooling, the NbG15 and '.l'aC15 

crystallized; but TiCl4 and SnC14 , together with the phosgene ·produced, 

remained in solution. Preparations containing 30 percent Ti02 or 

Sn02 yield NbC15 that contains less than 0.01 percent Ti and no Sn. 
42 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

215 Schafer, Harold; Bayer, Lisel; and Lehmann, H.; 1952, Chemistry of 

the elements niobium and tantalum; [Pt:] 9-Equilibrium pressure 

of the decomposition of niobium tetrachloride: Zeitschr. anorg. allg. 

Chemie, Band 268, p. 268-278; cf. Chern. Abs:, v. 47, p. 3745a, 

5224g. 

216 Schafer, Harold; and Breil, Gunther; 1952, Chemistry of niobium and 

tantalum; [Pt.] 8-The system Nb20 5-Ta20 5-Nb02-Ta02-H20-H2 : 

Zeitschr. anorg. allg. Chemie, Band 267, p. 265-276; cf. Chern. 

Abs., v. 4 7, p. 37 45a. 

217 Schafer, Harold; and Pietruck, C.; 1951, Chemistry of niobium and 

tantalum; [Pt.] 2-The analytical determination of niobium and 

tantalum: Zeitschr. anorg. allg. Chemie, v. 264, p. 2-16 [German]; 

cf. Chern. Abs., v. 43, p. 5688h; v. 47, p. 3163e; Nuclear Sci. Abs., 

v. 5, p. 695 (no. 4386). 

Analysis of Nb and· Ta, separate or mixed, and in the presence of Sn 

and Ti, is described. A 0.5-g mixture of oxides is treated with 2 ml 

CC14 at 280° C in a sealed tube for 5-10 hours. TiC14 and SnC14 are then 

sublimed out under vacuum at 100° C. At 200° C the NbCl5 and TaC15 

are sublimed into a rubber-stoppered glass container, in which they 

can be weighed. The chlorides are dissolved in concentrated hydrochloric 

acid and evaporated to dryness, treated with water and evaporated 

twice, with concentrated NH3 solution and evaporated twice, and then 

'heated at 800°-900° C to constant weight as oxides. From the weights 

· of the pure chlorides and oxides the percentages of Nb and of Ta are calculated. Errors in the sum of the two oxides do not exceed 0.5 percent; 

for 1:1 mixtures of Nb. and Ta, they are no more than 1 percent for 

each. 

218 19'51, Chemistry of niobium and tantalum; [Pt.] 3-The preparative separation of niobium from tantalum, titanium, and 

tungsten by the oxalic acid method; Zeitschr. anorg. allg. Chemie, 

v. 264, p. 106-119; cf. Chern. Abs., v. 47, p. 3163g. 

'The Nb-Ta acid precipitate, with ratio of Ta20 5/Nb2 0 5 of 1,4 or less, 

is' treated with a solution of 3 to 10 g H 2C2 0 4 • H 20 dissolved in 100 

· ml 2 N hydrochloric acid. After 7 hours at 60° C from a starting sample 

in which the Nb20 5-Ta2 0 5 mixture contains 91 percent Nb20 5, the 

solution formed by 5 g H 2C20 4 • H 20 in 100 ml 2 N hydrochloric acid 

gives an oxide which is 99 percent Nb20 5 ; the oxide from the insoluble 

residue is 75 percent Nb2 0 5 • If the treatment is repeated on the 

soluble portion, the Ta20 5 in the dissolved part is 0.3 percent or less. 

For samples with a higher initial ratio of Ta, a different preliminary 

separation is worthwhile. From all tests on acid precipitates prepared 

in' a number of ways and aged ,various times, the values of percentage 

of Nb20 5 in the oxalic acid solution versus percentage of Nb20 5 in the 

residue fall near one or the other of two straight lines, the one line 

·breaking into the other at about 75 percent of Nb20 5 in residue. Two 

solid phases, one a tantalic acid which can hold Nb2 0 5 to about 75 

percent, the other a niobic acid holding Ta20 5 to about 25 percent, are 

indicated. If the initial acid precipitate contains Ti02, W03, and Sn02, 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 43 

the oxalic acid extraction removes Sn with the Nb but leaves the Ti 

and W largely in the residue. 

219 Schafer, Harold; Goser, Camill; and Bayer, Lisel; 1951, Chemistry 

of niobium and tantalum; [Pt.] 4-Niobium tetrachloride and its 

decomposition to the trichloride and the pentachloride: Zeitschr. 

anorg. allg. Chemie, v. 264-265, p. 258-272; cf. Chern. Abs. v. 47, 

p. 3163i. 

Heating NbC15 and NbC13 in a sealed evacuated tube, one end at 

280° C, the other 20°- 100° cooler, gives NbC14 • 'The cooler end serves 

as a reservoir for NbCl5 , whose vapor represses the decomposition 

of NbC14 • Hydrogen passed over NbCl5 (Chern. Abs., v. 33, p. 81329), 

first at 180° - 190° C and then at 450° C for 18 hours gives NbC13 in 

the hottest part of the tube and NbC14 in an intermediate position. Nb 

with excess NbC15 at 300° C and excess NbC15 vapor over Nb or Fe 

at 400° C for 15 hours or over AI powder or foil at 270° C from NbC14• 

AIC13 can be sublimed away in excess NbC15 vapor. NbC15 is more 

easily reduced than TaC15• Nb02 can not be converted to NbC14 with 

CC14 or SOC1 2, but anhydrous AlC13 + Nb0 2 in a sealed tube at 290° C 

gives. NbC14 + AlOCl. NbC15 at 290° C also converts Nb02 to NbC14 

and Nb0Cl3• The extinction direction for NbC14 crystals is parallel to 

the length of the needles when between crossed nicol prisms. The 

X-ray pattern is different from those of NbC13 and NbC15• NbC14 

is stable in dry air; in moist air it gives off hydrochloric acid and is 

oxidized, the crystals first darkening and then turning white with 

no change in external shape and no deliquescence. Solution in the 

absence of air in a little water or 2 N hydrochloric acid gives a deepblue solution. Adding 2 N hydrochloric acid to the blue solution causes 

no change; a drop of NH3 solution or dilution with water changes the 

color to greenish-brown and then brown. More NH3 gives a dirty-brown 

flocculent precipitate. Oxidizers decolorize the blue solution. NbC14 

heated in air is changed to white Nb0Cl3• The order of increasing 

volatility is NbC13 , NbC14 , Nb0Cl3 , NbC15• When heated in the absence 

of air, NbC14 decomposes to NbC13 and NbC15 unless the decomposition 

is repressed by a pressure of NbCl5 vapor greater than its pressure 

from the NbC14• The quadruple point for NbC13 solid, NbC14 solid, 

NbC15 liquid, NbC15 gas is about 400o C. The composition of NbCd.4 

samples is found by determining the amount of hydrochloric acid freed 

by heating the NbC14 in a stream of moist air and weighing 'the 

ignited residue, or by determining the reducing power on dissolving 

in Fe2 (S04 ) 3 solution and the weight of AgCl obtained from this 

solution. 

220 Schafer, Harold; Bayer, Lisel; and Pietruck, Christel; 1951, The 

Chemistry of niobium and tantalum; [Pt.] 5-The preparation of 

titanium- and tin-free samples of tantalum and niobium: Zeitschr. 

anorg. allg. Chemie, v. 266, p. 140-150 [German]; cf. Chern. Abs., 

v. 47, p. 3164e; Nuclear Sci. Abs., v. 6, p. 108 (no. 847). 

Samples of 250-500 mg pure Nb20 5 or 'Ta20 5, 2 ml CC14 or SOC12, 

and 100- 300 mg Ti0 2 were heated for 24- 30 hours at 270°- 350° C 

for complete chlorination. The products were heated to 110° under 
44:. SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

evacuation first with a water aspirator, then with an oil pump. The 

residue, after conversion to oxide, contained 0.05 percent or less of Ti02 • 

When Sn02 was substituted for Ti02 , SOC12 was not used and the 

chlorination temperature was 380° C. The oxide formed from the 

distillation-separation residue was 0.03 percent or less of Sn02 • Since 

NbC15 ·and TaC15 are soluble in CC14 only· to the extent of 10 mg 

per ml or less, the.· mixed chlorides formed were . _also separated by 

5 extractions with 5 ml portions of CC14 • Air need n·ot be .excluded. 

The residue contained twice as much Ti or Sn as after distillation!. 

Heating COC12 + Nb.2 0 5 for 20 hours at 300° C gave complete forma-

: tion of NbCl5 ; heating Ti0 2 + CC14 at 250° C for 9 hours and Sn02 

+ CC14 at 380° C for 10 hours gave almost _no chlorination; but if the 

~olids were· 50 percent or niore Nb20 5, especially when coprecipitated, 

the -Ahlorinations were complete. Heating Nb20 5 with 'Ta20 5 also lowered 

the te~perature of chlorination of Ta2 0 5 with CC14 well below 320° C. 

221 ·Schafer, Harold, and Pietruck, Christel, 1951," Chemistry of niobium 

·and tantalum; [Pt.] 6-The separation of niobium and tantalum 

through the reduction of niobium pentachloride: Zeitschr, anorg. 

allg. Chemie, v. 266, p. 151-160 [German]; cf. Chern. Abs., v. 47, 

p. 3164g; NuClear Sci. Abs., v. 6, p. 108 (no. 846), 195~ . 

. NbC15 or TaC15 is heated to 200° C in half of a sealed evacuated 

tube. ·In the other half is Nb or Ta at 400° C; The NbCl5 is reduced 

to NbCl4 by both metals; TaCl5 is unchanged. A NbC14 sample exposure 

either to vapqr or melt of a 50-50 mol. percent TaCl5-NbCl5 ·mixture 

. ~ contains only ~.8 -1.2 mol. percent qf TaC14 • A fairly pure Nb prepara-

. tion (analyzing no more than 1.5 percent of 'Ta20 5 } can be precipitated .by_. using no more than 80 percent <;>f the AI needed to change 

all NbCl5 to NbCl4• A fraction containing not more than 14.3 percent 

of Ta20 5 and a fraction containing not more than 12.5 percent of 

· : Nb2 05 :can be obt~ined by using enough· AI to reduce· all NbCl5 to NbC13 

in a sealed evacuated tube at 280° - 300° C for 60 hours. Tantalum 

preparations co11taining l~ss than 0.5 percent of Nb2 0 5 can be obtained 

, .. : 'J)y using. 25 percent excess ·AI. NbCl3 causes very little reduction of 

TaCl5 •. For H2 - reduction mixed chlorides are heated for 24 hours in 

a sealed tube· with. H2 , 10- 40 percent in exces:;; of that ,needed to 

redu<;e the NbC15 to NbC13• The reduced sample collects in the tube arm 

222 

. he~ted to 400° C, and the unreduced sample remains in the tube -arm 

: heated to only 200° C. A stream of H2 ( 1 liter per hour through a 200-

; mm tube 35 mm in diameter) also brings about. selective reduction 

.at 450° C. 

--- 1951, Chemistry of Niobium and tantalum; [Pt.] 7-Note 

.. on the· binary. system niooium pentachloride-tantalum pentachlor.-

ide; Zeitschr. ~prg. allg. ;Chemie, v. 267, p. 174-80 [German]; 

cf. Chern. A_bs., v. 47, p. 3164i; Nuclear Sci.- Abs., .v. 6, p. 254 (no. 

2003)., 1952 .. : . . ' 

The chl~rides w~re prepared by t~eating · pure and mixed Nb and Ta 

·oXides with CC14 at 270°- 300° C• and subliming the ·product into glass 

·ampules. Other preparations of the pure chlorides when fully purified 

... :- ·gav~ ·the ·same melting point. Temperatures were read from a Hg 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 45 

thermometer calibrated to 0.1 o C. NbC15 melts at 204.7° C; TaC15 melts 

at 216.5° C. Liquidus points for mixtures of the two fit very closely 

the line calculated from the Clausius-Clapeyron and Raoult equations 

and the heats of fusion of Alexander .and Fairbrother (Chern. Abs., v. 

43, p. 7851h); the solutions are nearly ideal. The gas phase above 

mixtures of the chlorides is slightly richer in TaCl 5• The low-temperature modification of NbCl 5 of Alexander and Fairbrother is not 

confirmed. Nb0Cl3 is soluble only. to a limited amount in liquid NbC15, 

the saturated solution melting 1 o C lower than pure NbCl5• A solution 

of 1.0 mol. percent WC16 in NbC15 is bright red and has a melting point 

lowered no more than 0.2° C. 

223 Schliessmann, 0., 1941, The sensitivity of spectral analysis of alloy 

components of steel and iron: Archiv Eisenhiittenw., v. 15, p. 

167-174; cf. Chern. Abs., v. 47, p. 8458. 

The limits of sensitivity were ascertained for pure solutions of the· 

usual components of iron and steel. The determinable limits and the 

suitable lines for the respective metals and metalloids are given. The 

elements tested for were AI, As, B, Ba, ·Be, Ca, Co, Cr, Cu, Mg, Mn, 

Mo, Nb, Ni, P,_ Si, Sn, Sr, Ta, Ti, V, W, and Zr. 

224 Schoeller, W. R., 1937, The analytical chemistry of tantalum and niobium; 'The analysis of their minerals and the application of 

tannin in gravimetric analysis: London, Chapman and Hall, Ltd., 

198 p.; cf. Chern. Abs., v. 31, 73644. 

225 Schoeller, W. R., and others, 1921-36. Investigations into the analytical chemistry of tantalum, columbium [niobium], and their mineral 

associates: pts. 1, 2-Chem. Soc. [London] Jour., v. 119, p. 1927-

1935, 1921; pts. 3-33-Analyst, v. 49, p. 215, 1924; v. 50, p. 485, 

494, 1925; v. 51, p. 613, 1926; v. 52, p. 504, 506, 625, 1927; v. 53, p. 

258, 264, 467, 515, 1928; v. 54, p. 320, 453, 704, 709, 1929; v. 55, 

p. 605, 1930; v. 56, p. 304, 795, 1931; v. 57, p. 72, 284, 550, 750, 

1932; v. 58, p. 143, 1933; v. 59, p. 465, 667, 1934; v. 60, p. 284, 

506, 1935; v. 61, p. 235, 449, 585, 806, 1936. 

The investigations were made in the laboratories of The Sir John 

Cass Technical Institute and are separately cited and annotated under 

the names of the individual authors. The following classification of 

their contents gives their reference numbers in this bibliography: 

1. Analytical technique- 227, 235, 247 

2. Tartaric acid method- 231, 240, 243, 248, 251, 252, 254 

3. Separation of tungsten from the earth acids and other earths197, 236, 239, 250 

4. Separation of tannin group A from group B - 241, 244, 245, 

247a, 253 

5. Separation of t~tania from the earth acids - 226, 233, 237, 238 

6. Separation of tantalum from niobium - 196, 196a, 228, 242, 

246 . 

8. General summary- 231 

226 Schoeller, W. R., 1929, Investigation into the analytical chemistry of 

tantalum, columbium, and their mineral associates; [Pt.] 15-A 
46 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

new method for the separation of tantalum and niobium from 

titanium and zirconium (tannic acid method): Analyst, v. 54, p. 

455. 

227 --- 1931, Investigation into the analytical chemistry of tantalum, 

niobium, and their mineral associates; [Pt.] 19-Laboratory notes 

on analytical technique: Analyst, v. 56, p. 304-310. 

228 --- 1932, Investigation into the analytical chemistry of tantalum, 

niobium, and their mineral associates; [Pt.] 24-An improved 

method for the separation of tantalum from niobium: Analyst, v. 

57, p. 750-756. 

229 --- 1934, Zum Nachweis kleiner Mengen von Tan tal und Niob: 

Zeitschr. anal. Chemie, v. 96, p. 252. 

231 ---1936, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 33-General summary and results: Analyst, v. 61, p. 806-811; cf. Chern. Abs., v. 

30, p. 74877; v. 31, p. 6275. 

The chronological sequence in which the experimental results obtained in the study and development of methods for analyzing minerals 

containing Ta, Nb, and their associates Ti, Zr, Hf, Th, Ce, 'Tb, Y, etc. 

have been described was of necessity haphazard. The present paper, 

which marks the end of 17 years of painstaking work, is a classified 

index of the whole investigation and a brief discussion of the results. 

232 --- 1942, Oxidimetric determination of columbium: Analyst, v. 67, 

p. 321-322; cf. Chern. Abs., v. 36, p. 40505; v. 37, p. 3239. 

An electrolytic reduction of Nb5+ to Nb3+ and its titration with an 

oxidizing agent. Method necessitates prior removal of Ta and offers 

no practical advantages over the tannin method. 

233 --- and Deering, E. C., 19'27, Investigations into the analytical 

chemistry of tantalum, columbium, and their mineral associates; 

[Pt.] 9-The precipitation of tungstic acid by tannin; the separation of tungsten from tantalum and niobium: Analyst, v. 52, p. 

625-637. 

235 Schoeller, W. R., and Jahn, C., 1926, Investigation into the analytical 

chemistry of tantalum, columbium [niobium], and their mineral 

associates; [Pt.] 6-The precipitation of the earth acids by sodium 

compounds: Analyst, v. 51, p. 613-620; cf. Chern. Abs., v. 21, p. 

10732. . 

When Ta20 5 is fused with K2C03 and the aqueous extract of the 

melt is treated with NaCl, a precipitate is formed of Na8Ta6 0 9 • 25H20. 

If Nb20 5 is treated similarly, Na1"4Nb120 37 • 32H20 is obtained. 

236 --- 1927, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 7-The precipitation of tungstic acid by tannin; [Pt.] 8-The separation of tungsten 

from tantalum and columbium: Analyst, v. 52, p. 504-514; cf. 

Chern. Abs., v. 21, p. 1073, 38546. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 47 

A llleW method of separation is proposed which depends on the 

fusion of the mixed oxides with K2C03 , precipitation of the resulting 

aqueous solution with NaCl, recovery of the small quantity of nonprecipitated earth acid by hydrolysis in bicarbonate solution and 

precipitation of the W in the filtrate by tannin oand cinchonine. 

237 --- 1929, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 14-A new method 

for the separation of small quantities of tantalum and niobium 

from titanium: Analyst, v. 54, p. 320. 

A tannic acid method. 

238 --- 1932, Investigations into the analytical chemistry of tan tal urn, 

columbium, and their mineral associates; [Pt.] 21-A reliable 

method for the quantitative separation of titanium from tantalum 

and niobium: Analyst, v. 57, p. 72. 

239 --- 1934, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 26-The interference 

of tungsten in earth-acid determinations: Analyst, v. 59·, p. 465. 

240 Schoeller, W. R., and Powell, A. R., 1921, Investigations into the 

analytical chemistry of tantalum, columbium, and their n:Uneral 

associates; [Pt.] 1-The use of tartaric acid in the analysis of 

natural tantalo-columbates: Chern. Soc. Jour., v. 119, p. 1927-1935. 

241 --- 1921, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 2-The separation 

of zirconium from tantalum and from columbium: Chern. Soc. 

Jour., v. 119, p. 1927-1935. 

242 --- 1928, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 11-The precipitation of titanium by tannin: Analyst, v. 53, p. 258-263. 

243 --- 19'28, Investigations. into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 10-The separation 

of silica from the earth acids: Analyst, v. 53, p. 264-267. 

245 --- 1932, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 23-The quantitative separation of tantalum, niobium, titanium, and .zirconium, and 

a new analytical grouping: Analyst, v. 57, p. 554-554. 

246 Schoeller, W. R., and Waterhouse, E. F., 1924, Investigations into the 

analytical chemistry of tantalum, columbium, and their mineral 

associates; The volumetric estimation of columbium: Analyst, v. 

49, p. 215-:-220. 

247 --- 1928, Observations· on the ·pyrosulphate.:.hydrolysis method: 

Analyst, v. 53, p. 467. 

247a --- 1928, Investigations into the analytical chemistry of tantalum, 

columbium, and their. mineral associates; [Pt.] 13-A new method 

for the separation of zirconium and hafnium from tantalum and 

niobium: Analyst, v .. 53, p. 515. 

A further modification of the tannic acid method. 
48 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

248 --- 1932, Investigations into the analytical chemistry of tantalum, 

columbium, and their mineral associates; [Pt.] 22-The separation 

of the earth acids from metals of the hydrogen sulphide group: 

Analyst, v. 57, p. 284-:290. 

249 --. - 1935, Investigations into the analytical chemistry of tantalum, 

columbium [niobium], and their mineral associates;· [Pt.] 28-;-, 

Separation of the rare earths from the earth acids: Analyst, v. 60, 

p. 284-:29'1; cf. Chern. Abs., v. 29, p. 756, 42874. 

'The mineral is decomposed with HF, whereby the earth acids go into 

solution and the rare earths, Th0 2, and alkali earths are left as insoluble fluorides. · 

250 --- 1936, Investigations into the analytical chemistry of tantalum, 

· columbium [niobium], and their mineral associates; [Pt.] 31-

Determination of tungsten in earth-acid minerals: Analyst, v. 61, 

p. 449-455; Chern. Abs., v. 28, p. 57771; v. 29, p. 72191; v. 30, p. 

37416, 63046. : 

The small amounts of W that are commonly present in Ta-Nb 

minerals are precipitated with the earth acids by tartrate hydrolysis at 

fairly high concentrations under standardized conditions; they are 

· de~ermined in the precipitate produced by hydrolysis by the magnesia 

method. 

· 251 Schoeller, W. R., and Webb, H. W., 1929, ·observations on tartaric 

hydrolysis and the quantitative precipitation of the earth acids 

and certain other oxides from tartrate solution: Analyst, v. 54, 

p. 709. 

Papers 16 and 17 of the Schoeller series. 

252 -·-- 1931, Investigations into the analytical chemistry of 'tantalum, 

columbium [niobium], and their . mineral associates; . [Pt.] 20-

The separation of tin from tantalum and niobium: Analyst, v. 56, 

p. 795-801. 

253 --- 19•33, Investigations into the analytical chemistry of tantalum, 

columbium [niobium], and their mineral associates; [Pt.] 25-

Separation of uranium from Ta, Nb and Ti: Analyst, v. 58, 

143-147. 

Like the earth acids and the rare earths, U is precipitated completely 

by the addition of tannin to a neutralized tartrate solution containing 

NH4 0Ac and NH4Cl. It is also precipitated from oxalate solution by 

tannin in the presence of a slight excess of NH3 • Uranium, like Zr, Th, 

Al, and Fe, can be separated from Ta, Nb, and Ti ·by adding tannin to 

the faintly acid oxalate solution half sat:urated with NH4Cl. In tartaric 

hydrolysis, U interferes )Vith the normal precipitation of Nb. 

254 -· -- 1934, Investigations into the analytical chemistry of tantalum, 

· niobium, and their mineral associates; (Pt.] 27-0bservations on 

manganese and the analysis of tantalite: Analyst, v. 59, p. 667-671; 

cf .. Chern. Abs., v. 28, p. 57771; v. 29, p. 755. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUN~, 1953 49 

A scheme of analysis ·is recommended for tantalite and columbite 

which is based on the analytical procedures already described in this 

series of papers. 

255 --- 1936, Investigations into the analytical chemistry of tantalum, 

columbium [niobium], and their 111ineral associates; [Pt.] SOObservations on beryllium: Analyst, v. 61, p. 235-241; cf. Chern. 

Abs., v. 6, p. 2725;, v. 29, p. 42874, 72191; v. 30, p. 37416. 

The earth-acid precipitate obtained by boiling the tartrate solution 

with an excess of mineral acid does not include BeO. Tannin precipitation from oxalate solutions half saturated with NH4Cl separates 

Ti, Nb, and Ta from Be as well as from Zr, 'Th, Al, U, etc. 

256 --- 1936, Investigations into the analytical chemistry of tantalum, 

columbium [niobium], and their mineral associates; [Pt] 32-

0bservations on P, V, and a tannin precipitation series: Analyst, 

v. 61, 585-590; cf. Chern. Abs., v. 30, p. 63046, 74877. 

To recover P 20 5 from a Nb, Ta, and P precipitate with tannin, it is 

fused with NaOH and the melt extracted with half-saturated NaCl 

solution. Na3P04 dissolves, but the Na salts of Ta20 5 and Nb20 5 are 

practically insoluble. Traces of V give tannin precipitate of earth 

acids a blue-black. color. In oxalate solution which is half-saturated 

with NH4Cl, Ta, Nb, and Ti are precipitated by tannin completely, 

while Zr, Th, AI, U, and Be remain in solution. The order in which 

precipitation with tannin alone takes place is Ta, Ti, Nb, V, Fe, Zr, 

Hf, Th, U, and AI. Only an elaborate system of repeated crystallization 

will separate two adjacent members of the series by tannin precipitation. Position of Cr in series is not yet known. 

257 Schofield, M., 1945, Tantalum: Indus. Chemist, v. 21, p. 207-209·; cf. 

Chern. Abs., v. 39, p. 25922. 

P~st history and present uses. 

258 Schwarz, Victor, 1947, Chemical analytical studies on niobium and 

tantalum-A new volumetric method for determining niobium in 

the presence of tantalum: Rev. Minera, Geologia y Mineralogia, 

v. 18, no. 1, 2, p. 13-24; cf. Chern. Abs., v. 46, p. 2445d. 

Comparison of the location of Nb with that of Ta in the periodic 

table is followed by a discussion of the oxidation levels of the two 

elements. The reactions of their oxalates in the presence of tannic acid 

is reviewed as is the reactions of H2Se0 3 with Nb, Ta, Ti, and other 

rare elements. A new method for determining Nb is described that 

depends on reduction with amalgamated Zn, oxidation of the reduced 

Nb with a known excess of FeC13 , and titration with 0.1 N TiC13 solution with KCNS as indicator. 

259 Scott, W. W., 1939, Standard methods of chemical analysis, v. 1: 5th 

e~., New York, D. Van Nostrand Co. 

Collected information on analytical methods and procEtdures. 

261 Shakhov, A. S., 1939, Application of polarographic method to the determination of lead and tin in potassium fluoroxy columbates and 
l.5Q SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

metallic columbium: Zhur. priklad. khimii, tom 12, p. 1555 

[~rench, p. 1559']. 

262 Shapiro, M. Ya., 1938, Sensitive test for tantalum and columbium: 

· Zhur. priklad. · khimii, v. 11, p·. 1028-1032 [French, p. 1032]; cf. 

Chern. Abs., v. 33, p. 16241. 

With rhodamine B, 0.2 gamma of Ta can be detected by the violet 

color and flaky precipitate, but Mo, W, Hg, Au, Sb, and Fe interfere. 

The fine-grained, grayish-blue precipitate with 0.1 percent aqueous 

methylene blue is sensitive to 1 gamma of Ta but W, Mo, V, Sb, Sn, and 

AI interfere at high concentrations. Gentian violet, in 0.1 percent 

aqueous .solution, gives coarse violet flakes when 0.4 gamma of Ta 

is present, but alkali salts of W, Nb, V, and Sn interfere. Nb can 

be detected. with pyrocatechol and strong N aOAc solution by the 

yellow color when . 0.4 gamma of Nb is present, but minerals acids, 

Fe, and Ti interfere. After· reduction with SnC12 , 1.0 gamma of Nb can 

be detected by the yellow color in the absence of Mo, W, V, and 

much mineral acid. 

263 Shemyakin, F. M., and Pilipenko, V. A., 1938, Reactions of columbium 

and tantalum with resorcinol: Zhur. obshchey khimii, v. 8, p. 824-

827 [English, p. 828]; cf. Chern. Abs., v. 33, p. 4973, 12358. 

Examination by the method of Gibbs showed that contrary to 

Platonov and others (Chern. Abs., v. 31, p. 46149), Nb and Ta do not 

give characteristi.c color reactions with resorcinol in alkaline solutions, 

as distinct from the blue-green or green-yellow reactions of resorcinol 

alone with NH4 0H and KOH. Resorcinol with salts of Ce, Th, Pr, La, 

Zr, and U in NH4 0H solutions forms blue-green precipitates which 

differ but .little in the shades. If KOH instead of NH4 0H is used, 

yellowish and gray precipitates are formed. 

264 Slavin, Morris; 1946, Tantalite of the northeast [of Brazil]; its exportation and analysis; [Pt.] 2-Analysis of tantalite-columbite concentrates: Brazil, Lab. Produ~ao Min. Bol. 21, p. 27-58; cf. Chern. 

Abs., v. 31, p. 73644; v. 42, p. 7674c. 

This is a modification of Schoeller's tannin method. The entire procedure is diagrammed. Time required for the analysis has been cut 

from about 15 days to 4 to 5 days. 

265 Smith, G. Frederick, 1938, Cupferron and neo-cupferron: Columbus, 

Ohio, F. Frederick Smith Chern. Co., 42 p. 

Determination of niobium and tantalum with cupferron is described. 

266 Snell, F. D., and Snell, C. T., 1949, Colorimetric methods of analysis: 

3d ed., New York, D. Van Nostrand Co., v. 2, chap. 28, 29. 

The colorimetric determination of Nb and Ta with pyrogallol, 

peroxide, reduction of fluoride, and hydroquinone are given in detail. 

267 Societe generale metallurgique de Hoboken, 1939, Separating columbium 

from tantalum: France patent 846,584, .September 20, 1939; cf. 

Chern. Abs., v. 35, p. 11952. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 51 

Ores containing Ta and Nb are mixed with a base, such as CaO, 

and chlorinated at a temperature not above 1050° C. Nb is volatilized 

as the chloride. 

268 --- 1947, Separation of columbium, tantalum, and similar metals: 

Belgium patent 470,891-2, February 1947; cf. Chern. Abs., v. 43, 

p. 976bc. 

Nb2 0 5 i8 reduced selectively, preferably with H2, to Nb0 2, without 

acting on the Ta, and part of the Nb is removed by chlorination to the 

volatile NbC15• 

Niobium is selectively nitrided. The nitride is treated with Cl2, Br2, 

I 2, or a dissociable compound thereof, to convert it selectively into a 

volatile halide, which is separated from Ta20 5 by distillation and 

condensation. 

269 --- 19'40, 'Treating of tantalum- and columbium-containing materials: German patent 695,788, August 1, 1940; cf, Chern. Abs., 

v. 35, p. 56583; British patent 507,124 (Chern. Abs., v. 34, p. 5968), 

270 Srinivasan, N. R., 1950, Studies on niobium and tantalum; [Pt.] 3-

Tartratoniobates of alkaline earths and other metals: Indian 

Acad. Sci. Proc., v. 31A, p. 381-388; cf. Nuclear Sci. Abs., v. 5, 

p. 11 (no. 78), 1951. 

271 --- 1952, Studies on niobium and tantalum; [Pt.] 5-Tartratotantalates: Indian Acad Sci. Proc., v. 36A, p. 278-283, Chern. Abs., v. 

4 7, p. 4238a, 4 777 h. 

Treatment with mineral acids precipitates tantalic acid. Alkali 

hydroxides also decompose the tartratotantalates. In general, they are 

similar to the tartratoniobates. 

272 Stromberg, A. G., and Reinus, L. M., 1946, Polarographic study of 

columbium solutions in nitric acid: Zhur. fiz. khimii, v. 20, p. 

693-705; cf. Chern. Abs., v. 41, p. 343h. 

No polarographic wave is obtained for Nb solutions in HCl, H2S04 , 

tartaric acid, salicylic acid, KN08 + pyrogallol, and NH4 oxalate. 

If Nb20 5 is fused with K2C08 and then dissolved in HN08 , the solution 

gives a wave the height of which is proportional to the concentration 

"X" of Nb between 0.19' and 1.12 millimol. per liter, independent of 

the concentration "Y" of HN0 8 between 0.2 and 2 N. 

Niobium solutions in other acids do not show polarographic waves, 

presumably because their reduction potentials are more negative than 

that of H2• 

273 --- L. M., 1949, Polarographic investigation of niobium: Akad. 

nauk SSSR, Otdel. khim. nauk, Trudy Kom. anal. khimii, v. 2, no. 

5, p. 34-53; cf. Chern. Abs., v. 44, p. 9299b. 

Niobium can be determined polarographically only in acid nitrate 

solution. 

274 Siie, P., 1933, Determination of niobium with 8-hydroxyquinoline: Acad. 

sci. [Paris] Comptes rendus, tome 196, p. 1022. 
: 52 SELECTED BIBLIOGRAPHIES OF ANALYTICAL .CHEMISTRY 

275 --- 1937, Contribution to the study of the columbates: Annales 

chimie, v. 7, p. 493-59·2; cf. Chern. Abs., v. 15, p. 2380; v. 30, p. 

33085; v. 31, p. 69911. 

:rreparation and properties of various niobates: N a, K, Li, Cu, Co, 

Ni, Zn, Al, alkaline earths, Ag, Tl, etc. 

276 Syrokomski, V. S., and Klimenko, N. G., 1947, Determination of 

.columbium in presence of titanium: Zavodskaya lab., tom 13, p. 

1035-1038; cf. Chern. Abs., v. 43, p. 4177c. 

After removal of Si02 with HF • H2S04 , fuse residue with KHS04 

and extract melt with H2S04 'in presence of H 2 0 2 ; reduce Ti with 

Zn-Hg in a separatory funnel; add NH4 0Ac, adjust pH to 1.5, boil, 

filter off precipitate; ignite,-weigh, and analyze precipitate colorimetrically for Ti. 

277 'Takagi, Katsuki; and Shimizu, Yukimi; 1950, Application of tantalum 

to potentiometriG titrations; [Pt.] 1-Several potentiometric titrations with tantalum electrodes: Electrochem. Soc. Japan Jour., 

v. 18, p. 150-152; cf. Chern. Abs., v. 45, p. 8392h. 

Some potentiometric titrations with the Ta electrode are described, 

including acidimetry with Ta-Ta oxide electrodes and titration of 

chloride· with AgN03 with Ta-Pt electrodes. 

278 Taylor-Austin, E., 1940, Chemical analysis of alloy cast iron: Foundry 

Trade Jour., v. 63, p. 201-202, 220-222, 230; cf. Chern. Abs., v. 35, 

p. 24415, 

A brief description is given of the analytical procedure for determining the following elements in alloy cast iron: C, Si, Mn, S, P, Ni, Cr, 

Cu, Al, 'Ti, V, W, Zr, As, Sb, Sn, Mo, Co, Ta, and B.. The use of 

org~nic reagents in inorganic analysis is discussed. 

279 Telep, G., and Boltz, D. F., 1952, Ultraviolet spectrophotometric determination of columbium: Anal. Chemistry, v. 24, p. 163-165; cf. Nuclear Sci. Abs., v. 6, p. 179 (no. 1405). 

An investigation was undertaken of conditions under which Nb can 

. be determined spectrophotometrically as perniobic acid. Formation of 

the perniobic acid complex in a concentrated acidic mixture of H 2SO4 

and H 3PO 4 results in a stable yellow hue exhibiting maximum absorbancy in the ultraviolet region. 'The system conforms to Beer's Law at 

342m mu. The optimum concentration using 1-cm cells is from 0 to 125 

parts per million of niobium. The effects of acid concentration, H 20 2 

concentration, and diverse ions were determined. The· main interferences are due to ferric, molybdate, vanadate, titanic, tungstate. 

nitrate, chloride, and fluoride ions. 

280 Thanheiser, G., 1940, Method for the photometric det&rmination of 

columbium and tantalum in steel, ferrous alloys, and slags: KaiserWilhelm Inst. Eisenforsch. Dusseldorf Mitt., v. 22, p. 255-265: 

cf. Chern. Abs., v. 35, p. 24388. 

Method based· on the yellow coloration of Nb with ·H2 0 2 in a concentrated H 2SOcH3 P04 solution. Forty percent H3 P04 (ratio of 2 
NIOBIUM AND TANTALUM, JANUARY .1935-JUNE, 1953 ·53 

acids) suppresses the Ti coloration (unless more than 1 percent Ti). 

The basis for the photometric determination of Ta is the yello;w coloration produced with pyrogallol in 3 percent NH4 oxalate sol~tion. Since 

Ti also gives a yellow coloration with pyrogallol, it must be: determined 

independently and a correction applied. (use chro~otropic acid in same 

sol uti on). -

281 Thurstan, A. W., 1941, Estimation of tantalum and .columbium: Sydney 

·Tech. Coli. Chern. Soc. Jour·. and Proc., v. 8;. p. 36-43, 1938-40; 

cf. Chern. Abs., v. 35, p. 68936. . . 

A review. 

282 Tikhomiroff, Nicolas, 1953, Separation of niobium and tantalum by 

chromatography on activated alumina: : Acad. sci [Paris]' Comptes 

rendus, tome 236, p. 1263-1265 [French]; cf. Nuclear Sci. Abs., v. 

7, p. 371 (no. 3044). 

The separation of Nb and Ta is based on the absorption of the two 

elements from oxalic solution on activated alumina and. their elution 

at different pH's. Ta is only partially retained on alumina. 

283 · Tomicek, Oldrich, and Holecek, Vacalv, 1952, The analysis of niobium 

and tantalum; [Pt.] 3-Application of morin and quercetin for 

testing and gravimetric estimation of niobium and tantalum: 

Chern. listy, v. 46, p. 11-14; cf. Chern. Abs., v. 46, p. 3900/. 

Morin and ·quercetin form red precipitates with Nb and orange precipitates with Ta. 'The qualitative test is best carried out in str~ngly 

acidic solutions containing 20-25 percent volume for volume H2S04 

by adding alcohol solutions of the agents (15 mg _in 3 ml EtOH). Ti 

gives a dark-red precipitate even in neutral solutions. Reprecipitation 

is advisable. 

284 Tomicek, Oldrich, and Jerman, Ladislav, 1952, The analysis of niobium 

and tantalum; [Pt.] 4-Colorimetric determination of niobium 

and tantalum: Chern. listy, v. 46, p. 144-:148; cf. Chern. Abs., v. 

46, p. 11024h. . 

Ta and Ti form with pyrocatechol a yellow coloration in (NH4 ) 2C2 0 4 

solution. Nb forms a similar coloration in NH3 solution. In a mixture of 

Nb or Ti with Ta, Nb or Ti can be determined colorimetrically after 

electroreduction which does not affect Ta. In oxalate solution Ti can 

be reduced, but not Nb, with amalgamated Zn. The extinction maximum 

· for the ·colored complexes of Nb, Ti, and Ta are 400 - 440 m mu. 

Procedure: A sample (10 to 100 mg of oxides) is fused with 3 g 

KH~0 • The melt is dissolved in 50 ml (NH4 ) 2C2 0 4 solution and diluted to 10 mi. An aliquot is treated with 5 ml 10 percent solution of 

pyrocatechol and diluted with a saturated solution of (C02NH4 ) 2 to 

25 ml. Determination of Nb or Ti in the presence of Ta was made 

after electroreduction, and determination of Ti in the presence of Nb 

and Ta after reduction with Zn amalgam in the Jones reductor. 

285 Tomicek, Oldrich, and Spurny, Kvetoslav, 1952, The analysis of niobium and.tantalum; [Pt.] !-Cathodic reduction of ;niobium: Chern. 

listy, v. 46, p. 6-8; cf. Chern. Abs., v. 46, p. 3900e. 
54 SELECTED BIBLIOGRAPHIES OF ANALYTICAL-CHEMISTRY 

;Reductio~ of Nb with ZnHg proved unsuccessful. Good results were 

·obtained by electroreduction of Nb5+ in 26 percent H2SO4 on a Hg 

cathode in a ~pecial apparatus. Nb3+ thus- formed is oxidized with Fe3+ 

and the resulting Fe2+ is titrated with 0.01 N Ce(S04 ) 2 with o-phenanthroline as indicator. The presence of Ta does not interfere. Ti is also 

reduced quantitatively. 

2~6 -· -.-... - 1952, 'The analysis of niobium and tantalum; [Pt.] 2-Volumetric estimation of titanium in the presence of niobium and 

tantalum: Chem.listy, v. 46, p.-9-11; cf. Chern. ·Abs., v. 46, p. 3900/. 

Ti salts are reduced with ZnHgx in 25 percent ·tartaric ·acid in a 

.,:-;. ·· stream of H 2 , even in the presence ·of Nb, Ta, Y, and Fe. Ti3+ ions 

are titrated potentiometrically with 0.05 N FeCl3 at 80° C in a stream 

·.of H 2, or with methylene blue or NH4CNS as indicator. The method 

is suitable for determining Ti, Nb, and Ta in steels an9. o:r:es. 

287 'Tompkins, E. R., Khym, J. X., and Cohn, W. E., 1947, Ion exchange 

' :Jl;r: r. '· :.:r: 'as· a separation method; [Pt.] 1-The separation of fission-pro-

-duced isotopes,· including individuai rare earths, by complexing 

elutions from Amber lite resin: Am. Chern. Soc. Jour., v. 69, p.' 

2769-277.7; cf. Chern. Abs., v. 42, p. 1834h.. -

Application of · ion-exchange technique to the separation of the 

.·major fission species using. Amberlite. IR-1. Factors affecting separations were studie9. with respect. to rare earths, 'Th, Nb, Zr, and alkalies. 

288 Touhey, w·. 0., and Redmond, J. C., 1948, Analysis of cemented carbide 

... compositions: Anal. Chemistry, v. 20, p. 202-206; cf .. Chern. Abs., 

v~ 42, p. ·.36991~ · 

Deterlnine W, Ti, Nb; Ta, Fe, Co, Ni, and AI by know:n methods, 

which have been modified slightly and require careful attention to 

details,' such as the recovery of Ti, Nb, Ta, etc. from the first W03 

precipitate.· · 

2.89 ·Traub~ K. N., 1946, H-examethylenetetramine in separations of titanium 

all:d c~lum'!>ium: Indus. Eng. Chemistry,' Anal. ed.,' v. 18, p. 122-

124; Chern. Abs., v. 40, p. 17495 .. 

· ·Precipitate Nb + Ti with hexamethylenetetramine, dry, ignite, and 

· :weigh as Ti0 2 + Nb20 5• Then determine 'Ti colorimetrically with H20 2• 

290 Treadwell, F. P., and Hall, W. T., 1932, Analytical chemistry: 9th ed., 

'. New York, John Wiley and Sons, v. 2, p. 224-226; cf. Analyst, 

v. 54, p. 453, 1934; v. 57, p. 72, 750. 

Procedure is given for the separation of Nb from Ta with tannin. 

291 Treaqwell, W. D., and others, 19'52, Determination of niobium and 

tantalum 'in columbite and euxenite: Helvetica Chiril. Acta, v. 35, 

.P· 2248-2259 [German]; cf. 9hem; Abs., v. 47, p. 2634a; Nuclear 

Sci~ Abs., v. 7, p. ·129 (no. 1065). 

The minerals were subjected to dry chlorination by heating at 500° C 

· for 8 hours in a current of hydrochloric acid gas charged with CC14 • 

By this method TiC14 can easily be separated from the more volatile 
NiOBIUM AND TANTALUM, JANUARY 1935-jtiNE, 1953 55 

chlorides of Nb, Ta, U, and Fe; and after reduction of the FES+ to Fe2+, 

by using S02 , Nb and Ta are quantitatively precipitated as hydroxides. 

Experiments were made to reduce solutions of niobic acid in H2S04 

by means of Zn, and a reproducible method with good yields is described. 'The potentiometric titration of NbS+ sulfate with KMn04 is 

discussed, and some informative spectroanalytic experiments with a 

mixture of Nb20 5 and Ta2 0 5 are mentioned. 

292 Treadwell, W. D., and Nieriker, R., 1942, Oxidimetric determination of 

columbium by itself and in the presence of iron, vanadium, and 

titanium: Helvetica Chim. Acta, v. 25, p. 474-488; cf. Chern. Abs., 

v. 36, p. 40505. 

Method employs an electrolytic reductor; the solution is titrated 

with KMnO 4 and the end point determined potentiometrically. 

293 Tschernikov, J. A., and Karsajevskaya, M. P., See Chernikhov, Ya. A., 

and Karsayevskaya, M. P. (48a). 

294 Uspenskaya, T. A., and Chernikhov, Yu. A., 1940, Application of the 

iodate method to the separation and determination of the rare 

elements: Acad. sci. U. R. S. S. Comptes rendus, tome 28, p. 800-

801 [English]; cf. Chern. Abs., v. 35, p. 24404. 

Ce an'd Th are precipitated as iodate and the precipitates made the 

basis of a gravimetric or volumetric determination of Ce and Th. Similar 

precipitates can be obtained with Zr and Ta. Nb is not precipitated by 

KI03 , hence reaction can be used for separating Ta and Nb. Details 

concerning procedure not given. 

295 Vail, J. H., 19'44, Modified rapid method for Cb: Chemist Analyst, v. 33, 

p. 14-15; cf. Chern. Abs., v. 38, p. 19741, 

A procedure is suggested for determining Nb, Si, Cr, and Ni, but 

no definite analytical data are given with respect to its reliability. 

296 Van VaJkenburgh, H. B., and Crawford, T. C., 1941, Detection of 

certain metals in mineral and ores - an ammonium hypophosphite fusion method: Indus. Eng. Chemistry, Anal. ed., v. 13, p. 

459-460; cf. Chern. Abs., v. 35, p. 54109, 

Fuse 0.1, g of finely powdered material with NH4H2P02• 'The mass 

has a melting point of about 60° C after fusion becomes quiet. The 

color of the melt or the color resulting from treatment with water 

or hydrogen peroxide solution will serve for detecting Cr, Co, Nb, Mn, 

Mo, Te, Ti, U, V, and W. To test for Nb, add concentrated hydrochloric acid to melt, boil, and add a little mossy Sn, which gives an 

intense blue color. 

297 Vinogradova, N. A., and Gushtyuk, E. I., 1945, A rapid method for the 

analysis of loparite concentrates: Zavodskaya lab., tom 11, p. 

223-226; cf. Chern. Abs., v. 40, p. 11142, 

The method proposed is rapid and gives sufficiently accurate 

results. Niobium and Ta are separated from Ti and Fe by tannin 

method; Ta is determined colorimetrically with pyrogallol in (C2 0 4 )H2 

solution; and rare earths are separated from oxalic acid solution. 
.~,~~ . S~LECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

.?~~ . Vq:p. Hevesy, G .. , and Bohn, J., 1927, Determination of tantalum by 

' .. 'means of. X-ray spectra:, Zeitschr. anorg. alig. Chemie~ v. 164, p. 

69'--80; cf. Chern. Abs., v. 21, p. 31728. -

299 Voznesenski, S. A., 1934, Inner-complex salts: U~pekhi khimii, v. 4, 

p. 531-562; cf. Chern. Abs., v. 29, 7323. 

A review on the metallic derivatives of a variety of substances, 

chiefly organic, such as glycocoll, picolines, amino, · and other sub-

·Stituted acids, aliphatic and aromatic amines of various types, phenols, 

·.esters, ketones, and aldehydes. Among the metals considered are Cu, 

Zr, Th, Ta, K, and Fe. Their applications· in analytical chemistry are 

discussed. 

300 Wacker, R. E., and Baldwin, W. H., 1950, The separation of zirconium 

and niobium oxalate complexes by anionic exchange: ORNL-637; 

.. cf. Nuclear Sci. Abs., v. 4, -p. 469 ,(no. 3018), British Abs., v. c, p. 244, 1951. ,. ' ' . 

I·, 

It was found that Zr and Nb are adsorbed on Dowex-1 resin from 

oxalic ac.id solution (0.1- 0.4 M) and can be preferentially eluted (Zr 

being removed first) with 1 M hydrochloric acid and 0.01 M oxalic 

acid solution. 

301 . Waterkamp, M., 1949, The determination of columbium and tantalum 

in steels: Archiv Eisenhiittenw.~ v. 20, . p. 5-8; cf. Chern. Abs., v. 

43, p. 4597 h. 

302 

· . The. properties of the salts of Nb and 'Ta which are useful in 

analytical chemistry are carefully reviewed, and 6 procedures are 

.described for dete.rmi~ing Nb and Ta. 

Weiser, Bruno, 1941, Progress in the inorganic heavy-chemical industry; 

[Pt.] 14-Heavy-metal compounds and others: Chern. Fabrik, v. 14, 

p. 248-255, 281-286, 302-305; cf. Chern. Abs., v. 35, p~ 49227; v. 

38, p. ' 53694. ' ~~ r f'' 

A r~v:iew of about 943 patents and papers between 1933 and Decem-

~ .. ·.,·. ~er 31, 1940 on compounds of Fe, Cu, Zn, Ct, Mn, Ni, Co, V, Mo, W, 

- U, Nb, Ta, sn·, Hi, Hg, Au, Zr, Th, Pt, Pd, Rh, Ru, Ge, Ra, Tl, and In, 

with many references. or:r:-~- .. · 

~ ·ao3· Wenger, P., Duckert, R., and Rusconi, Y., 1945, Critical study of 

,; .. re.agents for cations; [Pt.] 13-Reagents for the cations of the 

,:·.. rare earths and yttrium: Helvetica· Chim. Acta, v. 28, p. 274-278 

[French]; cf .. Chern. Abs., v. 37, p. 53356, s; v. 38, p. 62286; v. 40, 

304 

p. 5_295. 

A discussion of the reagents: oxalic acid, NH4 succinate, ~~ cacothe-

_li;ne, and quinaliz3:rine. Elements discussed were the rare earths: Th, 

S_c~ Hf, ·zi:, Nb; Ta, Ba, Sr, Ca, ·u, AI, and Fe. 

Wernet, Josef, 1952, The behavior of titanium, niobium, and tantalum 

. compounds in hydrochloric acid as a foundation for a new preparative separation method: Zeitschr. anorg. allg. Chemie, v. 267, p. 

213-237 [German]; cf. Nuclear Sci. Abs., v. 6, p. 298 (no. 2344); 

Chern~ Abs., v. 46, :P~ .~484/. 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 57 

With. the intention of sep'arating Ti as (NH4 ) 2TiC16 from Nb and 

Ta, the author has studied the behavior of various compounds of these 

elements, particularly the hydrated oxides and chlorides, in highly 

concentrated hydrochloric acid, and the reaction of these solutions with 

NH4Cl. The Ti precipitates in every case as (NH TiC1 ~ The Ti 

content of a mixture containing approximately 3 percent Ti0 2 . ~n 

Nb20 5 was reduced to less than 0.07 percent Ti02 in one step by this 

method. In a mixture of 50 weight percent Ti0 2 and Ta20 5, the separation resulted in approximately 1 percent Ti0 2 remaining in the Ta20 5• 

In a Ti-Nb-Ta mixture with a Ti :Nb ratio greater than or equal to 2, 

the Nb precipitated with the (NH4 ) 2 TiC16 • This coprecipitation suggests a way of separating both these elements from Ta. .. r ··•.• 

305 Williams, A. E., 1940, Estimation of tantalum and columbium as com-

. bined oxides: Chern. Eng. Min. Rev., v. 32, p. 271-272; cf. Chern. 

Abs., v. 34, p. 46915. 

For determining (Ta, Nb) 20 5, the Schoeller method is used. 

306 Williams, A. F., 1952, Inorganic chromatography on cellulose; [Pt.] 12 

-The quantitative determination of tantalum and niobium in complex minerals, ores, and synthetic materials: Chern. Soc. [London] 

Jour., p. 3155-3163, cf. Nuclear Sci. Abs., v. 6, p. 771 (no. 6308), 

A new chromatographic method for the quantitative separation of 

Ta from Nb and for their determination in certain types of mixtures, 

based on cellulose as absorbent and ethyl methyl ketone containing 

HF as solvent, was described as Part 11 of this seri~s [see reference 

40 of this bibliography]. This method has been modified so that it is 

now applicable to the quantitative determination of these elements in 

complex materials containing appreciable amounts of 'Ti, Sn, and Zr. 

A solution of sample in HF containing ammonium fluoride being used, 

Ta is extracted first in ethyl methyl ketone saturated with water. 

The column is then washed with ketone containing 1 percent (volume 

per volume). of HF (40 percent weight per weight aqueous ·solution) 

which arrests the movement of Ti, Sn, and Zr. Niobium is then extracted with the ketone containing 12.5 ·percent of HF. After removal 

of solvent the Ta and Nb are determined in the appropriate fractions 

by ignition to the pentoxides. 

The procedure is simple and accurate and has been ·used. for the 

analysis of a wide range of natural and synthetic· materials. 

307 Winkler, J. E. R., 1940, Absolute colorimetry in the metal industry: 

Schweizerische Archiv angew. Wiss. u. Technik, v. 6, p. 194-201; 

cf. Chern. Abs., v. 34, p. 77798. 

The author reviews fundamentals of absolute colorimetry and describes the Pulfrich photometer. He describes the range of application, 

method, time, and interference by other elements for the determination of each of the following elements in steel: AI, Cr, Co, Cu, Mn~ 

Mo, Ni, Nb, P, Si, N, Ti, V, 3.ll:d W. 

308 Wirtz, H., 1939, Separation of tantalum and columbium: Zeitschr. anal. 

Chemie, v. 117, p. 6-9; cf. Chern. Abs., v. 33, p. 67482. 
58' S~LECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

In presence of bromphenol blue indicator all Ta and · very little 

Nb can be precipitated by means of tannin. Before this treatment, 

determine the sum of Nb 20 5 and Ta20 5 as usual. 'The small quantity 

of Nb · in the tannin precipitate can be determined by dissolving the 

oxide, reducing in a Jones reductor and titrating with KMn04 • · 

309. --- 1941, Separation of columbium and tantalum: Zeitschr. anal. 

Chemie, v. 122, p. 88-94; cf. Chern. Abs., v. 31, p. 6275; v. 33, 

p. 67482; v. 36, p. 47731. 

Author recommends tannin separation of Schoeller to determine Nb 

and Ta. Very little Nb ·is precipitated with Ta at the proper pH. 

310 Wood, G. A., 1950, The determination of total Ta and Cb in minerals 

and· ores by solvent extraction in presence of activated cellulose: 

· CRL-AE-62; cf. Nuclear Sci. Abs., v. 5, p. 288 (no. 1802), 1951. 

A chromatographic method is described for the separation of mixed 

Ta ·and Nb oxides . from minerals and ores by. extraction of fluorides 

with methyl ethyl ketone containing HF in presence of activated cellulose. NH4F is used to inhibit extraction of a number of other metals~ 

After removal of solvent, the Ta and Nb are precipitated with tannin 

and weighed as oxides. · 

.3'11 Yager, J. C., 1937, Tantalum-its occurrence, properties, and uses: 

A-ustralian Chern. Jnst. Jour. and Proc., v. 4, p. 59-65; cf. Chern. 

Abs., v. 31, p, 33496. 

313 Yatsenko, V. G., and Basse, A. P., 1937, Separating columbium and 

tantalum salts: Russian patent 51,125, May 31; Chern. Abs., v. 33, 

p. 47504. ' 

Salts of Nb and Ta are separated by hydrolysis of their fluorides. 

'The HF separated thereby is combined with metallic Zn or similar 

electronegative metal. The insoluble K4 Ta40 5F 14 separates from solution. 

314 Yoshida, Yukito, 1942, Quantitative study of fusions with an alkaline 

oxidizing flux: Chern/ Soc. Japan, Jour., v. 63, p. 439-451, 615-628; 

cf. Chern. Abs., v. 41, p .. 301lb. 

The results obtained by fusion with a flux composed of 3 parts 

· NaOH, 2 parts KN0 3, and 1 part K2C03 are tabulated for compounds 

of Cu, Ag, Ca, Ba, Zri, Hg, B, AI, Ce, La, silicates, phosphates, niobates, 

selenites, tung~tates, and numerous other compounds. 

315 Yu, Pe-Nien, 19'48, A modified method in the analysis of uranium ore 

with high content of columbium and tantalum: Chinese Chern. Soc. 

Jour.,· v. 15, .p. 170-178; cf. Nuclear Sci. Abs., v. 1, p. 547 (no. 

1969). ' 

Scott's method was modified by fusing the ore with K2S2 0 7 and 

extracting with hot water. The U is precipitated by NH3 and weighed 

as U3 0 8• 

316 Zeltzer, S., 1932, Polarographic studies with the dropping mercury 

cathode~ [Pt.J 25-An i;nvesti~atiop of solution~ of ~allium, tita,n-
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 59 

ium, vanadium, niobium, and tantalum: Coli. Czechoslovak Chern. 

Commun., v. 4, p. 319. 

317 Zemel, V., 1936, Chemical analysis of black and ruby sands: Soviet-· 

skaya zolotopromyshlennost, no. 3, p. 50-51; cf. Chern. Abs., v. 30, 

p. 80638. 

This procedure makes it possible in one sample to determine W, V, 

and Mo and to detect Sm, Ta, Nb, Th, Zr, and rare earths. 

318 Zvyagintsev, 0. Ye., and Namoradze, Z. G., 1938, New quantitative 

reactions of columbium and tantalum: Zhur. obshchey khimii, v. 

8, p. 829; cf. Chern. Abs., v. 31, p. 46149; v. 33, p. 4973. 

Reactions of Nb and Ta with resorcinol does not give a qualitative 

test for these elements. 

AUTHOR INDEX 

(This index to the authors of papers listed in the bibliography is arranged alphabetieall:v 

by the anglicized form of the name. Accent marks, including the umlaut, have been disregarded · 

in the arrangement. The numbers following each name listed in the index correspond to 

reference numbers that precede the citations listed in the bibliography] 

Aarnseth, K. A. 164 

Abramov, F. I. 1 

Adler, N. 181 

Afanas'yev, B. N. 2 

Aleksuvskaya, N. V. 3 

Alimarln, I. P. 4, 6, 6, 7, 8, 9, 10 

Arglla, J. S. 12 

Atkinson, R. H. 13, 116 

Bachelet, M. 14 

Bacon, F. E. 160 

Bagshawe, I. B. 16, 16 

Bailey, N. H. 17 

Baldwin, W. H. 300 

Barber, E. J. 19 

Barber, H. 18 

Basse, A. P. 313 

Batik, A. L. 116 

Baumann, W. 78 

Bayer, Llsel 216, 219, 220 

Beck, G. 20 

Bernhardt, H. A. 19 

Bhattacharya, H. 21 

Birks, L. S. 23, 24 

Bleyenheuft, L. 26 

Blinov, V. I. 26 

Blokhin, M. A. 27, 31 

Bohn, J. D. 298 

Boltz, D. F. 279 

Borneman-Starninkevitch, I. D. 28 

Borovskli, I. B. 29, 30, ·s1 

Bottcher, H. 184 

Bouissieree, G. 14, 32 

Box, F. W. 69 

Breckpot, R. 33 

Breil, GUnther 216 

Brode, W. R. 36 

Brooks, E. J. 23, 24 

Brubacker, C. H. 37 

BrUning, K. 38 

Budanova, L. M. 39 

Burkser, L. E. 67 

Burova, T. A. 6 

Burros, C. L. 100 

Burstall, F. H. 40, 41 

Bykova, V. S. 42, 43, 44 

Calvin, M. 1'61 

Carriere, E. 46, 46 

Carroll, J. 81 

Chernikhov, Yu. A. (Chernikov, I. A.; Tschernichov, I. A.) 47, 48, 48a, ~94 

9la«r~ ll:f W: 4~ · 

Cohn, W. E. 287 

Colin, L.L. 60 

Cordovi, M. A. 61 

Cottin, M. 62, 63 

Crawford, T. C. 296 

Creffier, J. 33, 64 

Gropper, F. R. 66 

Cunningham, T. R. 66, 79 

Daublander, J. 77 

Davydov, A. L. 57 

I;leering, E. C. 233 

Delaney, J. C. 58 

.Qoan, U. M. 69, 60 

I;>obina, A. A. 61 

Duckert, R. 303 

Dunham, H. S. 62 

Duval, C. 59, 60 

Edwards, J. W. 63 

Eeckhout, J. 88, 89 

Efendiev, E. M. 64 

Eichholz, G. G. 65 

Elson, R. E. 66, 67 

Elwell, W. T. 16 

~startus, F. G. 68 

Evans, B. S. 69 

fairbrother, F. 70 

Farrar, R. L. 20 

Fedorov, A. 71 

Fink, C. G. 72 

Fleischer, M. 73 

Fowler, R. M. 74 

Fred, M. 62 

Freund, H. 76 

Frid, B. I. 6,· 7, 8, 9 

Frith, w. c. 70 

Fucke, H. 77 

funk, H. 78 

Furey, J. J. 79 

Gastellier, S. 112 

Gatterer, A. 80 

G'avrilova, K. D. 39 

Geld, I. 81 

Gentry, C. R. 82 

Gest, H. 83 

Gibson, K. S. 84 

Gilbert, P. T. 85 

Giles, W. B. 86 

Gillis, J. 87, 88, 89 

Giratto, A. 90 

Glendenin, L. E. 83 

Goldbersuch, E. 91 

Golc;IVch~n~r~ Ya •. · 140 
62 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Golubtsova., R. B. 92, 93 

Gorba.ch, G. 94 

G'oryushima, V. G. 47 

Goser, Ca.mill 219 

Goto, Hidehiro 95 

Grzhibovskaya, L. A. 81 

Grube, G. 96 

Grube, H. L. 96 

Guiter, H. 45, 46 

Gul'dina, E. I. 97 

Gushtyuk, E. I. 297 · 

Hagiwara, Hisato 98 

Hahn, R. B. 99, 100 

Haissinsky, M. 53, 101 

Hall, W. T. 290 

Hamer, A. 55 

Harder, J. 0. 73 

Harpham, E. W. 102 

Hartmann, H. 103 

Harvey, C. E. 104 

Hayashi, Shigehiko 105, 106, 107, 108 

Haywood, F. W. 109 

Hecht, H. 110 

Herman, P. 111, 112 

Hillebrand, W. R. 118 

Hilliard, J, W. 114 

Hiskey, C •. F. 13, 115, 116, 181 

Holecek, V. 283 

Holt, M. L. 117 

Hopkins, B. S. 118 

Huffman, E. H. 119, 120 

Hume, D. N. 121, 155 

Iddings, G. M. 119, 120 

Ikeda, Tadasi 130 

Indichenko, L. N. 122 

Jaboulay, B. E. 123 

Jahn, C. 197, 235, 236, 237, 238, 239 

Jander, G. 110 

Jean, M. 124 

Jeffries, Z. 128 

Jeng-Tsong, Yang 101, 126 

Jerman, Ladislav 284 

Johnson, C. M. 127, 128 

Johnston, H. L. 63 

Junkins, J. H. 19 

Kakita, Yachiyo 95 

Karsayevskaya, M. P. (Karsajevskaya, M. P.) 

48, 48a 

Karyakin, Yu. V. 129 

Kats, G. A. 166 

Katsura, Tetsuo 107, 108 

Khokhlova, A. V. 166 

Khym, J. X. 287 

Kiba, Toshiyaso 130 

Klimenko, N. G. 131, 276 

Klinger, P. 132, 133, 134, 135 

Klinkenberg, P. F. A. 136 

Knowles, H. B. 187 

Koch, W. 133, 184 

Kohn, Andre 188 

Komarovskii, A. S. 139 

Komatsu, Manryn 211 

Komovskii, G. F. 140 

Kraus, K. A. 142, 148, 144, 145 

Krasilllhchjkov~ B, s. Ul, l46 

Krishnaswami, K. R. 147 

Krivoshlykov, N. F. 148, 149, 188, 189, 190 

Kroll, W. J. 150 

Kuznetsov, V. I. 151, 152, 153 

Kvalheim, A. 154 

Kwan, Li Mou 184 

Lauw-Zecha, A. B. H. 155 

Leddicotte, G. W. 156 

Lehmann, H. 215 

Levitt, A. E. 76 

Libby, R. C. 120 

Lokka, Lauri 157 

Lomonosova, L. S. 168 

Long, J. V. P. 159 

Lord, S. S. 156 

Lowe, A. J. · 169 

Lundell, G. E. F. 113, 137 

Mackay, R. A. 160 

Maraka'yev, A. A.· 189, 190 

Martell, A. E. 161 

Martini, A. 162 

Masatoshi Miyamoto 177, 178 

Massing, W. 103 

Maurer, W. C. 163 

Mercer, R. A. 165 

Meerson, G. A. 166 

Meier, K. 38 

Meimberg, E. 164 

Melent'yev, B. N. 167 

Miller, C. C. 169 

Miller, C. F. 168 

Milner, G. W. C. 170 

Miyamoto, Masatoshi 177, 178 

Moir, J. 171 

Moore, F. L. 156 

Moore, G. E. 142, 143, 144, 145 

More, C. 172 

Murthi, D. Suryanarayana 147 

Myers, R. H. 173 

Nachtrieb, N. H. 174 

Namoradze, Z. G. 176, 318 

Newman, L. 115 

Nieriker, R. 292 

Novikov, V. A. 17'6 

Oka, Yoshinafa 177, 178 

Osborn, G. H. 179 

Oshman, V. A. 180 

Owen, L. E. 68 

Palilla; F. C. 181 

Pearson, J. G. 182 

Pe-Nien, Yu 316 

Pennington, M. E. 183 

Pfeiffer, P. 184 

Pietruck, C. 217, 218, 220, 221, 222, 260 

Pigott, E. C. 185, 186, 187 

Platonov, M. S. 3, 61, 149, 188, 189, 190 

Platonova, A. F. 193 

Podval'naya, R. L. 10 

Poehlman, W. J. 191 

Pohl, F. 94 

Pokrovskaya, T. L. 192 

Poma, K. 89 

Popova, N. M. 141, 146, 193 · 

Portnov, A. I. 194 

Pc;>rtn9V, 1'4. A, 196 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 63 

Powell, A. R. 196, 196a, 

242, 248, 246 

Prlitorius, W. 184. 

196b, 197, 240, 241, Syrokomski, V. S. 181, 276 

Tadasi, Ikeda 180 

Prede, A. F. 198 

Prodinger, W. 199 

Rankama, Kalervo 201, 202 

Rasmussen, S. W. 208 

Redmond, J. C. 204, 288 

Reimus, L. :M. 272, 278 

Rodden, C. J. 208 

Rogers, B. 206 

Rohmer, R. 206 

Rosenthaler, L. 207 

RutY, 0. 208 

Rusconi, Y. 303 

Rutlin, S. 154 

Sanderson, L. 209 

Sandell, E. B. 210 

Sarnowski, R. E. 191 

Sato, Ichiro 211 

Savchenko, G. S. 212 

Sawaya, Tsuguo 213 

Schlifer, H. 214,. 215, 216, 217, 218, 219, 220, 

221, 222 

Schlapmann, H. 110 

Schleissmann, 0. 223 

Schoeller, W. R. 196, 196a, 196b, 197, 225, 226, 

227, 228, 229, 231, 232, 233, 235, 236, 

287, 288, 239, 240, 241, 242, 243, 245. 

24.8, 247, 247a, 249, 250, 251, 252, 258, 

254, 255, 256. 

Schofield, M. 257 

Schwan:, V. 258 

Scott,. W. W. 259 

Shafer, H. 260 

Shakhov, A. S. 261 

Shapiro, M. Ya. 139, 262 

Shemyakin, F. M. 268 

Sherrlngton, L. G. 82 

Shimizu, Yukimi 277 

Slavin, M. 264 

Smith, G. F. 265 

Snell, C. T. 266 

Snell, F.D. 266 

Speiser, R. 63 

Spurny, Kvetosla.v 286, 286 

Srinivasan, N. R. 270 

Steigma.n, J. 13 

Stengel, E. 135 

Stromberg, A. G. 272, 273 

Sl1le, P. 274, 275 

Suryanarayana. Murthi, D. 147 

Swain, P. 40, 

Takagi, Katsuki 277 

Tanana'yev, I. B. 212 

Taylor-Austin, E. 278 

Telep, G. 279 

Telezhnikova, P. M. 129 

Terekhovko, A. S. 167 

Tetsuo Katsura 106, 107 

Thanheiser, G. 280 

Thomas, F. 208 

Thurstan, A. W. 281 

TikhomirotY, Nicolas 282 

Tobin, W. J. 174 

Tomicek, 0. 283, 284, 285, 286 

Tompkins, E. R. 287 

Tosiyasu, Kiba 130 

Touhey, W. 0. 288 

Traub, K. W. 289 

Treadwell, F. P. 290 

Treadwell, W. D. 291, 292 

Tschernicbov, J. A. See Chernikhov, Yu. A. 

Uspenskaya, T. A. 294 

Va.il, J. H. 295 

Vaisberg, Z. M. 57 

Van Den Berg, G. J. 136 

Van Valkenburgh, H. B. 296 

Vasyunina, N. A. 153 

Vinogradova, N. A. 297 

von Hevesy, G. 298 

Voznesenski, S. A. 299 

Wacker, R. E. 300 

Waterhouse, E. F. 246, 247, 247&, 249, 250 

Waterkamp, M. 301 

Webb, H. W. 251, 252, 253, 254, 255, 256 

Weiser, B. 302 

Wenger, P. 303 

Wernet, J. 304 

Williams, A. E. 305 

Williams, A. F. 40, 41, 

Winkler, J. E. R. 807 

Wirtz, H. 38, 135, 308 

Wood, A. J. 170 

Wood, G. A. 40, 310 

Ya.chiyo Kakita 95 

Yatsenko, V. G. 313 

Yoshida, Yukito 314 

Young, R. C. 37, 91 

Yu, Pe Nien 316 

Zeltzer, S. 816 

Zemel, V. 317 

166, 806 

Zvyagintsev, 0. Ye. 175, 818 

SUBJECT INDEX 

[This index should be used as the starting point in locating data included in the literature 

listed and summarized in the bibliography. Considerable care has been exercised in t\le indexing 

to provide adequate reference to the information. Double indexing has been used where it 

seemed desirable. The numbers following the subjects listed in the index correspond to 

reference numbers that precede the citations listed in the bibliography] 

Acetone, in colorimetric determination of Nb 

71) 

Acidimetry 277 

Activation assaying 65 

Ald~hydes 299 

Aliphatic amines 299 

Alumina 282 

Aluminum 15, 88, 98, 97, 185, 187, 211, 255, 

266, 262, 278, 803, 807 

Amalgam 180 

Amberlite IR-1 286 

Amberlite IR-4B 126 

Amberlite resin 121,, 126, 286 

Aminobenzenearsonic acids lfi8 

Aminopyrine 108 

Ammonium oxalate 18a, 42, 146, 189, 272 

Ammonium succinate 308 

Antimony 72, 109, 162, 163, 162, 262, 278 

Antipyrine 108 

Aromatic amines 194 

Aromatic arsenic compounds 194 

Arsenic 16, 61, 88, 162, 182, 186, 187, 192, 

278 

2- ( o-Arsonophenylalo) -p-cresol 151 

S- ( o-Arsonophenylazo) -4,6 dihydroxy-2, 7-

naphthalenedisulfonic acid 161 

1-( o-Arsonophenylazo) -2-naphthol 

18,6-disulfonic acid 161 

1-( o-Arsonophenylazo) -2-naphthol 

-6,8-dlsulfonic acid 161 

Barium 126, 803 

Benzenearsonic acid 6, 7, 8, 77 

1-Benzoinoxime 94 

Beryllium 16, 61, 68, 72, 126, 180, 185, 21S, 

266 

Betainelike complex salts 184 

Bibliography (ion-exchange resins) 179 

Bismuth 68, 162, 158, 162, 802 

Black sands 817 

Boron 98, 186, 187, 207, 278 

Bourdon-type sickle gage 70 

Bromphenol Blue 308 

Brucin~ 108 

Cacotheline 20, 303 

Cadmium 51, 72 

Calcium 72, 90, 93, 126, 130, 803 

Carbon 79, 162, 186, 187, 278 

Carbon disulfide 176 

Carbon tetrachloride 176, 208 

Cassiterite 28, 192 

Cathodic reduction 285 

Cellulose chromatography 40, 41, 305, 810 

Cerium 30, 31, 72, 182, 11:!6, 187, 281, 263, 294 

Chelate compounds 161 

Chemical spectroscopy 86 

Chevenard balance 69, 60, 180 

Chlorination 18, 116, 267, 268, 291 

Chloroform 94, 175 

Chromatography 40, 41, 166, 282, 806, 810 

Chromium 14, 81, 46, 61, 58, 88, 109, 163, 

186, 187, 278, 295, 302, 807 

Chromotropic acid 183, 134, 135, 280 

Cinchonine 105, 235 

Cobalt 14, 31, 51, 52, 68, 79, 88, 125, 140, 

182, 186, 187, 204, 278, 302, 807 

Colorimetric detection 296 

Colorimetry S, 9, 10, 16, 47, 61, 76, ·at, 92, 95, 

112, 183 134, 185, 146, 148, 149, 154, 

188, 188, 189, 210, 269, 262, 268, 266, 

276, 279, 280, 284, 296, 297, 307, 808 

Columbates, See niobates. 

Columbite 40, '68, 112, 160, 230, 264, 291 

Columbium See Niobium. 

Complex fluorides 212, 218 

Complex formation 89 

·Complex salts 46 

Copper 14, 51, 88, 109, 162, 182, 185, 187, 278, 

299, 802, 807 

Cunningham procedure 206 

Cupferron 56, 79, 94, 167, 266 

Determination of niobium and tantalum 166, 

159, 177, 268, 286 

absorptiometrio p~cedure 170 

in alloys 40 

in AI 84 

analytical methods 25, 118, 118 

comparative study 25 

analytical techniques 227, 229 

assaying 66 

in basic Bessemer slag 18 

with benzenearsonic acid 6, 7, 8, 77 

bibliography 26 · 

in black sands 817 

in carbide compositions 198, 204 

in cassiterite 28, 192 

in east iron 278 

by cellulose chromatography 40, 41, 806, 

810 

in cemented carbide compositions 28S 

by chemical analysis 206 

by chromatography 40, 41, 282, 306, 810 

in 18 Cr-8 Ni stainles11 steel 191 

65 
66 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Determination of niobium and tantalum-Con. 

classical methods 34 

colorimetric methods 3, 9, 16, 47, 61, 76, 

92, 95, 141, 146, 154, 181, 188, 189, 

193, 200, 210, 259, 266, 279, 280, 

284, 297. 307. 308 

with H20: 81, 92, 112, 133, 134, 135, 

181, 2616 

with KCNS 164, 171, 183 

· with pyrogallol 148, 149, 193 

in columbite 112, 254, 265, 291 

as combined oxides 9, 10, 17, 18, 38, 43, 

56, 97. 102, 123, 141, 146, 147. 157. 

180, 188, 208, 214, 217. 220, 297. 

305, 308, 309, 310, 315 

as combined. oxides with SiO: 77 

in complex salts 46 

in concentrates 47 

Cunningham procedure 205 

in drug ash 207 

drying temperature of precipitates 130 

in euxenite 291 

by extraction 306, 310 

electrometrically 195 

in ferroalloys 47, 123, 133, 134, 280 

in ferroniobium 38, 97, 123, 138 

ferrotantaloniobium 38 

in ferrotantalum 38, 123 

with gallic acid 93 · 

.rravimetric methods 47, 59, 60, 224, 259, 

283 

by halogenation 208, 214-221 

by halogenation with CC14 208 

in high-alloy steels 92 

in high-alloyed alloys 93 

in high-temperature alloys 81 

by hydrolysis 11 

with hydroquinone 266 

with 8-hydroxyquinoline 130, 274 

ignition temperature of tannin complex 

108 

interference of W 239 

interference of Ti and Zr 6 

by ion exchange 143 I 

by iron 114, 185,_.186, 223 · 

in iron ores 122 

in loparite 3, 43, 297 

in manganese ores· 122 

in metallurgical analysis 109 

in metals 11, 307 

·in meteorites 201 

in minerals 8, 9, 25, 40, 41, 138, 140, 154, 

157, 201, 231, 254, 3~6. 810 

with morin 283 

Nb carbide in stainless steel 163, 198 

Nb-Ta systems by X-ray fluorescence 23, 

24 

Nb:Oo 163, 295 

in niobate 112, 254, 264, 291 

Noyes and Bray system 169 

in ores 8, 9, 40, 41, 47, 64, 201, 286, 806, 

310 

by oxalate-salicylate method 42 

as oxide 4, 8, 9, 16, 67, 180, 135, 170, 289, 

306, 310 

Determination of niobium and tantalum-Con. 

oxidimetrically 232, 258, 285, 292 

with oxine 130, 274 

as perniobic acid 11U, 279 

in perovskite 167 

by phosphomolybdate method 57 

photometrically 11, 84, 57, 138, 134, 135, 

157, 181, 280, 284 

with pyrogallol 280 

by physiochemical analysis 185, 186 

polarographically 84, 49, 195, 272, 273 

by K2S:01 (tannin) method 42 

potentiometric titration 286, 291, 292 

in powdered Ta 158 

in presence of iron 292 

titanium 16, 133, 134, 136, 177, 276, 

280, 286, 292 

vanadium 292 

, procedures 301 

with pyricatechol 284 

with pyrogallol 95, 141, 146, 188, 189, 

266, 297 

pyrolysis curve& 59 

with quercetin 283 

by radioactivity 138, 159 

radioniobium 100 

in rare earth minerals 206 

by reduction of fluoride 266 

with zinc amalgam 258 

removal of Ti and Zr interference 6 

with resorcinol 189 

review 15, 16, 281, 307 

review on estimation 281 

in rocks 41, 201 

in ruby sands 317 

in samars'Kite 90 

by Scheibe and Rivas method 88 

by Schoeller method 224-264 

by Schoeller and Powell method 5'6, 112, 

305 

by Schulze method 154 

.by Scott method 815 

by Schwarz method 48a 

in silicates 8 

simultaneous determination 181 

in slags 280 

in soevite 154 

in soils 64 

spectrochemical analysis 64, 174, 181, 191 

spectrographically 33, 54, 58, 62, 88, 104, 

110, 122; 140, 191, 201, 223 

spectrographically in presence of Zr and 

Hf 62 

speetrophotometrically 76, 155 

spectrophotometrically (ultra violet) 279 

spectroscopically 26, 71, 94, 109 

in stainless steel 26, 56, 127, 191 

in stainless steel (18 Cr-8 Ni) 191 

standard methods 259 

in steel 15, 39, 47, 57, 88, 114, 123, 133, 

134, 141, 146, 186, 186, 205, 223, 

280, 286, 301, 307 

in steel alloys 71 

with steeloscope 26 

by ·sublimation 214-221 
.NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1958 67 

Determination of niobium and tantalum-Con. Gold 130, 168, 182, 262, 302 

summary of methods 281 Hafnium 23, 24, 29, SO, 120, 140, 168, 196b, 

in synthetic materials 41, 806 231, 247, 803 

with tannin 17, 48, 60, 98, 102, 108, 112, Hafnium, determination in Zr by X-ray 

154, 196, 196a, 805, 808, 809, 310 fluorescence 28, 24 

in tantalite 280, 264, 264 Halogenation 214-221, 291 

in tantalocolumbates. See in tantalonio- Hexamethylenetetramine 289 

bates. High-alloy steels 92 

in tantaloniobates 60, 240 High-temperature alloys 81 

in tantalum group 169 Hilger spectrograph 64 

as thiocyanate complex 10, 76, 166 Hydrogen 185 

by titration with KMnO, 11, 178 Hydroquinone 126, 266 

titrimetrically 11, 218, 282 8-Hydroxyquinoline 94, 274 

in W-bearing steels 102 Indium 20, 51, 72, 93, S02 

in tungsten carbide 69, 79 Infrared spectroscopy 66 

volumetric methods 46, 47, 48a, 66, 98, Inner-complex salts 299 

137, 177, 246, 269, 285, 808 Inorganic cellulose chromatograp~y 40, S06, 

volumetrically with KMnQ, 11, 178 SlO 

volumetrically with TiCla 258 Iodine S03 

in uranium ore 816 

in wolframite 48 

by X-ray fluorescence 61 

X-ray spectra 27, 298 

by X-ray spectroscopy SO, Sl 

Direct-current arc method 104 

Distillation 1S 

Dithizone 94 

Double fluorides 14 

Dowex-1 144, 800 

Dowex-2 120 

Dropping mercury cathode 316 

Drug ash 207 

Earth acids (see also Cb and Ta) 235, 289, 

24S 

EDTA 116 

Electro-reduction 284, 286 

Esters 299 

Ethyl bromide 176 

Ethylenediamine 176 

Ethylenediaminetetraacetic acid 116 

Ethyl methyl ketone 40, S06, 310 

Eudialytes 29 

Euxenite 291 

Extraction 84, 40, 118, 155, 156, 306, SlO 

Extraction of fluorides 40, 806, 310 

Ferrocolumbium. See Ferroniobium. 

Ferroin 89 

Ferroniobium 88, 97, 188 

Ferrotantaloniobium 88 

Ferrotantalum 88 

Film reaction in mineralogical analysis 176 

Fission products 287 

Flame photometry 85 

Fluorescence 160 

Fluorine 182, 21S 

Formaldehyde 4, 182 

Fractional erystallizati9n 14, 69 

2-Furaldehyde 16S 

Gallic acid 93, 129 

Gallium 61, 72, 93, 207, 816 

Gentian violet 262 

Geochemistry 78, 201, 202 

Germanium 49, 51, 72, 93, 802 

Glycocoll 299 

Ion exchange 119, 120, 148, 146, 179, 287, 800 

Iron S, 51, 68, 79, 90, 109, 168, 186, 187, 192, 

204, 262, 292, 299, S02, 80S 

lsonitrosoacetophenone 94 

Isopropyl ether 76 

Isotopic exchange 62 

Ketones 299 

Lanthanum SO, S1, 9S, 162 

Lead S1, 180, 140, 152, 185, 187, 261 

Lithium 72, 125, 182 

Loparite 3, 4S, 297 

Magnesium 27, 72, 90, 109, 192 

Manganese 14, SO, 81, 61, 68, 72, 79, 88, 88, 

90, 109, 116, 182, 187, 192, 207, 230, 

278, 302, S07 

Mercury 72, 168, 262, 802 

Mercu'ry cathode 285 

Methyldioctylamine 156 

Methylene blue 262 

Methyl ethyl ketone 40, 41, 166, 170, 806, 310 

Molybdic acid 168 

Molybdenum 14, 20, 89, 46, 61, 68, 68, 72, 88, 

93, 109, 140, 152, 163, 187, 204, 205, 

262, 278, 302, 307. 317 

Morin 20, 283 

B-naphthol 78 

N eocupferron 265 

Neodymium 30, 31, 93 

Neutron irradiation 169 

Nickel 51, 79, 88, 109, 122, 140, 182, 187, 204, 

278, 295, 302, 307 

Niobates 261 275, S14 

Niobium 16, 31, 72 

action of thionyl chloride on Nb20G 93 

analysis 283, 286 

analytical chemistry 13, 11fi, 197, 213, 

224-268, 290, S01 

analytical methods 20S, 259, 231 

analytical techniques 227, 229 

anion exchange studies 143, 145 

aromatic arsenic compounds 194 

betainelike complex salts 184 

bibliography 124, 182 

bibliography (1930-1942) 185 

in black sands 317 

in carbide compositions 19S, '204 
68 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Niobium-Continued 

in cassiterite 28, 192 

in cast iron 278 

cathodic reduction 286 

cellulose chromatography 166, 806, 810 

in cemented carbide compositions 288 

chelate compounds · 161 

chemical properties 198 

chemistry 173, 214, 217, 220, 221, 222 

chlorination 13, 115, 291 

chlorination with octachloropropane 116 

chromatography 165, 282, 806, 310 

colorimetric detection 296 

colorimetric determination 9, 10, 128, 183, 

276, 279, 307 

colorimetric reaction 210, 266 

colorimetric test 262, 263 

color reactions 61 

with arsono acids 151 

color tests,· with aminobenzenearsonic acid 

153 

2-furaldehyde 153 

gallic acid 129 

organic reagents 162 

polyphenols 129 

pyrocatechol 129 

pyrogallol 129 

in columbite 40, 164, 254, 264, 291 

complex fluoride compounds 212, 213 

complex sulfates 91 

complexing with tartaric acid 240 

concentration . with organic reagents 94 

critical review 13 

detection 213, ll17 

with cacotheline 20 

by fluorescence 160 

in metals 6 

in minerals 6 

with morin 20 

in rocks 6 

with tannin 196, 196a 

by ultraviolet· light 160 

determination, ·of lead in metallic Nb 261 

determination in presence of Ta 258 

distillation 13, 116 

in drug ash 207 

electrochemical potential 53 

electrochemistry 96 

electrolysis in phosphate melt 103 

electrolytic polishing 53 

electrolytic preparation 72 

electrolytic reduction 232, 284, 292 

electroreduction 284, 285 

elemental analysis by flame photometry 85 

euxenite 291 

extraction 118 

with CHCh of organic complexes 94 

with ether 10 

of fluoride 40, 165, 170, 306, · 310 

with isopropyl ether 76 

with methyldioctylamine in xylene 

156 

with methyl ethyl ketone 40, 41, 165, 

170, ·so6, 310 

of thiocyanate complex 82, 165 

Niobium-Continued 

in ferrous alloys 280 

film reactions 176 

fusion of niobates 314 

geochemistry 73, 201, 202 

halides 70 

halogenation 93, 214, 217, 219, 220, 221, 

291 

halogenation with CC4 208 

in high-alloyed alloys 98 

high-temperature structure 63 

hydrolysis 101 

ignition temperature of tannin complex 

108 

infrared spectroscopy 55 

inner complex salts 299 

interference of W in determination 239 

in loparite 3, 297 

in loparite ores and concentrates 43 

metallurgy 173 

in metals 307 

in minerals 41, 49, 19Gb, 254, · 231, 296, 

306, 310 

in niobates 275, ·su Nb carbide in stainless steel 163 

NbB+-complex sulfates 91 

Nbll+-complex sulfates 91 

Noyes and Bray system 169 

occurrence 172 

in ores 41, 64, 286, 296, 306, 310 

organic complexes 94, 101 

organic derivatives 299 

organic reagents 94, 199, 278 

oxalato complex 300 

oxidation with FeCh 258 

oxidimetric determination 292 

perniobic acid 279 

in perovskite 167 

pH of precipitation 181 

phosphomolybdate complex 57 · 

photometric determination 11 

physical properties 198 

polarographic investigation 273 

polarography 272, 316 

in powdered Ta 158 

precipitation, with benzenearsonic acid 

'6, 7 

cupferron 167 

formaldehyde · 4 

hexamethylenetetramine 289 

morin 283 

na compounds 235 

Na hypophosphite r; 

phenols 4 

quercetin 283 

tannin 290, 297, 808, !J09, 310 

precipitation from tartrate solution 250, 

261 

procedures for determination 301 

production and properties 172 

purification 91 

purification of preparations 214, 221 

in pyrochlore 40 

qualitative reactions 318 

with pyro~allol 189 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 69 

Niohium-Continued 

qualitative reactions-Continued 

with resorcinol 189 

qualitative tests, in foundry materials 

187 

in iron 187 

in steel 187 

radioniobium 100 

in rare earth minerals 206 

reaction of chloride with B-naphthol 78 

reaction of chloride with phenol 78 

reaction. with ammonium succinate ~0~ 

ca.cotheline 303 

gallic acid 93 

gentian violet 262 

hydrogen peroxide 266. 280 

hydroquinone 125, 266, 274 

iodine 308 

methylene blue 262 

organic reagents 190 

oxalic acid ~03 

oxine 274 

potassium thiocyanate 82, 183 

pyrocatechol 262 

pyrogallol 266 

quinalizarine 303 

resorcinol 263, 318 

rhodamine B 262 

selenious acid 258 

tannin 93 

reagents for detection 87, 303 

reduction, general 178 

to Nb4+ with H2 147 

with dropping Hg cathode 316 

of fluoride 266 

with H202 and succinic acid 56 

with liquid mercury 98 

at Hg cathode 285 

of Nb5+ and Nb4+ 67 

of NbCio 221 

of oxide with CaH2 166 

Niobium-Continued 

stabilization of thiocyanate color system 

76 

in stainless steel. 56 

in stainless steel (18 Cr-8 Ni) 191 

standard tests 162 

in steel 11, 146, 193, 280, 286, 301 

sublimation 214, 217, 220, 221 

summary of analytical methods 231 

in synthetic materials 306 

in tantalite 164, 254, 262 

in tantalo-columbates. See in tantalo-nio· 

bates. 

in tantalocolumbites 176 

in tantaloniobates 50, 240 

tartrate hydrolysis 266 

tartaroniobates 270 

test as per-acid 139 

thermal expansion 63 

thiocyanate complex 10, 76. 164, 171 

titration with cerium sulfate 286 

treatment of Nb-Ta containing materials 

269 

ultra violet absorbency 279 

uses 172 

in uranium ores 316 

volatilization as chloride 208, 219, 267 

volumetric determination 46, 48a, 177. 

178, 246, 268, 285 

in wolframite 48 

X-ray spectral analysis 30, 31 

NbBl':l 37 

NbCb 20, 37, 219, 291 

NbCl1 219 

NbCl5 214-222 

NbF5 19, 40, 41, 70, 306, 310 

Nb205 3, 4, 8, 9, 10, 16, 17, 18, 38, 39, 43. 44, 

46, 56, 81, 93, 97. 102, 123, 141, 146. 

147. 157. 180, 188, 208, 214, 216, 217. 

220, 297, 306, 308, 309, 310, 316 

Nitrates 182 

with zinc amalgam 

285 

86, 137, 164, 268, Nitrobenzene 176 

references 302 

review 172, 198, 301 

of analytical chemistry 47 

of 1936 developments 61 

of estimation 281 

of literature 173 

of papers (1933-1940) 302 

of patents (1933-1940) 802 

in rocks 49 

in ruby sands 317 

~emimicro analysis 169 

sensitive tests 262 

separation methods 132 

separative reactions 13 

in slags 280 

in soevite 164 

in soils 64 

solvent extraCtion 306, 310 

spectra 66, SO 

spectral analysis 54, 223 

spectrochemical analysis 68, 64, 174 

llpectl'OJ)hotometric determination 279 

Nitrogen 16, 307 

2-Nitroso-1-naphthol 94 

Noyes and Bray system 169 

Octachloropropane 13, 116 

Organic complexes 101 

Organic reagents 162, 190 

Organometallic compounds 2, 4, 6, 7 

Oxalic acid 218, 303 

Oxine 94, 130, 274 

Pallidium (Pd) 51, 72, 302 

Percolumbic acid. See perniobic acid. 

Perniobic acid 81, 279 

Perovskite 167 

o-Phenanthroline 286 

Phenols 4, 78, 222 

Phosphoric acid 168 

Phosphorus 93, 109, 186, 187, 266, 278, · 307 

Photometry 11, 34, 57, 133, 134, 135 

Picolines 299 

Picrolonic acid 130 

Platinum 63, 302 

Platinum metals 72, 126 

Polarography 34, 41!, 196, 261,. 272, 273, 316 
70 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Polonium 72, 125 

Polyphenols 129 

Porous electrode technique 58, 62 

Potassium 299 

Potentiometry 277, 291, 292 

Praseodymium (Pr) 31. 93, 263 

Protoactinium (Pa) 14, 101, 130, 145 

Pyrocatechol 129, 262, 284 

Pyrochlore 40 

Pyrogallol 6, 8, 95, 125, 146, 148, 149, 188, 

189, 193, 266, 272, 280, 297 

Pyrolysis curves 59, 60 

Qualitative chemical tests 187 

Quercetin 283 

Quinalizarin 303 

Radium 49, 72, 125, 302 

Rare earths 90, 151, 303, 317 

Separation from Nb and Ta 249 

Spectra 80 

Rare ·metals and minerals 125 

Rare-earth minerals, decomposition with H2S04 

1 

Resorcinol 189, Z63, 318 

Rhodamine B 262 

Rhodium ( Rh) 20, 51, 302 

Roentgen tube 140 

Rubidium (Rb) 51, 72 

Ruby sands 317 

Ruthenium (Ru) 51, 302 

Salicylaldoxime 94 

Salicylic acid 42, 272 

Samarium (Sm) 51, 317 

Samarskite 90 

Scandium ( Sc) 80, 303 

Scheibe and Rivas method 88 

Selenium (Se) 15, 51. 72, 125, 186, 187 

Separation of niobium and tantalum ; from AI 

255, 256 

with alumina 282 

with amalgam 180 

with Amberlite IR-4B 126 

analytical methods 226 

with anion-exchange resins 142 

attack of earth-acid minerals 113, ll8 

with benzenearsonic acid 77 

from Be 255, 256 

with brucine 107 

by cellulose chromatography 40, 165 

from cerium with KI03 294 

by chlorination 13 

with octachloropropane 115 

chromatography 39, 165, 282, 306, 310 

coseparation with Mn 83 

with cupferron 79, 265 

hy distillation 13 

with Dowex-1 300 

with Dowex-2 120 

in drug ash 207 

of earth acids from other elements 47, 

116 

with ethylenediaminetetraacetic acid 116 

with ferroin in HF solution 89 

from ferrous oxide 25 

by halogenation with CC14 208 

with HF 249 

with H202 • NaHC03 77, 181 

from H2S group 248 

by ion exchange 119, 120, 121, 12'6, 145, 

287 

from iron 297 

from loparite 3 

from MnO 25, 83, 116 

by Marignac method 38 

methods 113, 118, 132 

with methyldioctylamine in xylene 156 

by Noyes and Bray system 169 

with neocupferron 265 

by oxalic acid method 218 

as oxides 150, 218 

from Pa by ion exchange 145 

from protoactimium 14, 32. 126. 145. 312 

from rare earths 249, 297 

in rare earth minerals 206 

by reduction of NmCla 221 

by regulated hydrolysis 79 

review of methods 44, 68 

by Schoeller method 305 

from Si02 25, 243 

with NaOH 79 

by solubility of combined oxides in am-

- monium oxalate 17 

summary of methods 231 

with tannic acid 226 

tannic acid method reviewed 168 

with tannin 21, 43, 253, 255, 256, 306, 

308, 309, 310 

tantalum group 169 

by tartrate hydrolysis 250, 261 

from Th 266, 256, 294 

from Sn 214, 217, 220, 262 

from Sn02 26 

from titanium 44, 180, 196b, 214, 217, 

218, 220, 226, 233, 237, 238, 245, 

268, 297, 804 

from titanium as (NH•h TiC16 304 

from titanium by oxalate· method 218 

from titanium by oxalate-salicylate methorl 

42 

from titanium by K2S201-tannin method 

42 

from titanium with tannin 242 

from Ti and Zr with pyrogallol 8 

from Ti02 26, 218 

from tungsten 197, 218, 233, 236, 260 

from tungsten oxide 25 

from uranium 170, 263, 266, 266 

by volatilization 214-221, 267 

from zirconium, general 120, 180, 196b. 

226, 241, 246, 247a, 266, 266, 294 

by anionic exchange 300 

by ion exchange with Dowex-1 143 

with KIOa 294 

Separation of niobium from tantalum 17, 74. 

123, 146, 212, 213, 226, 228, 258, 269. 

306, 308, 309, 310 

with benzenearsonic acid 77 

with brucine 107 

by cellulose chromatography 40, 306, 310 

by chlorination with octachloropropane 

1lli 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 71 

Separation of niobium from tantalum-Con. 

with cinchonine 106 

by crystallization 38 

by distillation 160 

by extraction of fluoride 306, 310 

with ferroin and HF 89 

by fractional crystallization of double 

fluoride 206 

by halogenation 150 

by H202 • H2S04 123 

by hydrolysis of fluoride 313 

by ion exchange 146 

by Marignac method ~8 

with methyldioctylamine in xylene lfi6 

with KIO:• 294 

by precipitation of K.Ta.,Q~F.. ~I~ 

by reduction of NbCb 221 

with sodium hypophosphite 

by solvent extraction 31 0 

by strychnine 107 

with tannic acid 17 

with tannin 102, lOll, 196, 196a, 290, 308, 

309 

Silicic acid 213 

Silicon (Si) 79, 93, 97, 109. 130, 186, 187, 

278, 295, 307 

Silver (Ag) 51, 162, 168 

Sodium (Na) 72 

Sodium hypophosphite 5 

Soevite 154 

Solvent extraction 175. ~~ 0 

Spectral nnalysis 23, 64, 66, 122 

Spectrochemical analysis 88 

Spectrography 3~. 68, 88. 1 0.{, 110, 122. 140, 

168, 204, 228 

Spectrophotometry 84 

Spectroscopy 26. M. 71. 109 

Spectrum tables 36 

Stainless steel 26, 66, 127, 191 

Steel 11, 15. 16. 39, 47, 67, 88. 114, 1.2::1. 1~3. 

134. 141, 146. 186. 186, 19~. 205, 22::1, 

280. 286, 301, 307 

Steel analysi~;~ 15, 16 

Steeloscope 71 

Strontium (Sr) 29, ~0. 31, 61, ::10~ 

Strychnine 1 06 

Substituted acids 299 

Succinic acid 56 

Sulfur 186, 187, 278 

Tannic acid 17, 168 

Tannin 21, 42, 43, 48, fiO, 66. 93. 102, 106, 

106, 107, 108, 112, lli4, 196, 196a, 19'6b. 

224, 226. 228, 229. 231. 233. 236. 237, 

238, 242, 248, 246. 247a. 263, 264, 266. 

256. 258. 264. 290. 297, ao5. ao8. ~09. 

:no Tantalic acid 211 

TantRiite 68, 230, 254, 264 

Tantalocolumbates. See Tantaboniobates 

Tantalocolumbite 176 

Tantalaniobates 1, 50, 240 

Tantalum 15, 31, 58, 72, 182 

acidimetry 277 

action of SOCh on Ta20a 93 

Tantalum-Continued 

activation assaying 65 

alloys 209 

analysis 288, 286 

analytical chemistry 13, 116, 197, 211, 

214, 217, 218, 220, 221. 222, 226-

259, 290, 301 

analytical methods 201, 203, 227, 229, 259 

anion exchange studies 144, 145 

aromatic arsenic compounds 194 

betainelike complex salts 184 

bibliography 124, 186 

in black sands 317 

in carbide composition 204 

in cassiterite 28. 192 

in cast iron 278 

cellulose chromatography 165, 306, 310 

in cemented carbide compounds 288 . 

chelate compounds 161 

chemical enrichment 201 

chemical properties 209 

chemistry 178, 214, 217. 220. 221. 222 

chlorination 13, 115, 291 

chlorination with octachloropropane ll!l 

color reactions 61, 129, 161, 210, 266 

with polyphenols 129 

with arsono acids 151 

colorimetric tests 129, lfi3, 262, 26~ 

with aminobenzenearsonic acid 16~ 

with gallic acid 129 

with 2-furaldehyde 163 

with polyphenols 129 

with pyrocatechol 129 

with pyrogallol 129 

in columbite 264, 264, 291 

complex fluoride compounds 21.2, 213 

complex with tartaric acid 240 

concentration with organic reagE'nt.q !l4 

critical review 13 

detection 212, 213, 317 

in eudialytes 29 

in metals, minerals, and rock!' 6 

with tannin 196, 196a 

in zircon 29 

determination in Nb by X-ray fluorescence 

23, 24 

tiistillation 13, 116 

in drug ash 207 

electrodeposition 117 

electrolysis in phosphate melts 103 

electrolytic preparation 72 

elemental analysis by flame photometry 

86 

in euxenite 291 

extraction 94, 118 

with CHCh of organic complexes 94 

of fluoride 40, 166, 170, 305, 306, 310 

with methyl ethyl ketone Hi6, 170. 

306, 306, 310 

in ferrous alloys 280 

film reaction 176 

fractionation of Ta20a 32 

geochemistry 73, 201, 202 

halides 70 

halogenation 93, 214, 217, 220, 221, 291 
72 SELECTED BIBLIOGRAPHIES OF ANALYTICAL CHEMISTRY 

Tantalum-Continued 

high-temperature structure 63 

hydrolysis 101 

ignition temperature of tannin complex 

108 

infrared spectroscopy 56 

inner-complex salts 299 

interference of W in determination 239 

in loparite 3, 43, 297 

metal from tantalic acid 211 

metallurgy 173 

in meteorites 201 

methods of separation 132 

microanalysis 182 

in minerals 201, 222, 224, 230, 231, 306. 

310 

Nb in powdered Ta 168 

Noyes and Bray system 169 

occurrence 201 

in ores 201. 286, 306, 310 

organic complexes 94, 101. 108, 129, tfit. 

163, 240, 299 

organic derivative with glycol 299 

organic reagents 94, 129, 151, 163, 199, 

278 

organometallic compounds 2 

past history 267 

in perovskite 167 

pH of precipitation 131 

photometric determination 11 

physical properties 209 

polarography 316 

precipitation, with benzenearsonic acid 

6, 7 

formaldehyde 

morin 283 

phenols 4 

quercetin 283 

sodium compounds 235 

sodium hypophosphite 5 

tannin 290, 297, 308, 309, 310 

·precipitation from tartrate solution 250, 

251 

procedures for determination 301 

properties 311 

purification of preparations 214, 221 

pyrolysis curves 60 

qualitative chemical test in foundry materials 187 

qualitative reaction with pyrogallol 189 

qualitative reaction with · resorcinol 189 

quantitative reactions 318 

in rare-earth minerals 206 

reaction, with aldehydes 299 

aliphatic amines 299 

aromatic amines 299 

cacotheline 303 

esters 299 

gentian violet 262 

hydroquinone 266 

iodine 303 

ketones 299 

methylene blue 262 

organic reagents 190, 262, 263, 266, 

280, 299, 303 

Tantalum-Continued 

reaction, with_:_Continuerl 

oxalic acid 303 

phenols 299 

pi~olines 299 

pyrocatechol 262 

pyrogallol 266, 280, 303 

quinalizarin 303 

resorcinol 263, 318 

rhodamine B 2'62 

selenious acid 258 

substituted acid 299 

reagents 87, 303 

reduction with dropping mercury cathorle 

316 

reduction of oxide with CaH2 166 

reduction of Ta3+ 67 

references 302 

reviews, of analytical chemistry 47 

of 1936 developments 72 

of 1940 developments 125 

of estimation 281 

of literature 173 

of papers (1933-40) 302 

of patents (1933-40) 302 

in rocks 201 

in ruby sands 317 

semimicro analysis 169 

sensitive reactions 262 

in slags 13, 218 

in soevite 280 

solubility, in carbon disulfide 154 

in CC14 176 

in CHCb 175 

in ethyl bromide 175 

in ethylenediamine 175 

in nitrobenzene 175 

TaBr5 in organic solvent.'! 175 

solvent extraction 306, 310 

sources 209 

spectra 64, 80 

spectral analysis 54, 223 

spectrochemical analysis 68 

spectrum 80, 136 

in stainless steel 56, 191 

standard tests 162 

in steel 11', 146, 280, 286, 301 

sublimation 214, 217, 220, 221 

Summary of analytical methods 254 

in synthetic materials 306 

in tantalite 264 

in tantalocolumbates. See tantaloniobate~. 

in tantalocolumbite 176 

in tantaloniobates 50, 239 

tartrate hydrolysis 256 

tartarotantalates 270 

test as per acid 139 

thermal expansion 63 

Ti in powdered Ta 157 

Tre~tment of Nb-Ta materials 269 

in Uranium ore 316 

uses 257, 311 

X-ray spectra 298 

X-ray spectral analysis 30, 31 

in wolframite 48 
NIOBIUM AND TANTALUM, JANUARY 1935-JUNE, 1953 73 

Tantalum pentabromide 175 

'L'antalum pentachloride 175, 214-222 

'l'antulum pentafluoride 40, 41, 70, 306, 310 

Tu-Pt electrodes 277 

Ta-'l'u~o~ electrodes 277 

Tantalum pentoxide 3, 4, 8, 9, 10, 16, 17, 18, 

38, 43, 44, 56, 60, 93, 97, 102, 123, 141, 

146, 147, 157, 180, 188, 208, 214, 216, 

217, 220, 297, 305, 308, 809, 310, 315 

Tantalum phosphate 99 

'fa • Pt electrodes 277 

Tantalum silicates 29 

'l'a • Tn~05 electrodes 277 

'fartaric acid 10, 60, 240, 250, 251, 

1'artrate hydt·olysis 250, 251, 256 

Tellurium (Te) 72, 186, 187 

Terbium (Tb) 231 

Thallium ( Tl) 302 

1'hermobalance 130 

'l'hermogravimetry 59, 60, 130 

Thionalide 94 

Thionyl chloride 93 

272 

Tungsten-Continued 

determination in earth-acid minerals 250 

precipitation by tannin 233 

precipitation by tannin • cinchonine 236 

in steel 39 

Tungsten carbide 69, 79 

Tungsten group 169 

Uranium (U) 30, 31, 46, 49, 50, 72, 90, 93, 

125, 140, 151, 152, 153, 162, 168, 187. 

207. 253, 255, 256, 263, 302, 303 

Uranium-niobium alloys 170 

Uranium-tantalum alloys 170 

Urotropine 107 

Vanadic acid 168 

Vanadium (V) 20, 46, 49, 50, 51, 55, 88, 93, 

109, 162, 187, 207, 256, 262, 278, 292, 

302, 307, 316 

Vandium pentoxide 46, 166 

reduction with CaHz 166 

Vapor pressures 70 

Volatilization 214, 217, 219, 220, 221, 266 

Volumetric methods, discussion 44 

'l'horium (Th) 29, 30, 31, 72, 80, 90, 93, 

140, 151, 152, 158, 162, 182, 256, 

263, 294, 299, 802, 308, 31 '1 

Wolfram (W). See Tungsten 130• Wolframite 1, 48 

Tin (Sn) 20, 97, 151, 153, 187, 192, 207, 

217. 220, 262, 278, 802 • 

determination in niobates 261 

determination in metallic Nb 261 

256, 

214, 

Titanium ( Ti) 6, 8, 14, 16, 20, 33, 42, 44, 49, 

60, 61, 68, 71, 72, 79, 88, 90, 93, 97' 

109, 126, 133, 134, 136, 148, 149, 151, 

152, 153, 162, 168, 180, 182, 187, 188, 

192, 196b, 204, 206, 213, 214, 217, 220, 

226, 231, 237. 238, 243, 246, 253, 258, 

262, 276, 278, 280, 283, 286, 286, 289, 

292, 304, 307 0 316, 317 

TiO~. reduction with CaH2 166 

Tungsten (W) 20, 31, 46, 68, 72, 79, 109, 126, 

127, 140, 162, 163, 182, 187, 192, 204, 

206, 233, 236, 239, 262, 278, 307, 317 

decomposition with H2SO~ 

X-ray diffraction 63 

X-ray fluorescence 23, 24, 51 

X-ray spectra 27, 298 

X-ray spectral analysis 30, 31 

X-ray spectroscopy 29, 30, 31 

Xylene 156 

Yttrium (Y) 29, 61, 80, 93, 99, 125 •. 231, 303 

Zeeman effect 136 

Zinc (Zn) 30, 51, 93, 187, 302 

Zirconium (Zr) 6, 8, 14, 16, 29, 30, 31, 49, 

61, 71, 72. 80, 88, 90, 120, 121, 122, 

126, 130, 140, 151, 162, 153, 162, 174, 

180, 187. 192, 196b, 213, 226, 231, 241, 

245, 247a, 256, 266, 263, 278, 294, 299, 

302, 317 

:l.irconium silicate 29 

Zircons 29 

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