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Talanta 1958 V1 No4 Nov.Pdf 296 JAMES B. HEADRIDGE Apparatus A commercial spectrophotometer is quickly adapted for photometric titrations. For example, Hunter and Miller8 have modified the Unicam SP 500 and Bricker and Sweetser9have converteq the Beckman DU for titrations. REVIEW OF RECENT WORK Apparatus Maher10 has discussed the development ofautomatic photometric titrimeters. The Beckman Model B spectrophotometer has been modified· for automatic titrations.ll An instrument for automatic derivative spectrophotometric titrations has been described,12 and Chalmers and Walley13 have constructed a recording titrimeter. Stolyarov14 has described an apparatus for titrations in ultra-violet light where a filter with maximum transmission at 365 m,u is used. Details have been given for the modification of the Beckman DU spectrophotometer for titrations.15 Wallraf16 has constructed a filter photometer for the titration of calcium and magnesium with ethylenediaminetetra-acetate. Review articles and theoretical considerations Goddu and Hume2 have discussed the principles of the photometric titration method and have reviewed previous work in the field up to the end of 1953. Underwood17 has described the advantages of photometric titrations and the applica­ tion of the method to acid-base, oxidation-reduction, turbidimetric and complexo­ metric reactions. Grunwald18 has reported a method for accurate end-point determination in photo­ metric titrations where the titration curves are rounded in the vicinity of the end­ point. Class I titrations Acid-base: Goddu and Hume19 have studied the photometric titration of a weak acid (or base) with a strong base (or acid) and have shown that a sharp inflexion ofthe graph of optical density plotted against volume of titrant is obtained only when the product of ionization constant and molarity of the weak component, is ::> 10-12 at concentrations of 10-5M and above. Telluric acid has been satisfactorily titrated with aqueous ammonia at 240-280 m,u.20 In glacial acetic acid, quinoline, o-chloroaniline, m-chloraniline and sodium acetate have been titrated photometrically with acetous perchloric acid. 21 Photometric titrations in non-aqueous solvents have so far received little attention. Further investigations in this field could be profitably undertaken. Oxidation-reduction: Cerous ions in the presence oflarge amounts of ceric ions in neutral pyrophosphate medium have been determined with permanganate.22 Cerium, in bismuth-base alloys, can be determined by the titration of the ceriumIII in pyro­ phosphate medium with permanganate in the E.E.L. absorptiometer.23 Deshmukh and Bapat24 have titrated thiourea quantitatively in hydrochloric acid­ bromide solutions with potassium iodate solution, using a Hilger Spekker absorptio­ meter for photometric end-point detection. Sweetser25 has titrated arseniclII with ceriumIV at 320 m,u and, ironII and uraniumIV 394 L. ERDEY, I. BuzAs und K. VIGH TABELLE IX.-TITRATION VON VERSCHIEDENEN SILBERNITRATLOSUNGSMENGEN MIT' KALIUMJODIDLOSUNG IN ANWESENHEIT VON VARIAMINBLAUACETAT ALS INDICATOR In 0,1 n Losungen In 0,01 n Losungen Einwaage 0,1 n, 0,01 n Verbrauch Abwei- Verbrauch an Abwei- AgN03 Mittelwert Mittelwert anKJ ml ml chung KJ ml chung ml % ml % 4,92 5,06 4,95 4,94 4,93 -0,40 5,25 5,16 +4,2 4,92 5,17 9,84 10,26 9,86 9,83 9,84 -0,20 10,31 10,23 +3,8 9,84 10,13 19,63 19,91 19,64 19,66 19,64 ±O,O 20,16 20,04 +2,0 19,63 20,06 29,34 30,12 29,43 29,35 29,34 -0,31 30,39 30,25 +2,8 29,33 30,25 48,88 49,77 49,01 48,90 48,89 -0,25 50,56 50,19 +2,4 48,90 50,24 durch 5 minutiges Schiitteln mit 0,5 g Aluminiumhydroxyd oder Aluminiumoxyd und filtriert. 1 ml der Losung ist zur Fiillung von 3,5 mg Kalium geeignet. Es ist zweckmiissig die Losung stets frisch zu bereiten. Waschfliissigkeit: 0,1 g des na,.h obiger Vorschrift gefiillten und mit Wasser ausgewaschenen Kaliumtetraphenylboratniederschlages wird mit 250 ml Wasser wiihrend 30 Minuten geschiittelt, zur triiben Losung dann 0,5-1 g Aluminiumhydroxyd oder Aluminiumoxyd gesetzt, einige Minuten hindurch umriihrt, filtriert und die ersten 20 ml des Filtrats neuerdings auf das Filterpapier gegossen. Die Waschfliissigkeit muss vollstiindig klar sein. Verfahren: Die 10-100 mg Kalium enthaltende Losung verdiinnt man auf 100 mI, siiuert mit n Essigsiiure gegen Lakmus eben an, dann setzt man zur Losung in ungefiihr 1,5-fachen Dberschuss tropfenweise die 0,1 n Natriumtetraphenylboratlosung zu, filtriert in 5 Minuten durch ein dichtes Filterpapier und wiischt dann den Niederschlag mit der Waschfliissigkeit solange bis das Filtrat mit Silbemitrat schon kaum eine Reaktion zeigt. Das Filterpapier gibt man samt Niederschlag in das Glas, wo die Fiillung erfolgte, zuriick, giesst es mit 10-20 mI Aceton auf und lOst den Niederschlag unter Umriihren mit einem Glasstab. Die acetonige Losung siiuert man mit 2 mI n Essigsiiure an, fiigt 3 Tropfen Variaminblaulosung hinzu und titriert mit der Silbernitratmasslosung bis zum Erscheinen der violetten Farbe. Gegen Ende der Titration titriert man tropfenweise und schiittelt nach jedem Tropfen kriiftig urn. 1 ml 0,1 n Silbemitratlosung entspricht 3,9096 mg Kalium. TALANTA An International Journal of Analytical Chemistry VOLUME 1 1958 Editor-in-chief C. L. WILSON Belfast, N. Ireland v Regional Editors L. GORDON R. PRIBIL T. TAKAHASm Cleveland Prague Tokyo Editorial Advisory Board Professor F. E. BEAMISH-Toronto Professor W. WAYNE MEINKE-Ann Arbor, Dr. R. BELCHER-Birmingham (Chairman Michigan ofthe Boar;!) Dr. J. MINCZEWSKI-Warsaw Professor H. BoDE-Hanover Dr. A. D. MITCHELL-London Professor G. CHARLoT-Paris Dr. G. H. MORRIsoN-Bayside, New York Professor C. aMERMAN-Haifa Professor F. NYDAHL-Uppsala Dr. C. E. CROUTHAMEL-Argonne, Illinois Dr. E. RANCKE-MADSEN-Copenhagen Profess.or P. DELAHAy-Baton Rouge, Professor G. GOPALA RAo-Waltair, S. India Louisiana Professor C. N. REILLEY-Chapel Hill, N. Professor H. DIEHL-Ames, Iowa Carolina Dr. C. DRAGULESCU-Timisoara Dr. M. L. SALUTSKY-Baltimore, Maryland Professor L. ERDEY-Budapest Professor G. SEMERANo--Padova Professor F. FEIGL-Rio de Janeiro Professor E. SCHULEK-Budapest Dr. H. FLASCHKA-Atlanta, Georgia Professor G. FREDERICK SMITH-Urbana, Illinois Professor W. GEILMANN-Mainz Dr. T. B. SMITH-Sheffield Dr. J. HosTE-Ghent Professor H. SPEcKER-Dortmund-Aplerbeck Mr. H. W. KIRBY-Miamisburg, Ohio Professor E. H. SWIFT-Pasadena, California Professor J. J. LINGANE-eambridge, Professor P. S. TUTUNDzIc-Belgrade Massachusetts Professor F. L. WARREN-Pietermaritzburg Professor F. LUCENA-CoNDE-Salamanca Dr. H. WEIsz-Vienna Dr. S. J. LYLE-Durham Dr. T. S. WEST-Birmingham Dr. R. J. MAGEE-Belfast Dr. JAMES C. WmTE-Oak Ridge, Tennessee Dr. H. MALIssA-Diisseldorf Professor H. H. WILLARD-Ann Arbor, Michigan Mr. F. J. WOODMAN-Sellafield PERGAMON PRESS NEW YORK . LONDON . PARIS . LOS ANGELES Colorimetric detection of iron with cacotheline . 169 - determination of iron with cacotheline . 169 - - - - in metallic copper with 4:7-diphenyl-1 :lO-phenanthro1ine 76 - - - zirconium with pyrocatechol violet 263 Complexometric titration of aluminium in the presence of interfering ions 314 - - - calcium in the presence of magnesium . 238 - -, Theory of visual indication and selectivity 60 Copper, Determination by extraction as pyridinohalide complex 55 -- of traces of iron in 76 -, Potentiometric titration with triethylenetetramine . 127 Coulometric titration of dyestuffs with electrolytically generated dithionite 110 Cyanide, Titrimetric determination with Variamine Blue as indicator 377 Detection of cobalt. 88 - -iron with cacotheline 169 Determination of aluminium by complexometric titration 314 - - aromatic compounds with bromine monochloride 244 - - cadmium by potentiometric titration with triethylenetetramine 127 - - calcium complexometrically 238 - - - by titration with 1:2-diaminopropane-N :N'-tetra-acetic acid 242 - - cobalt . 88 - -- by extraction 249 -- copper by extraction 55 - - -- potentiometric titration with triethylenetetramine 127 - - cyanide argentometrically with Variamine Blue as indicator 377 - - dyestuffs by coulometric titration 110 - - ferricyanide by titration with mercurous thiocyanate system 305 - - gold by potentiometric titration with ascorbic acid 159 - - halides argentometrically with Variamine Blue as indicator 377 - - hydrazine and hydrazine derivatives titrimetrically with bromine monochloride 344 - - indigo carmine by coulometric titration with electrolytically generated dithionite 110 - - iron colorimetrically with cacotheline 169 - - mercuric chloride titrimetrically 184 -- mercury by potentiometric titration with triethylenetetramine 127 - - metal ions by potentiometric titration with triethylenetetramine 127 - - metals in organic compounds . 408 - - methylene blue by coulometric titration with electrolytically generated dithionite 110 • - - nickel by extraction 249 - - niobium spectrophotometrically by 8-hydroxyquinoline 329 -- osmium gravimetrically by I :2:3-benzotriazole . 351 - - phenylhydrazine titrimetrically with bromine monochloride. 344 - - phenols titrimetrically with bromine monochloride 224 - - phosphorus in organic compounds 185 - - platinum metals, gravimetrically 3 - - polymers by a cloud point method 105 - - potassium argentometrically with Variamine Blue as indicator 377 - - semicarbazide titrimetrically with bromine monochloride 344 - - sulphur by 4-amino-4'-chlorodiphenyl 142 - - - - amperometric titration 276 - - sulphuric acid content spectrophotometrically. .. 374 - - tantalum spectrophotometrically with 8-hydroxyquinoline I. 329 -- thiocyanate argentometrically
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