(191) Schnabe, K., Suschke, H. D., Angew. (209) Spiro, l1., Electrochim. ilcta 9, Chenz. 76, 39 (1964). 1531 11964). (192) Schwing, J. P.,J . Chim. Phys. 61, (210) Steed, K. C.,Fransman, F., Anal. 491 Chim. Acta 32, 472 (1965). ~-~ 11964). (193) Sciboi;a, G.,Scuppa, B., J . Phys. (211) Stenina, N . I., Agasyan, P. K., Chem. 68, 2003 (1964). Zh. Analit. Khim. 20, 351 (1965). ( 194) Shams-El-lXn, A. M.,El-Hosary, (212) Stephen, W. I., Znd. Chemist 39, A. A , , J . Electroanal. Cheni. 8 , 139 321 (1963). 11964). (213) Stokes, R. H.,Australian J . Chem. (lis) Shams-El-Din, A. ?+I., El-Hosary, 16, 759 (1963). A. A. A,, Gerges, A . A , , Ibid., p. 312. (214) Strafelda, F.,Collection Czech. Chem. ( 196) Shams-El-Din, A. AI., El-Hosary, Conznmn. 28, 3343 (1963). A. ii., Zbid., 9, 349 (1965). (215) Ibid., 30, 2320 (1965). (197) Shams-El-lXn, A. >I., Gerges, A . 1216) Strafelda. F..Karlik., 11.. , hlatonsek. A . A4., Electrochinz. Acta 9 , 123 (1964). J., Ibicl., p. 2327: (198)Ibid., p. 613. (217)Zbid., p. 2334. (199) Sher\vood, P., S.H. Thesis, Mass. (218) Strafelda, F., Dolezal, J.. Chem. Institiite of Technology, 1964. Listy 58, 17 (1964). (200) Shiratori, H., J . Electrochem. SOC. (219) Stein, G., J . Chem. P h p . 42, 2986 Japan, Ouerseas Ed., 29, El61 (1961). (1966). (220) Stern, K. H., Stiff, J. A,, J . Elec(2Olj Shivahare, G. C., Satztrwissentrochem. SOC.1 1 1 , 893 (1964). schajten 52, 157 (1965). (202) Short, G. 11.) Bishop, E., 4 ~ ~ 1 , . (221) Su, Yu-Sheng, Hsueh, H., Tung Pao X O . 10, 620 (1964). CHEM.37, 962 (1965). (222) Suchomelova, L.,Horak, V.,Zyka, (203) Shpeizer, G. l L j Zaidman, N. AI., J., dficrcchem. J . 9, 201 (1965). Zavodskaya L a b . 31, 272 (1965). J. Liiedenbach, (223) Suschke, If. (204) Shvaika, 0.P.,llnatsakanova, T. Z. Chem. 4 , 61 (1964). R., Aleksandrova, 11. &I.,Zh. Analit. Khim. 20, 273 (1‘365). (224) Swofford, H. S., Jr., ANAL.CHERT. 37, 610 (1965). (205) Singh, B., Verma, B. C., Kalia, Y. K., Indian J . Chem. 2, 124 (1964). (225) Tacussel, J., Bull. SOC. Chinz. France 1964, 1155. (206) Sherlak, T., lIilicevic, V.,Glasnik Drustzia Hemicartr Technol. S. R. Bosne (226) Takahashi, T., Sakurai, Kogyo Hercegovine S o . 1 1 , 49 (1962). Kagaku Zasshi 67, 1802 (1964). (207) Slevogt, K., TVirth, H., Z. Instric(227) Talipov, Sh. T.,Podgoriiova, T’. S., mentk. 72, 72 (1964). Uzbeksk. Khim. Zh. 8 , 26 (1964). (208) Smith, U. W., Instr. Eng. 4, 7 (228) Tanaka, V., Tamamushi, It., Elec(1964). trochim. Acta 9, 963 (1964). \
-
-
-
-
(229) Taroiyanta, Tr., M o s k . Khzm.Technol. Znst. 1963, 149, (230) Tien, H. T., AXAI,. CHEV. 36, 929 (1964). (231) Tockstein, A,, Z. Chetnze 5 , 255 (196.5). (232) Trmidell, A. IT., ZSA Proc. AYatl. -1nal. Inst. Symp. 8 , 67 (1062). (233) Tsiitsiimi, K., Bunseki Kagaku 13, 1126 (1964). (234) Cgol’nikov, X . il., Sholokhova, Z. P.. T I . Tomskaao. Gos. C’niv.. Ser Khzm. 154, 267 (1982) 1235) Uhniat. AI.. Zanada. T.. Chznz. Anal (Wa;saw) ’9, 701 (1964).’ (236) \.ecerek, B., Cibiilec, 4., Cheni. Lzsty 58, 1153 (1964). (237) Vitiikhnovskava, B. S.. l’r, Dnevrowetr. X e t . Znst. A\-o. 44. 201 (1061): (238) T’orob’ev, I. ?\I., Tr. Len2nqI. Tekhnol. Inst ~sellynlozn.-Bumazhn. Prom. o. 10, 65 (1O62). (239) JT’aligora, B., PaluLh, Cheni. Anal. ( W a r s a u ) 9, 23!) (1964). (240) Wegmaiin, I)., Simon, TV , H e l c . Chznz. Acta 47, 1181 (1964). (1‘ - ’ ‘ (241) Yan, J F., F., . 4~>>IILL. . CHERI. 37, ljS8 A\
ilYfi.5)
(242) -Z;goraki,
K., .Inn. CnzL. J Z a , me Curze-Sklodowska, Lubzn-Polonza L e d . A A , 17, 159 (1962). 1243) Zaidman. ?;. 31.. ShneiAer. G. 11.. Podriigina, E . P., d S d l i ‘ Pateirt 160,357, (Jan. 16, 1964). (244) Zyka, J., R u d u (Pragiie) 12, 177 (1964). (245) Zyka, J., alngezc. Cheinze 4 ( 7 ) 602 (1965).
Volumetric and Gravimetric Analytical Methods for Inorganic Compounds W . H. McCurdy, I r . , University o f Delaware, Newark, Del., and D. Schenectady, N . Y.
A
to the recent statistical survey of trends in analytical chemistry (%A), research papers on gravimetric and titrimetric analysis have decreased by 50y0 based on the total analytical publications in 1955 and 1905. I n support of these result., the present authors have observed that the number of articles dealing with inorganic “wet-chemical” methods has remained virtually constant over the past sir years while the total volume of published material has doubled. The established procedure of publishing any given method in an endless variety of niodificaticns places increasing responsibility upon the analytical chemist t o recognize fundamental advantages of one method compared to another. For this reason, a number of the literature references selected may appear to have little direct application to chemical analysis. Efforts have been made to direct attention to those areas where thearetical principles were uncovered, original approaches developed, or important sources of error revealed during the reporting period, January 1964 to CCORDING
H.
Wilkins, General Electric Research laboratory,
December 1965. A\.lpologies are made in advance for many worthwhile contributions which may have been overlooked because of the use of abstracts \Then original literature was not available. SIGNIFICANT TRENDS
Through the J ears, rather unselective organic precipitants have been utilized to advantage in solvent extraction procedures. It is expected that evaluation of structural features influencing chelate formation will aid in the development of valuable reaqents for a variety of analytical methods. Burger et al. ( 1 2 9 , I&4) have esaniined the infrared and ultraviolet spectra of 5-methyl-, 5chloro-, and 5-nitrosalicylaldoxime~and manganese(I1) iron(T1) nickel(I1) , copper(II), and zinc(1I) chelates. Substituent effects are attributed to changing charge density of the donor atom coordinate u bond and A acceptor capability of the ligand (back bonding). Thus ligand field stabilization effects produced increased rather than de~
~
creased coinples stability in the 5methyl- to 5-nitrosalicylaldosinie series. The observation of nearly equal stepwise formation constants wa? attributed to strong intramolecular hydrogen bonding which stabilizes the bi dosime chelate. AIeasurenients of shifts in carbonyl and thiocarbonyl stretch frequencies in 8-quinolinol and 8-mercaptoquinoline chelates of palladium(II), nickel(lI), and cadmium(I1) were interpreted by Dalziel and I I. Evaluation of intrinsic solubility (Soj of several zinc., c o h l t , and copper 8-quinolinolates by Fresco and Freiser (%A) showed a decrease in So value with decreasing metal ion radius and increasing size of alkyl substituent. Singh and Sharnia (105A) have continued earlier studies with 2-hydrosymethylacetophenosinies. The 5metbyl derivative niay be used for selective separation of copper a t pH 2 and nickel a t pH 4.5 from a number of related metalq. Ai summary of s o h bilities and equilibrium constants of inetal dioxiiiie chelates was published by Dvrssen (32A). A study of the solubiiity and stabilit,y of 11 metal chelates with 2-amino-1,3,4-thiadiazole-5-thiol by Domagalina and Przyboromki (31-4) is representative of general iiiterest in sulfur ligands. Additional selectivity was obtained with masking agents. Walton (114-4) has sunimarized recent contributions to iiucleation theory in a review, He suggests that, particles of silica act as catalysts for nucleation in most precipitation reactions. -11though critical supersat,uration vayied wit,h method oE solution filtration, Haberman and Gordon (43.4) obtained an estimate of 5 ions in the critical nucleus of lead chromate precipitated from homogeneous solution. I n order to study homogeneous rather than heterogeneous nucleation of bariuni sulfate, Klein and Fontal (6UA) removed the first portion of precipitate by filtration. Sulfate was generated by electrocheinical oxidation of thiocyanate. The niaxiniuni rate of homogeneous nucleation was found to lag considerably behind the maximum critical supersaturation. Vasil6v and Sitko (113A) applied ultrasonic stirring to accelerate precipitation of bariuni sulfate, calcium oxalate, and niagnesiiini animoniuni phosphate. Quantitative precipitation was obtained in 5 minutes. S e w concepts of electron transfer in solution have gained support by study of inetal chelate reactions. Campion, Purdie and Sutin (15-4) report faster rates of oxidation of mixed ligand complexes such as dicyanobis-1,lO-phenanthroline iron (I I) than either tris-1 ,1O-phenanthroline iron(I1) or hesacyanoferrate (11). The effect is explained by assuming t'hat the slower electron exchange 470 R
ANALYTICAL CHEMISTRY
rate of the mixed ligand complex is cffset by a more favorable reaction equilibrium constant. Dicyanohis-1,lOphenanthroline iron(I1) has been allplied as reversible indicator in titration nf azide and sulfaniic acid with nitrite by Schilt and Sutherland (,99A). Candlin and Halpern (16A) proposed nieasurement of activation volumes to distinguish between inner and outer sphere electron transfer mechanisms. The inner ,sphere iiiechanism usually involves a bridged intermediate and liberation of coordinated water. Coordinated water is not' displaced in the outer Sphere process, which therefore requires a smaller activation volume because of the snialler size of coordinated water. Reaction rate by the inner sphere path may be lo5 times faster than the corresponding outer sphere rate. Reaction of Shydroxyethyl(ethylenedinitri1o)triacetatocobaltate(II1) with iron(I1) has heen described by Wood and Higginson (117A) as an inner ?!)here mechanism. The bridged intermediate uiidergoes electron transfer to yield the c o l d t ( I 1 ) coniples, which rearranges to form cobalt (11) and ,V-hydroxyet hy1(ethylenedinitrilo)triacetatoferrate(III). The esistencr of chloro or hydroxo bridging markedly increased the rate of the correspondins reaction \Tith (ethylenedinitrilo)tetraacetatocobaltate(III) oxidant. An unusual sequence of reactions is proposed by Norkus (84d) to esplain acceleration of the very slow reaction of chlorite with iodide in the presence of o m i c acid catalyst when arsenite is added. The catalyst is reduced by arsenite which reduces chlorite to hypochlorite; hypochlorite oxidizes iodide to iodine which i q titrated with arsenite. The determination is quantitative in bicarbonate media. Holconib (48-4) reports the first analytical application of sodium persenate. Quantitative oxidation of aniericiuni(II1) t o (VI) was obtained in 30 seconds using silver(1j nitrate as catalyst. A recent review by Gillard and Irving (38x1) presents a good discussion of conformational aspects of chelate forniat'ion. Evidence from x-ray and NMR prove that ethylenediamine is in a puckered or gauche form in met'al chelate structures. Day and Keilley (30-4) utilized the presence and absence of different types of N l I R splitting patterns to determine the lability of 0inetal and ?;-metal bonds in various chelates. In subsequent papers, Sudelucidated the meier and Reilley (106-4) protonation scheme of several polyaminocarbosylic acids from chemical shift data as a function of pH. Further understanding of the difference in rates of wrapping and unwrapping equatorial us. axial cmforniational structures may be expected in the near future. Enthalpy and entropy data for inetal
chelate reactions provide considerable insight into structural effects. Ande(44) and Staveley et nl. (SSil, 5JA) ss thermodynamic results for alkaline esrths, rare earths, and many transition metals with iiitrilotriacetic acid (XTA). The reaction enthalpy is found t o be sinal1 and invariant with different elements when compared to the entropy term. A1nderegg (5Aj also nieazured formation constants and heats ofrea ction of 3everal dinitrilo tctraacetate ligands n-ith metals where the number of methylene g r o u p separating nitrogen? was increased from 2 to 4. I n one grouli of metals 130th formation ccnstant and enthalpy decreased as the separation between nitrcgens increased; in another group, the formation constant decreased while enthalpy increased slightly. Heats and entropies of variow polyamine and polyarninocarboxylate chelates were compared with earlier results of -4nderegg on (ethylenedinitri1o)tetraacetate (EDTA) chelat'es by M'right, Holloivay, and Reilley (1 18.4). I n general, the entropy increase obtained in the diqilacement of water from the metal ion and ligand is found to be the main driving force which proniotes chelate formation. The magnitude of this effect n-as denionstrated by Hseu, F u , and Chuarig (52~1) in a study of theriiiodyna,inic constants for the formation of tmns-l,2-dianiinocyclohexane - A17JT,AV',aY' - tetraacetate (DCT.\) chelates of mercury, zir(-onium, and thorium. The entropy increase on chelation of thorium is nearly double the value for mercury, while the formation constants are identical for these compounds. The coordination kinetics of stepwise replacenlent of one ligand by another are described by Rorabacker and hlargerum (94.4). The rate-deterinining step involves replacenient of m t e r followed by Y-metal ?)orid forinat'ion with the attacking ligand. The inverse situation where EDTA is transferred from one nietal to another has also been studied by Slargeruni et al. (73A). I n this case, formation of the half wrapped-half unwrapped hinuclear intermediate is believed to control the rate. X a n y of these factors have obvious application to chelonietric tit'rations. Crisan and Liteanu j2oA4)note that a light green intermediate formed on addition of sodium acetate t o acid chromium(IJ.1) nitrate reacts rapidly with EDTA. If the buffered solution is allon-ed to stand several minutes before addition of EDTA\, essentially no reaction occurs. The iniportaiice of boiling with 5.17 sulfuric acid to decompose polynuclear zirconium species prior t,o EDT.1 titration was stressed by Pilkington and Wilson ( $ 0 3 ) . Other coinrnon acids are not suitable. Formation of mixed hydroso-EDT.\ complexes of antimony and bismuth at low pH is
discussed by Bhat and Iyer (11A). Yaguchi and Kajiwara (119A) discovered a change in coordination of molybdenum with EDTA on changing the reduct,ant for molybdate. -4 2 to 1 molybdenum(V) EDTA complex formed using hydrazine sulfate is altered to the more desirable 1 to 1 complex by reduction with hydroxylamine chloride. Olsen (MA) suggested preparat,ion of magnesium EDT-4 on Dower; 1 anion exchange resin as a suitable reagent for substitution titration of calcium and strontium. Although a zinc substitution titration was not entirely successful by this method, other ion exchange resins and resin chelates may be worthy of study. Copper(I1) forms a green 1 to 1 chelate with 1,1,2,2-tetrakis (carbosyniethy1thio)ethane which Longo et al. (70A) utilized in a photometric titration. Other structure modifications of this sulfur analog of EDTA should prove interesting.
GRAVIMETRIC ANALYSIS
Precipitation from Homogeneous Solution. Precipitation of hydrous aluminum oxide by slow decomposition of ethylene chlorohydrin in hot alkaline solution was reported by Vzumasa et a!. (1f1A). The easily filtered precipitate formed hy this method suffers far less anion interference than urea hydrolysis in acid solution. Irving (54A) favors the basic benzoate over the basic succinate PFHS method because of greater ease of filtration of the benzoate salt. Neither method permits complete separation of aluminum from beryllium. Differential thermal analysis (DT.1) and x-ray diffraction were employed by Goode and Kenner (4OA) to detect intermediates formed in the precipitation of basic iron(II1) formate. Hydrolytic precipitation of the formate comples in chloride c;olutions produced p-FeOOH, which was converted into the 0-FeOOH structure 11ylong heating. Precipitation of inetsl sulfides by direct reaction with thioacetamide (TAA) has received considerable study. Taylor, Smith, and Swift (109A) found that the rate of mercury(I1) sulfide precipitation is inhibited by TAA. Preliminary evidence for stable mercury TALAcomplex formation was obtained. Monochlorocadmium(I1) was observed to undergo more rapid direct reaction with T.l.4 than aquocadmiuin(I1) or higher chlorocadmium Pryszczewska (11) species (56A). (929) obtained a kinetic rate expression for precipitat'ion of lead sulfide via the direct reaction mechanism in ammonia buffer. Similar studies by Klein and Swift (63A) 011 zinc sulfide and Klein el al. (66A) on nickel sulfide in ammonia indicate that two mechanisms are occurring siniultaneously : hydrolysis of
Element Copper Indium Iron Xickel Lead Titanium Uranium
Table 1. Precipitation from Homogeneous Solution Separation" Ref. Technique Conditions Hydrolysis 8-Acetoxvquinaldine, A1 (42A) pH 6, dried, 130" C. Hydrolysis 8-Acetoxyquinaldine, Al, Ca, Mg, Pb ( 5 6 A1 -Al, Ga pH 4.5, 80" C. Hydrolysis S-2-Pyridylthiuronium AI, Ca, Th, Ti (23A) -(Co, Cr, Cu,R l n , bromide, citrate, KHhSCN, pH 4 Xi, Z n ) b pH Increase 1,2-Cyclohexanedione Many metals (57A) dioxime, acetamide, pH 1.2, 90" C. AI, Cu, Fe, AIn, Xi, Zn ( 6 6 A ) Anion oxidation Sulfamic acid, HNOI Cation release H202, pH 2.5 >In,W (25~) Volatilization of 8-Quinolinol. acetone. Mg, Pb, Th solvent fi,L)TA, pH 5.8 Synthesis 2-Yaphthol, NaN02, Al, Ca, Ce, Mg, Pb (88A)
IIOAc,
5 O
c.
Zinc
Hydrolysis
8-Acetoxyquinaldine, .41 acetone, tartrate, pH - M g
Zirconium
Synthesis
2-Naphthol, NaNOz, Al, Ca, Ce, La HOAc, pH 2.3, 5' C. 1-Hydroxy-2-propylAl, Fe, Th, Ti mandelate, 5-6M HC1, 85" C.
(47A1
6.5
Synthesis a
b
(89A) ( Q6A 1
-Indicates interference. Interference removed by masking.
TAA by ammonia and direct reaction of the metals with T A A . The competing effects of ammonia complexes were considered and appropriate rate constants est'imated for the different reacting species. Recently Klein and Swift (64A) have explored in detail suggestions made earlier by Fischer regarding nucleation of metal sulfides. By measurement of absorbance of precipitating solutions as a function of T,1A concentration, regions of first-order and thirdorder nucleation were observed. Firstorder nucleation takes place on inipurities in Ta4A solutions and is removed by filtration. An int,erfacial adsorption mechanism is suggested to account for zero-order TAA dependency in the third-order nucleation process. At high concentrations of TA4 precipitation occurs immediately upon mixing. Jones and Howick (55A) demonstrated that precipitation of nickel(I1) his-dimethylglyoximate from 50% acetone by solvent volatilization yields results comparable to the in situ procedure. Readily filtered crystals were obtained a t p H 8.2 in tartrate media wit,hout interference from iron, cobalt, or copper. Attempts by Dams and Hoste (26.4) to separate niobium and tantaliuni by thermal decomposition of peroxyoxalate complexes in the preFence of tannin in hydrochloric acid were only moderately successful. Coprecipitation studies show that niobium forms true homogeneous mixed crystals with the tantalum precipit'ate. A novel photolytic method for precipitation of tantalum selenite from homogeneous solution was proposed by Yen and
Yang (120il). Tantalum was released from oxalate masking in the presence of selenious acid by oxidation of oxalate with photo-produced bromine atoms. Other procedures employing the P F H S method are summarized in Table
I. Coprecipitation. Only a few of t h e numerous investigations dealing with coprecipitation will be mentioned. A single cocrystallization of radiocobalt from a n alcohol solution of 1nit'roso-2-naphthol in acetate buffer was employed by Dams (Z/tA) to obtain more than 99% carrier-free cobalt. Iiuznetsov et al. (67A) separated curium from 10" times as much magnesium tallization with crystal violet and :lrsenazo I masking agent at' pH 4.5. Coprecipitation of indiuni(II1) with aluminum 8-quinolinate formed by slow evaporation of acetone was ascribed to similarit,y of crystal structures by Lyle and Southern (71A). Scandium, yt,trium, and cerium(II1) are largely rejected by the solid phase. I n another study (9A), Bailey and Lyle found that iron(II1) follows the log distribution law in this system, while zinc is similar to yttrium and rare earths. Klein and E'ontal (61-4) have considered the effects of rate of precipitation, number of growing particles, and rate constants of contamination and purification on the log distribution coefficient. The distribution coefficient a t zero precipitation rate agrees with that predicted for lead-barium sulfate based on solubility product constants. Sorption of zirconium on hydrous iron(II1) oxide in the presence of added phosphate VOL. 38, NO. 5, APRIL 1966
471 R
was investigated by Kolafik and Krtil radiotracers. A mass acium involving an iron(II1)zirconium phosphate complex is suggested by the data. Rudnev and Malofeyeva (97-4) consider the coprecipitation of basic sulfides with acidic sulfides to be a simple matt,er of conipound formation. X-ray diffraction patterns of thallium(1) sulfide coprecipitated with ruthenium(II1) sulfide shon- the existence of T1Ru2Sa. Hahn and Pringle (&A) reduced the cobalt cont'ainination of zinc sulfide by P F H S in t'he presence of excess thiocyanate at pH 2 . The hydrazine-catalyzed TAA reaction was employed to obtain a reasonable rate of precipitation. Xray fluorescence was used by Ronsidler and Sprague (11612) to compare the separation of bariuni chromate from strontium by four methods. A double precipitation with sodium dichromate at p H 4.6 using the I3eyer-Riemann method proved most reliable. Thermogravimetry. Conflict'ing recommendations concerning drying temperatures continue to appear. ,1 thelmograviiiietric (TG-4) study of tungsten(V1) oxide by Carey et al. ( l 7 d ) repoi,ted a weight loss between 650' and 1000' C. which is attributed by Sewkirk and Siinons to reaction with water vapor in a partially closed system (SRA). Volatile tungstic acid is not produced when the analysis is correctly performed. Sinions and Yewkirk (203A) stress the point that, flatness of a plateau is a procedural effect which is dependent on the time needed t,o complete a given transformation before the nest process begins. Calcium osalate is recommended as a model conipound to calibrate TG.1 equipment. I n response to this proposal, Schempf et al. (%A) point out that calcium oxalate is a poor standard unless the history of the sample is known. Significant deviations in the thermogram of different calcium oxalate preparations were introduced by 0.1 to 0.27, sodium impurity. Keattch (59.4) confirins and disagrees with reported drying temperatures for aluminum 8-quinolinolate. The chelate may be dried a t 150' C. and the oxide is formed a t 700" C. A careful investigation of zirconium-hafnium inandelates proved that these compounds contain more than the t'heoretical amount of acid. ,Iceording to hdams and Holness ( I A ) , the escess free acid is very difficult to reniove by washing. 1Ieyer et al. (7'6A) present TGA and DT-1 information on metal chelates of S-benzoyl-S-phenylhydroxylaniine (13PH.i). I n all cases the composition was nearly theoretical and no stahle hydrates were observed. The thermal stability series of BPHd conipounds does not appear to follow any simple atoniic relationship. 472 R
e
ANALYTICAL CHEMISTRY
GRAVIMETRIC DETERMINATION
ing or prior separations. Thorium RPHA mas re-examined by Das and Shome (SSA) in acetate buffer (pH 4.5) plications proposed for gravimetric using a controlled temperature of 50' determination of the elements is preto 55' C. I n contrast to previous resented in Table 11. Ot,her more specific sults, the thorium salt was found to contributions requiring additional comhave theoretical compositon and may be ment are included in following sections. dried a t 110' C. rather than ignited to Alkali Metals-Alkaline Earths. the oxide. The x-ray crystal structure The a-methosyphenylacetic acid of U02 (Ox)?(HOs) has been remethod of Reeve has received further ported by Hall et al. (45.4). It is of study by Holzapfel and Xenning (4BA) using the a-methosy-p-chlorophenyl interest to find that all three 8-quinolinol ligands are 0-metal bonded, derivative. Sodium is precipitated in coplanar, and perpendicular to the methanol-mter a t 0' C. using the linear uranyl ion. Only two molecules potassium diacid salt. A gravimetric of osine are S-metal bonded with the or alkalimetric finish was employed third osine nitrogen in the znitter ion without need of a correction factor. form. More recently Holzapfel et al. (50A) Cobalt - Copper - Nickel - Platinum have described the applicatioii of aMetals. Lingane (69.4) repeated methosy-2-naphthylacetic acid to the earlier experiments with potassium determination of sodium in t,he presence hexanitrocobaltate(II1) and discovered of all of the alkali metals with an error t h a t t'he method for cobalt could be +1.0%. Ross ( 9 6 8 ) has attempted to improved. By performing the precircumvent the many difficulties incipit'ation a t 100' C. rather than 70' herent in the zinc uranyl acetate method C.,complete oxidation of cobalt(I1) for sodium by using a standardized is assured before precipitation begins procedure and Na*2 radiotracer to corand the salt is obtained in anhydrous rect for solubility losses. Sodium tetraform. Uis- biacetylmonosimeethylene(p-chlorophenyl) borate was prepared by diimine and bis-biacetylnionoxime-oC a s w e t t o et al. (18Aj and tested as phenylenediimine form insoluble 1 to 1 precipitant. dlthough potassium was chelates iTith nickel and palladium. precipitated at 0' C., gravimetric reAilthough X a t h u r and Sarang (74-4) covery was unsatisfactory. have prepared a polydentate ligand for Gravimetric separation of calcium these metals, apparently some of the osalate in ammonia buffer containing selectivity of the a-diosime structure 8-quinolinol-5-sulfonic acid masking has been lost. Many interferences can agent was evaluated by Naynes (75A). be eliminated by tartrate or cyanide The solution is acidified to p H 6 before masking. filtration. Coprecipitation errors Gabbe and Hume ( $ 7 ~ 4 ) offer a amounted to 0.1 mg. in the direct desimple high temperature osidation systermination of calcium in silicates. tem for disolving platinum metals. Monk and Exelby (789) have critically The sample is mixed with potassium tested the hexaniminecobalt (111) chlopyrosulfate and potassium chloride ride method of Pirtea for gravimet'ric deand sealed in a Vycor tube. The termination of beryllium. The unauthors suggest that t,he metals may be certainty in water of hydration is the oxidized by chlorine when the tube is main problem. On application of an heated. Fire assay procedures coniniproved procedure and drying at 32% tinue t,o occupy the attention of rerelative humidity, the salt contains 10.8 search laboratories working with platto 11.1 molesof water. inum metals. h 98% over-all recovery Scandium Earths-Titanium Earths. of iridium froni ores was reported by Sharma (1009) has restudied the reacFaye et al. (54A)using a tin button tions of o-nitrophenylarsonic acid with collector and tin ponder reduction of titanium, zirconium, bismuth, tin, thothe parting solution. Procedures for rium, and uranium. -111 form precipiosmium employing the iron-nickeltates in the p H range 4 to 6 and suffer copper alloy collector and for palladium from interference of iron, chromium, using a lead button collector are dephosphate, and organic hydrosy acids. scribed by Van Loon and I3eamish Useful separations of these elements (112-4) and hgrawal and Ueaniish (SA). from copper, lead, manganese, and Controlled potential electrolysis was rare earths are presented. On the successfully applied to copper-pallaother hand, the l,3,5-trbj lJ2,4-tridiuni alloys by Danh and Viguie (97-4). and 1,2,4,5-tetrabenzenecarbosyIic acids Palladium was plated from hot acid are nearly specific for zirconium-hafnium sulfate media and copper from hydrosylin 0.6.11 nitric acid. However, these amine hydrochloride solution a t room 1 to 1 complex d t s described by temperature. Mukherji (79A) must be ignited to Nonmetals. Several applications of the oxide. Only sulfate ion seriously tetraphenylarsonium chloride have interferes. received further study. Glover and Selective precipitation with BPH.1 Rosen (39il) found that excess reagent may be obtained by appropriate maskconcentration must be carefully con-
-1summary of new reagents and ap-
trolled in order to determine perchlorate. h 2- to 2.5-fold acesq is suggested as the best compromise between incomplete precipitation and serious coprecipitation of excess reagent. Small amounts of chlorate and bromate do not interfere. Nitron and tetraphenylarsonium chloride precipitants for fluoborate were compared by Xffsprung and Archer (LA). The latter method \+a$ found to be as good as the best methods currently available. Another definitive study of the phosphoniolybdate method for phosphate 1% as reported b y ,lrcher and coworkers (SA, 7A). Experiments were performed using both Pazand M 0 9 9 radiotracers. Optimum conditions of acid concentration, temperature, and time of standing are given. Heslop and Pearson (46-4) confirmed pievious reports that iron(II1) inhibits precipitation of
phosphate and arsenate in the phosphomolybdate method but incorporation of excess molybdate in the structure compensates for this effect to some extent. A rapid separation of selenium from tellurium and small amounts of many metals is based upon reduction with hydroxylamine sulfate in a citrateacetate buffer containing copper sulfate. Konova ( S S A ) recommends dissolving the copper selenide precipitate and titration with EDTA. TITRIMETRIC ANALYSIS
Titrimetric procedures continue to be dominated by chelometric analysis, as may be best represented by the number of reviews which have been written in this field in the past two years. Five publications dealing with chelometric methods ( 6 B J 11B, ILB, 17B, 79B) as
Table II.
Element Ant imony
Beryllium
Reagent 1,2-DimorpholyIethane
Gravimetric Separation
Conditions lilf HC1, K I (YO2 or HzOz), dry, 140" C.
Diantipyrylpropylmethane
3M HC1, thiourea, ascorbic acid
2-Phenacylp yridine
pH 4, EDTA, dry, 110" C. (NH4)2C03, tartrate, EDTA, EtsO, dry "3, (YH&SOd, XazSOS citrate, at 80" C. pH 4.6, acetate-citrate, K I at lo", dry, 40" C. "8, (EDTA, citrate or KCN), SaOH, boil pH 6.7, KCK, ignite to oxide
Hexamrninecobalt(II1) chloride
well as nine concerning indicator. (25B, S8B, 39B, QSB, Q6B, 69B, SLB, 34B, IOTB) w e indicative of this activity. -1s might be expected with such a large number of workers in a field, considerable duplication of effort results. I t is hoped that these specialized reviews will aid in reducing the number of repetitious publications. Duplication of effort in regard to indicators perhaps could he alleviated somewhat if referees and editorb ~vouldinsist on the inclusion of color index numbers when available. Other reviews of interest in this area include acid-base titrations in alcoholic medium (86B), thiomercurimetric titrations (110B), and iodometry (4RB). d number of papers have been concerned n i t h a mathematical treatment of titration curves and end point errors as well as the effect of
Separation" As(III), Sn(1V) -Ag, Bi, Fe(II1) As(III), Bi, Cu, Fe, Zn -Cd, Gn(I1) Cu, A1 hlany metals -(po4-3, SOn-2)b Ce, Pu, many metals, -Xi Many metals -Bi, Cd, Hg, Pb, Pd, Pt, T1 Anions, many metals
Xercury
Controlled potential electrolysis, - 1.00 V. US. S.C.E. Trimet hylphenylammonium iodide 1-Amidino-2-thiourea
Lanthanum
S-Benzoyl-S-phenylhydroxyl-
3lolybdenum
1-Kitroso-2-naphthol
pH 2.3, EDTA, H~OZ, ignite to oxide
( l l a n y metals)* -C03-2, citrate, F-, Ce Fe, Ti, V -(Co. Cu., U')* ,
Nickel
Bis-salicylaldehyde-ethylenedi-
pH 11.0, K F or KI, dry, 125' C.
A., Co, Fe(III), Hg, Sb, Sn
pH 6.0, tartrate
Ta, many metals -Ti, Zr Many metals -(Au)*, NO$-, Pt, Sod-* Al, Cr, La, >In -Fe, tartrate, U F-, Po4-3, Te, many metals -Ag, Cd, Hg, Pb, T1 30 metals
Cobalt Gold
amine
Palladium
amine iY-Benzoyl-l\'-(o-tolyl-hydroxylamine) Salicyloylhydrazide
Plutonium
Benzenesulfinic acid
Selenium
Thiourea
Silver Thorium
4-Kitro-l-hydroxy-1,2,3-benzotriazole .T-Phenylanthranilic acid
Titanium
o-Hydroxyacetophenone oxime
Uranium
p-Aminobenzoic acid
Tungsten
,Y-Benzoyl-a\--phenylhydroxyl-
r\;iobium
pH 1.2, tartrate dry, 110" C. 0.15-34 HX03, citrate, ignite to oxide pH 6-7, EDTA, cold, vac. dry pH 3, EtOH-H20, tartrate, dry, 120" C. pH 2.5, NHzOH.HC1, dry, 110" C. pH 2.5, heat, dry to constant weight pH 4, pyridine -HsO, EDTA, ignite to oxide 0.5M HCl, tartrate, heat, dry, 115" C. 4.11 €IC& € 1 2 0 2 , tartrate, ignite to pyrophosphate pH 1, NH4C1, ignite to oxide
amine Zirconium a-Hydroxy-a-toluenephosphoric acid a-lllethoxyphenylacetic acid - Indicates interference. * Interference removed by prior separation or masking.
-w
-41, Ce, Fe(II), U Many metals, P04-3 Many metals U, (Fe, N o , Ti, \')b -Cr(III), F-, Many metals -(F-, S b , Ta, Ti)h,Th -Fe, La, Th, Ti
VOL. 38, NO. 5, APRIL 1966
473 R
pH, auxiliary complexing agents, and foreign ions. Meehan and Chiu (59B) have calculated nephelometric and turbidimetric titration curves from exact scattering theory for various titration conditions. Experimental results are given for titrations of dilute solutions of silver and of bromide. The shape of the nephelometric titration curve of 10-4 to lop6 31 bromide solutions is practically ,independent of the scattering angle or the wavelength, although the sensitivity increases with decreasing angle. The turbidity of the silver bromide increases continually during the titration, so that precise timing of additions and measurements is necessary. The addition of polyvinylpyrrolidone stabilizes the silver bromide sols and the scattering behavior becomes practically constant after the addition of the titrant; however, an empirical correction of - 10% is necessary. Poor titration curves can be improved by using the maximum wavelength permissible and the smallest possible scattering angle. Blakeley and Ryan (IOB)have questioned the use of heterometric titrat’ion to detect intermediate compound formation as clainied by Bobtelsky. The method was found to be useful in locating final end points, but no useful information about transitory products could be obtained. Still and Ringbom (95B)have given a comprehensive mathematical t)reatment concerning the end point in photometric titrations. They have shown that an error will theoretically arise in all titrations when the inflection point is taken as the equivalence point, except where the absorbance curve is perfectly symmetrical. The coincidence of the inflection point and the equivalence point is dependent on the sensitivity of the indicator. Rules are given for applying an indicator correction for the amount of metal bound to the indicator a t the end point. Preciously Ringbom (80B) considered the mathematical treatment of problems from side reactions in acid-base and complexometric titrations. Stokes (96B) has derived general equations relating p H and stoichiometric degree of neutralization in the titration of monoprotic and diprotic weak acids or bases with a strong acid or bai;e. From these equations the nuniber and position of inflection points are derived. Methods for determining ionization constants and preparing titrat,ion curves of monoprotic acids are given. Goldman (S4B) has presented a treatment of redox titrations where the number of electrons involved in each half-reaction is different. Conditions are derived to show the relation between concentration and the equivalence point potential. Tanaka and Nakagawa (101B) have given general theoretical expressions concerning chelometric titra-
474 R
ANALYTICAL CHEMISTRY
tions, including critical factors such as p H , auxiliary complesing agents, and the presence of a second metal. The mechanism and stoichiometry of the EDTA titration of iron(II1) in acetate buffer were investigated by Momoki and Sekino (62B) using copper-PAN indicator. Equilibria a t t’he end point are complicated by sluggish reaction of iron(II1) basic acetate complexes with the copper EDT.1PAN system. If the end point is taken a t the first color change of the indicator, results will be low because insufficient copper EDTA is present to allow the replacement reaction with hydrolyzed iron(II1) to occiir quantitatively. Better results are obtained by titration to the point where the indicator color change persists. These conclusions were reached from absorbance measurements a t 240 mp attributed to iron(II1) basic acetate complexes. Acid-Base Titrations. -4rribas and Allue (2B) have described the preparation of several screened indicators suitable for carbonate or phosphate titrations. The mixed indicators yield two sharp color changes near p H 4 and 8.5. Several authors have devised methods for analysis of hidrazine mixtures. Acetylation was employed as a masking procedure by Malone and Biggers (66B) to permit the determination of I ,I-dimethylhydrazine and hydrazine or monomethylhydrazine in a sample. After titration of total basicity, hydrazine or monomethylhydrazine was blocked by reaction with acetic anhydride in acetic acid. Acidimetric titration using Quinaldine Red indicator measures the 1,l-dimethylhydrazine. By application of salicylaldehyde in an acetic acid solution containing an excess of perchloric acid, Serencha et al. (88B) analyzed mixtures of hydrazine and monomethylhydrazine. Hydrazine forms a stable azine, whereas the monomethylhydrazone is completely hydrolyzed under the titration conditions. Excess acid is back-titrated with sodium acetate in this method. h selective method for determination of azide employs the reaction of sodium nitrite with an acidified sample. The excess nitrous acid is immediately titrated with standard base. Clem and Huffnian (19B) claim that complete formation of nitrogen occurs within 5 to 10 seconds. The method is free from interference of chloride, thiocyanate, nitrate, and perchlorate. Redox Titrations. Ottaway and Bishop (67B) have examined the kinetics of the titration of arsenic and antimony with bromate. The reaction is independent of the nature of the reductant. The rate-controlling step is the fourth-order reaction producing the sct,ive oxidizing species. Rate constants and energy of activation were determined. Positive errors with visual
indicators arise at hydrochloric acid concentrations above 2.531 because of inhibition of bromination of cationic forms of rosaniline. Induced air oxidation of antimony during the induction period occurring when the initial bromide concentration is less than 0.00451 causes negative errors a t hydrochloric acid concentrations in the range of 0.22 to 1.0114. Baur and Bricker (‘713) have used hexamminecobalt(II1) tricarbonatocobaltate(II1) as a titrant in acid media. The reagent is dissolved in bicarbonate solutions in order to increase the solubility. The addition of the titrant to a strong acid solution causes the carbonato complex to decompose, releasing the cobalt(II1) ion. End points for the titration of iron(II), vanadium(IV), and cerium(II1) were determined by visual indicators, potentiometric methods, and photometric methods. Although data are restricted to simple solutions, the method may prove useful for the rapid determination of cerium in the presence of the lanthanides. The reagent solution is not so stable on storage as would be desirable. Solutions stored in the dark exhibited a linear loss in titer of 1.22 X 10-5N per day. Solutions exposed to light were less stable. Poppe and Den Roef (YlB) determined cobalt(I1) in ammoniacal solutions containing glycine by titrating with hexacyanoferrate(II1). The addition of glycine eliminated the interferences of iron(III),copper(II),chromium(111), manganese(II), and vanadium(V). At concentrations less t,han J1 it was not possible to determine the end point accurately by potentiometry, apparently because of poor electrode response. Photometric methods a t 520 mp provided improved sensitivity. Arribas et al. ( S B ) investigated the use of stannous chloride solutions as a reductant in alkaline medium. Glycerol solutions are much more stable to light and atmospheric, osidation than hydrochloric acid solutions. The reducing properties are similar. The addition of not more than 257, ethanol improves the viscosity of the solution. The t,itrant was standardized in saturated carbonate solut,ions using dichromate or hexacyanoferrate(II1). Pantani (6SB) examined the Walden reductor in bromide solutions. The redox potentials are almost 0.13 volt below chloride solutions of comparable concentrations. Several difficulties were encountered with insolubility and air osidation of copper(1) bromide, interference of bromide with subsequent redox titration of vnnadium(IV), and only part’ial reduction of tungsten. bIolybdenum(l’1) is quantitatively reduced to (V) in 1 to 4-11 HIZr and urxniuni(V1) is quantitatively reduced to (IT.’) in 0.3 to 4-11 IIBr. The medium is
not likely to replace the conventional chloride solution; however, the data are useful when work is necessary byith solutions containing bromide. Precipitation n i t h arsenate has been used for the determination of yttrium (91B) and gallium (80Bj. The procedures are based on the dissolution of the precipitates and addition of iodide followed b y iodometric finish. Zatko and Kratochvil (115%) employed solid vanadium(II1) sulfat,e as a reducing agent for the determination of perchlorate. Quantitative reduction to chloride was obtained in 7 to 8-11 sulfuric acid using osmium tetroxide as a Higher acidities resulted in low recoveries due to the slow dissolution rate and high temperature of the reflusing aolution. A t high acid concentrations some chlorine evolution is detected. The determination is finished by tit~rationwith standard silver nitrate. Eiratochvil et nl. reported the use of 2,2’-dipyridine and 1,lo-phenanthroline complexes with ruthenium as fluorescent indicators in cerate titrations (61B) and iodometry (50B). I n the iodonietric titrations t,he soluble fluorescent ruthenium coniples is converted into an insoluble precipitate which does not fluoresce. Among the subsbituted derivatives studied, only the methyl derivatives were satisfactory as indicators. The 5-methyl-1, lO-phenant,hroline complex provided the most intense fluorescence; the 4,4’-diniethyldipyridine complex offered the broadest conditions. Direct and indirect titrations niay be performed under conditions where starch indicator does not function. The indicators are particularly suitable for titrations in colored solutions; however, as might be expected, nonaqueous solvent’s present some difficulty due t,o the increased solubility of t’he precipitated species. Ruthenium complexes with 2,2’-dipyridine and 4,4’-dimethyl2,2’-dipyridine were also examined for utility in cerate titrations (61B). The indicator mechanism is based on the oxidation of the Ru(I1) complex, which exhibits a n orange-red fluorescence, to the Ru(II1) complex, which does not fluoresce. The 2,2‘-dipyridine complex is most suitable for cerate titrations in perchloric acid, whereas the 4,4’-dimethy1-2,2’-dipyridine complex is preferab!e for cerate titrations in sulfuric acid and for permanganate titrations. Lang et ~ l (52B) . recommended 2,2’azino-di[3-ethyl- benzthiazoline-6- sulfonic acid] as an indicator for cerate titrations. This indicator, which appears to he particularly useful for arsenic or antimony titrations, changes from green t o red at)about, 1.15 volts. Precipitation Titrations. Sengupta (87B) has used [Co(SH:J6]CI3for the determination of beryllium. .An excess of the hexammine complex is added to a
beryllium solution containing bicarbonate and carbonate to form the insoluble [Co(XHa ) 6 ] 2 [ Be 4 0 (CO a) 6 1 . The precipitate is dissolved, sodium fluoride added, and the excess acid back-titrated wit,h sodium hydroxide to the phenolphthalein end point. Yoshimura et aZ. ( I l 2 B ) applied hexammine cobaltate(II1) to the determination of silver. cadmium, copper, lead, mercury, and bismuth. The method i. based on the precipitation of a thiosulfate complex-e.g. , [Co(PiHa)a] [=lg(S208j2]-and a subsequent titration. The d v e r determination is finished hy titration of the thiosulfate with iodine and other elements by an E D T A titration. Wawrzyczek (109B) titrated pure solutions of the rare earths with a solution of sodiuni tungstate using either bromocresol purple or a mixture of bromocresol green and methyl red as indicators. The end point of tjhe titration is detected by a combination of dye adsorption on the precipitate and color change in solution. The met’hod offers no improvement over an EDTA titration; however, kt-ith suitable masking agents the method inay offer advantages either as a titrimetric technique. a gravimetric procedure, or a separation method. Tungstate has also been used for the titration of calcium (44B) in ethanol solution with a turbidimetric end point. Baumgaertel and Sprecher (6B) investigated seven methods of determining fluoride. They recommend thorium nitrate as the best semimicrotitrant, although zirconyl chloride is particularly suitable in the presence of other ions. Johnson et al. (41B) have recommended a method for the determination of sulfide in water, sewage, and industrial wastes as a supplement or replacement for the standard evolution methods. Potential interferences are removed by separating the sulfide as zinc sulfide in a n inert atmosphere using inverse suction filtration. Bishop (9B) has proposed cadmium sulfate containing 8-quinolinol-5-sulfonic acid as titrant for the determination of sulfide using a fluorescent end point. Szekeres et ~ l (99B) . prefer methyl thymol blue for the titration of sulfide with zinc in t’hepresence of sulfite and thiosulfate. Chelometric Titrations. Pfibil and Veself (74B) have developed an interesting procedure for the det,erniinat’ion of some binary mixtures of selected rare earths. The rare earths are divided into three groups depending on the stability of their E D T A complexes toward phosphate. Group one earths, consisting of La, Ce, Pr, and Yd, are quantitatively displaced from their E D T A complexes. Group two, Sm, Eu, Gd, Tb, Dy, and Y , are partially displaced, while group three, Ho, Er, Tm, Yb, and Lu, are not displaced. A mixture of one element from
group one and one from group three may be analyzed by t,itrating the sum of the bwo with EDTA using xylenol orange. A second titration of the same solution, after the addition of sodium dihydrogen phosphate, using zinc as the titrant determines the amount of EDTA released from the grouli three rare earth ion. Excellent results are obtained for a number of binary mixtures. The same authors (73B) have triethylenetetraniinehexaacetic used acid (TTHA) for the determination of thorium and iron or aluminum. The procedure is based on the fact. that EDTA is replaced in its t’horiuni complex by TTHA, whereas iron and aluminum are not. An initial titration of the sum of the elements is performed using EDTA. After the addition of an excess of T T H A two titrations are completed on separate solutions using zinc and lanthanum as standard solutions. Zinc forms a 2 to 1 complex with T T H A and lanthanum a 1 to 1 complex. The difference between these titrations is a of the amount, of thorium presally. A similar procedure was used in analyzing mixtures of thorium and scandium (76B). Gattow and Gotthardt (33B) determined bismuth by Iirecipitation with cupral (sodium S,S-diethyldithiocarbaniatej and extraction with chloroform. The cupral is destroyed with nitric acid and bismuth titrated with EDTA. A large number of ions do not interferenotably antimony, tin, lead, and arsenic. Pietrzyk and Belisle (70B) have used diethylenetriamine in t’he photometric t’itration of mercury. They have found that the addition of iniinodiacetic acid as an auxilary complesing agent ensures the complete titration of mercury with diethylenetriamine before copper reacts with the reagent. The end point is determined by following the adsorption of the copper-trien complex. Combs and Grove (20B) have studied photometric titrations of mistures of alkaline earths with EDTA. Some mixtures can be resolved-e.g., calcium and barium-by titration to an end point with Eriochrome Black T for the calcium and to an end point wit’h methyl thymol blue for the sum of the calcium and barium. Mixtures of strontium and barium gave no detectable end point and magnesium cannot be tolerat,ed in the procedure. Several publications have considered the determination of cadmium and zinc in the presence of each other, following the work of Fabregas. Flaschka and Butcher (86B, R7B, 29Bj used the stability of the cadmium iodide coinplex to displace the chelating agent or mask the reaction of cadmium. Xylenol orange was used as an indicator with either EDTA or diethylenetetraminepentaacetic acid (DTPA) as a reagent. A large number of interVOL. 38, NO. 5 , APRIL 1966
* 475 R
ferences were studied. I n another publication the same authors (28B) used ethylene glycol-bis(P-aminoethylether) N,A"-tetraacetic acid (EGTA) in a photometric titration of cadmium in the presence of zinc using zincon indicator. Small amounts of calcium are titrated with cadmium; however, if the concentration of calcium relative to cadmium is in the order of a few per cent, the calcium is titrated between cadmium and zinc. PEibil and Veseli (7'7B) approach this same problem by precipitating the bis-1,lO-phenanthroline cadmium complex with iodide. Zinc is determined in the filtrate by addition of excess DCTA and back-
Table 111. Method" P P C C C C C C C C C C C C C AB C C, R P C P P R R C C
Element As Ba
Bi Bi, T1 Ca Ca, AsOd-3 Cs or Rb Cu, Hg, Pb Cu co
FGa
Ge Halides
Fe Xln
R
Hg Hg and others 310,
XI0
v
C C R P P-C C R P - R R P - R P-c R C P-c R P - R C AB R C C P - R C P - R P-c C C
hlo
RIo Ni Nb Kb po4-3 po4-3 HPOz sc sc Sm(I1) Ag Ag
so4-2 S-2
Te Th, Sc Y Zn Zr Zr Zr Zr, Th, Ti a AB = acid-base. C = complexometric. R = redox. * Elements that do not interfere.
476 R
e
ANALYTICAL CHEMISTRY
titration with calcium using methyl thyniol blue as an indicator. I n other work (?8B), these authors used pniercaptopropionic acid to mask cadmium, followed by a direct titration of zinc with TTHA. DCTA is added in excess and cadmium determined by a back-titration with zinc. hIekada et al. (60B) used dimercaptosuccinic acid to determine zinc in the presence of cadmium and copper. Some difficulties arc encountered due to the colored ions formed by iron(III), cobalt, and nickel with the masking agent. A very large number of structure mtxlifications of various aromatic ring systems have been examined for possible
Titrimetric Methods Separation*
Th, R E Pb, Cd, Zn, Ca, Ba, Sr Each other, many metals Mg AI, Fe, Rln, FFe, Al, F Each other Al, Fe, Cu, Xi, Cr, Mg Aluminate liquors A1 wastes Each other Each other Metal ions
Oxides Bi Fe, Cr, Ki, Co, C1-, V, NO2 Organ& Cr Cu, Fe, Co, Ni, Zn, Ca, h k , Ba, Ag, Hg Si, Fe
Oxide Alloys Ta, Zr 28 metal salts Many metals Ni plating solution Many metals Many metals, R. E. Gypsum Pyrites Se Each other Silicates Fe, Th, Ti Each other
application as chelometric indicators. Wada and Xakagawa (108B) have measured the acid dissociation constant and metal indicator formation constant of a series of 2-thiazolylazo derivatives. Excellent EDTA titrations of copper in the p H range 3 to 8 were obtained using 4-(2-thiazolylazo)resorcinol (TAR) as indicator. A survey of new or improved procedures of titrimetric analysis for various elements is included in Table 111. LITERATURE CITED
Gravimetric
(IA) Adams, R. W.,Holness, H., Analys t 89, 603 (1964). (2A) Affsprung, H. E., Archer, 5'. S., ANAL.CHEM.36, 2512 (1964). (3.4) Agrawal, K. C., Beamish, F. E., Talanta 11, 1449 (1964). (4A) Anderegg, G., Ezperientia Suppl. 9, 75 (1964). (SA) Anderegg, G., Helv. Chim. Acta 47, 1801 (1964). (6A) Archer, D. W., Heslop, R. B., Anal. Chim. Acta 30, 582 (1964). (7A) Archer, D. \F7., Heslop, R. B., Kirby, R., Zbid.,30, 450 (1964). (8A) Asmus, E., Ziesche, D., 2. Anal. Chem. 210, 177 (1965). (9A) Bailey, T. H., Lyle, S. J., Talanta 12, 563 (1965). (10A) Banerjea, D., Suryanarayana, S. V., 2 . Anal. Chem. 202, 161 (1964). (1lA) Bhat, T. R., Iyer, R. K., 2. Anorg. Allgem. Chem. 335, 331 (1965). (12A) Burger, K., Egyed, I., Magy. Kem. Folyoirat 71, 143 (1965). (13A) Burger, K., Ruff, F., Ruff, I., Egyed, I., Ibid., 71, 282 (1965). (14A) Busev, A. I., Bogdanova, E. S., Zh. Analit. Khim. 19, 1346 (1964). (15A) Campion, R. J., Purdie, N., Sutin, K.,lnorg. Chem. 3 , 1091 (1964). (16A) Candlin, J. P., Halpern, J., Ibid., 4, 1086 (1965). (17A) Carey, M.A., Raby, B. A., Banks, C. V., ANAL.CHEM.36, 1166 (1964). (18A) Cassaretto, F. P., hlclafferty, J. J., Moore, C. E., Anal. Chim. Acta 32, 376 (1965). (19A) Chang, T-H., Lin, J. T., Chou, T-I, Yang, S-K., J . Chinese Chem. SOC. (Taiwan) 11, 125 (1964). (20.4) Crisan, I., Liteanu, C., Studia Univ. Babes-Bolyai, Ser. Chem. 10, 113 (1965). (21A) Dahlby, J. W., Waterbury, G. R., U. S. At. Energv -" Comm., LA-3345 (1965). (22A) Dalziel, J. A. W., Kealey, D., Bnalust 89. 411 11964). (23A) fialziil, J. A. W:,Thompson, XI., Ibid., 89, 707 (1964). (24A) Dams, R., Anal. Chim. Acta 33, 349 (1965). (25A) Dams, R., Hoste, J., Talanta 11, 1497 (1964). (26A) Ibzd., p. 1599. (27A) Danh, T. V.,Viguie, J. C., Anal. Chim. -4cta 33, 532 (1965). (28A) Das, B., Shome, S. C., Ibid., 32, 52 (1965). (29A) Ibzd., 33, 462 (1965). (30A) Day, R. J., Reilley, C. N., AKAL. CHEM.36, 1073 (1964). (31A) Domagalina, E., Przyborowski, L., 2. Anal. Chem. 207, 411 (1965). (32A) Dyrssen, D., Trans. Roy. lnst. Technol., Stockholm 220, 14 (1964). (33A) Edelin de la Praudiere, P. L., Staveley, L. A . X., J . Inorg. Xucl. Chem. 26, 1713 (1964).
(34A) Faye, G. H., Inman, W. R., hlolouehney, P. E., ANAL. CHEM.36, 366 (1864).(35A) Fischer, R.B., Ibid., 37,27A (1965). (36A) Fresco, J., Freiser, H., Ibid., 36, 372 (1964). (37A) Gabbe, 1).It., Hume, D. N., Anal. Chim. Acta 30, 308 (1964). (38A) Gillard, R. D., Irving, H. >I., Chem. Revs. 65, 603 (1965). (39A) Glover, D. J., Rosen, J. XI., ANAL. CHEM.37, 306 (1965). (40-4) Goode, J. V., Kenner, C. T., Ibzd., 37, 123 (1965). (41A) Gottschalk, G., Dehmel, P., 2. Anal. Chem. 212,380 (1965). (428) Graham, R. P., Billo, E. J., Thompson, J. A,, Talanta 11, 1641 (1964). (43A) Haberman, N., Gordon, L., Ibid., 11, 1591 (1964). (44A) Hahn, R. B., Pringle, D. L., Anal. Chim. Bcta 31, 382 (1964). (45A) Hall, D., Rae, A. D., Waters, T. N., Proc. Chem. SOC.1964,21. (46A) Heslop, R. B., Pearson, E. F., Anal. Chim.Acta 33, 522 (1965). (47AI Hikime, S., Gordon, L., Talanta 11, 851 (1964). (48A) Holcomb, H. P., ANAL. CHEM.37, 415 (1965). (49A) Holzapfel, H., Nenning, P., Z. Chern. 4, 151 (1964). (5OA) Holzapfel, H., Nenning, P., Schlegel. R., Z . Anal. Chem. 213, 401 (19657. ' (5lA) Howick, L. C., Rihs, T., Talanta 11, 667 (1964). (52A) Hseu, T-XI., Wu, S-F., Chuang, T-J., J . Inorg. Nucl. Chem. 27, 1655, (1963). (53A) Hull, J. A., Davies, R. H., Staveley, L. A. K., J . Chem. SOC.1964, 5422. (54A) Irving, R. J., Talanta 12, 1046 (1965). (%A) Jones, J. L., Howick, L. C., Ibid., 11, 757 (1964). (56A) Jones, J. P., Hilemen, 0. E., Gordon, L., Ibid., 11, 860 (1964). (57A) Jones, P. D., Newman, E. J., Analyst 90, 112 (1965). (58A) Kaimal, V. R. hl., Shome, S. C., Anal. Chim. Acta 31, 268 (1964). (59A) Keattch, C. J., Talanta 11, 543 (1g64). (60A) Klein. D. H., Fontal, B., Ibid., 1 1 , ' 1231 (1964). (61A) Ibid., 12, 35 (1965). (62A) Klein, D. H., Peters, D. G., Swift, E. H., Ibid., 12, 357 (1965). (63A) Klein, D. H., Swift, E. H., Ibid., 12.' 349 (1965). (64Aj Zbid' p. 363. (654) K o l k k , Z., Krtil, J., Collection Czech. Chem. Commun. 30, 724, 824 (1965). (66A) Koles, J. E., Shinners, P. A., Ragner, W.F., Talanta 12, 297 (1965). (67A) Kuznetsov, 5'. I., Akimova, T. G., Eliseeva, 0. P., Radzokhim. Melody Onrpd. Mzkroelementov. Akad. N a u k ~!5'8SlZ,Sb. Statez 1965, 44. (68A) Liang, S-C., Wang, S-J., Hua Hsueh Hsueh Pao 31, 174 (1965). (69A) Lingane, J. J., Anal. Chim. Acta 31. 315 (1964). (7OA') Longo, F. R., Ventresca, A., Drach, J. E., McBride, J., Sauers, R. F., Chemist-Anal.ust 54, 101 (1965). (i1A) Lyle, S: J., Southern, D. L., Talanta 11, 1239 (1964). (72A) RIajumdar, A. K., Pal, B. K., J. Indzan Chem. SOC.42, 43 (1965). (73A) llargerum, D. W., Janes, D. L., Rosen, H. XI.,J . Am. Chem. SOC.87, 4463 (1965). (74A) Nathur, N. X., Narang, C. K., Talanta 1 1 , 647 (1964). (75-4) LIaynes, A . D., Anal. Chim. Acta 32, 288 (1965). ~I
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176-4) Mever. R. A,. Hazel. J. F.. McNabh, W. M., Ibld., 31, 419 (1964): (77A) hlilyukova, M. S., Zh. Analit. Khim. 19, 1326 (1964). (78A) Monk, R. G., Exelbv. K. A., Talanta 11'. 1633 (1964). " (79A) Mukherji, A.'K., AKAL.CHEM.36, 1064 (1964). (80A) Murty, A. S. R., Indian J . Chem. 3 , 298 (1965). (81A) Nadkarni, R. A., Haldar, B. C., J . Indian Chem. SOC.41, 319 (1964). (82A) Newkirk. A. E.. Simons. E. L.. ALAL. CHEM.'3?, 146 11965). ' (83A) Nonova, D., Godishnik Sojiiskiya Univ. "K1. Okhudski" Khim. Fak. 57, 113 (1962-3). (84A) Norkus, P., Zh. Analit. Khim. 19, , 518 (1964). (85A) Olsen, E. D., ANAL. CHEM. 36, 2461 (1964).
(119A) Yaguchi, H., Kajiwara, T., Bunseki Kagaku 14, 785 (1965). (120A) Yen, J-Y., Yang, W., Sci. Sinica (Peking) 13, 343 (1964). (121A) Yen, J-Y., Yiing, C-H., Liu, H-Y., Hua Hsueh Hsueh Pao 30, 562 (1964).
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(88A) ibid.,'p. 505. (89A) Patil, 9. 17.,J . Karnatak Univ. 8 , A- (19631. ( 9 0 ~ Pilitington, ) E. s.,Wilson, w., Anal Chim. Acta 33, 577 (1965). (91A) Poddar, S. N., Indian J . A .d. . Chem. 26, 153 (1963). i92A) Pryszczewska, M., Talanta 11, 671 11964). (93A) Ripan, R., Sacelean, V., Ibid., 12, 69 (1965). (94.4) Rorabacher, D. R., XIargerum, D. W., Inorg. Chem. 3, 382 (1964). (95A) Ross. W. J., ANAL.CHEY.37, 168 (1965). (96A) Rowe, J. C., Gordon, L., Jackson, W7.G., Talanta 12, 101 (1965). (97A) Rudnev, X. A., Malofeyeva, G. I., Ibzd., 11, 531 (1964). (98A) Schempf, J. &I., Freeberg, F. E., Angeloni, F. M.,ANAL.CHEM.37, 1704 (1965). (99A) Schilt, A. A , , Sutherland, J. W., Ibzd., 36, 1805 (1964). (100A) Sharma, G. K., J . Proc. Inst. Chemists (Indza) 36, 144 (1964). (101A) Sharma, H. L., Mukerji, S. K., Bull. Chem. SOC.Japan 38, 1086 (1965). (102A) Shome, S. C., Das, H. R.. Anal. Chzm. Acta 32. 400 (19653. (103A) Simons, 'E. L:, Newkirk, A. E., Talanta 1 1 , 549 (1964). (104A) Singh, B. R., Kumar, S.,Indian J . Chem. 3,410 (1965). (105A) Singh, H., Sharma, K. C., Indian J . Appl. Chem. 28, 43 (1965). (106A) Sudmeier, J . L., Reilley, C. N., A N A L . CHEM. 36, 1698, 1707 (1964). (107A) Sun, P-J., Fernando, Q., Freiser, H., Ibid., 36, 2485 (1964). (108A) Takamoto, S., Fernando, Q., Freiser, H., Ibid., 37, 1249 (1965). (109A) Tavlor. D. C.. Smith. D. RI..' ' Swift, E: H.; Ibid., 36, 1924 (1964). (llOA) Uhlemann, E., Fritzsche, P., Z . Anorg. Allgem. Chem. 327, 79 (1964). (111A) Uzumasa, Y., Hayashi, K., Xurishi, Y., Bunseki Kagaku 14, 902 (1965). (112A) Van Loon, J. C., Beamish, F. E., ANAL.CHEM.36, 872 ( 9 6 4 ) . (113A) Yasilkv, T'. lr.,Sitko, I. L., Vestn. Leningr. Univ. 19, Ser. Fiz. i Khim., 165 (1964). (114A) Walton, A. G., Science 148, (3670) 601 (1965). (115A) White, W. W.,Zuber, J. R., AXAL.CHEY.36, 2363 (1964). (116A) Wonsidler, G. J., Sprague, R. S., Anal. Chim. Acta 31, 51 (1964). (117A) Wood, P. B., Higginson, W.C. E., J . Chem. SOC.1965. 2116. (118A) Wright, D. L., Holloway, J. H., Reilley, C. N., ANAL. CHEM.37, 884 (1965). \ _ _ _ _
Titrimetric
(1B) Aliotta, G., Casal, A. R.,Anales Asoc. Quim. Ara. 52. 223 11964). (2B) ArAbas, S.,"All&, A., ' Chih. Anal. (Paris)46, 196 (1964). (3B) Arribas, S., Rincbn, R., Moro, R., Alvarez, hf. L., Anal. Chim. Acta 33, 205 (1965). (4B) Ralabanoff, L., Schmidt, E., Seeger, B., 2. Anal. Chem. 204, 107 (1964). i5B) Barnard. A. J.. Broad. W. C.. Rev. Lfniv. Ind. Santander 6 . 70 11964).'
CHEM.37, 1461 (1965). (8B) Bil'tyukova, E. P., Steklo, Injorm. Buul. Vses. Gos. Sauchn.-Issled. Inst. Slekla 1963, 11. (9B) Bishop, J. A., Chemist-Analyst 54, 115 (1965). (10B) Blakeley, St. J. H., Ryan, D. E., Anal. Chim. Acta 30, 346 (1964). (11B) Boumans. P. W. J. 11..Chem. Weekblad 60. 229. 249. 266 (1964) (12B) Brinkman, v'. A. Th., Chem.'Tech. (Amsterdam) 19, 365 (1964). (13B) Bruno, E., Ciurlo, R.,Rass. Chim. 15, 265 (1963). (14B) Budevski, O., Dzhonova, L., Zavodsk. Lab. 30, 1066 (1964). (15B) Budevski. 0.. Pencheva. L.. Russinova, R., Russeva, E., Talanta 1 1 , 1225 (1964). (16B) Bykovskaya, Yu. I., Zh. dnalzt. Khzm. 20, 178 (1965). (17B) Carreja, J., Fernandez, J. RI., Trivino. F.. Mater. Construc.. Cltzmos Avances 114, 37 (1964). (18B) Chang, W. P., Min, S.K., Chung, I. B., Chemist-Analyst 54, 41 (1965). (19B) Clem, 11. G., Huffman, E. H., . 4 ~ . 4 CHEM. ~. 37, 366 (1965). (20B) Combs, H. F., Grove, E. L., Ibid., 36, 400 (1964). (21B) Cyganski, A., Chem. -4nal. (Warsaw)9, 103, 749 (1964). (22B) Date, Y., Toei, K., Bull. Chem. SOC.Japan 36, 518 (1963). (23B) De Sousa, A,, Injorm. Quim. Anal. (Madrid) 14, 127 (1963). (24B) Dikshitulu, L. S. A., Rao, G. G., Z . Anal. Chem. 202, 344 (1964). (25B) Ditz, J., Chem. Listy 58,946 (1964). (26B) Flaschka, H., Butcher, J., ChemzstAnalyst 54, 36 (1965). (27B) Flaschka, H., Butcher, J., Mikrochem. J . 7 , 407 (1963). (28B) Flaschka. H.. Butcher. J.. Mikrochim. Ichoanal. Acta 1964, 401' (29B) Flaschka, H., Butcher, J., Talanta 11, 1067 (1964). (30B) Flaschka, H., Garrett, J., Ibid., 1 1 , 1651 (1964). (31B) Fujinaga, T., Takagi, O., IC'ippon Kakagu Zasshz 86, 67 (1965). (32B) Gagliardi, E., Ilmaier, B., 2. Anal. Chem. 204,410 (1964). (33B) Gattow, G., Gotthardt, B., Ibid., 206, 331 (1964). (34B) Goldman, J . A , , Anal. Chim. Acta 33, 217 (1965). (35B) Gusev, S. I., Shchurova, L. ?VI., Zh. Analit. Khim. 19, 964 (1964). (36B) Hennart., C.,, Talanta 12, 694 (1965). (37B) Hoffmann, E., Saracz, A., Z . Anal. Chem. 199, 6 (1963). (38B) Hol, P. J., Chem. Tech. (Amsterdam) 19, 223 (1964). (39B) Ibid., 20, 8 (1965). ~
VOL. 38, NO. 5 , APRIL 1966
477 R
(40B) Hung, S-C.,Chang, H-S., Hua Hsueh Hsueh Pao 30, 492 (1964). (41B) Johnson, C. R., McClelland, P. H., Boster, R. L., ANAL.CHEM.36, 300 (1964). l - _ _ - ,
(42B) Justatowa, J., Wiadomosci Chem. 17, 477 (1963). (43B) Kellner, A., Szekeres, L., Magy. Kem. Lapja 20, 327 (1965). (44B) Kharitonovich, K. F., Chepelevetskil. 11.L.. Zh. Analit. Khim. 20. 743 (1965). ’ (45B) Koelling, W., Chem. Tech. (Berlin) 15, 747 (1963). (46B) Koerbl, J., Pharmacotherap. 1963, 107. (47B) Komatsu, S., Kitazawa, C., Hatanaka, T., Sippon Kagaku Zasshi 85, 435 (1964). (48B) Kostin, N. Y., Vargina, R. V., Vestn. Mosk. Univ., Ser. 11, Khim. 20, 45 (1965). (49B) Kozyreva, L. S., Kuteinikov, A. F.. Zharova. X. P., Zh. Analit. Khim. 19; 1515 (1964). ’ (50B) Kratochvil, B., White, hl. C., Anal. Chim. Acta 31, 528 (1964). (SIB) Kratochvil, B., Zatko, D. A., AKAL.CHEV.36, 527 (1964). (52B) Lang, H., Hoenel, H., Hahn, H., Z. Anal. Chem. 201, 321 (1964). (53B) LeGoff, P., Tremillon, B., Bull. SOC.Chim. France 1964, 350. (54B) Luk’anov, V. F., Knyazeva, E. M., Orekhova, K. I., Zh. Analit. Khim. 17, 931 (1962). i55Bj AIcCloskev. J. P., Platina 51, 689 (1964). (56B) hlalone, H. E., Biggers, R. A., A K ~ LCHEY. . 36, 1037 (1964). (57B) Marple, L. W.,Talanta 11, 1268 (1964). (58B) Meditsch, J. O., Anal. Chim. Acta 31, 286 (1964). (59B) Meehan, E. J., Chiu, G., ANAL. CHEW36, 536 (1964). (60B) Alekada, T., Yamaguchi, K., Ueno, K., Talanta 1 1 , 1461 (1964). (61B) hlizuno,. K.,, Bunseki Kaqaku 14, 410 (1965). (62B) Nomoki, K., Sekino, J., Ibid., 13, 213 (1964). (63B) Namiki, II.,Nippon Kagaku Zasshi 85, 126 (1964). “
I
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478 R
ANALYTICAL CHEMISTRY
(64B) Nazarenko, J7. A,, Lebedeva, N. V., Vinarova, L. I., Zh. Analit. Khim. 19, 87 (1964). (65B) Nikitina, E. I., Adrianova, X. N., Zavodsk.Lab. 31, 654 (1965). (66B) Nonova, D., Tuzsuzova, A., Mikrochim. Ichnoanal. Acta 1964, 784. (67B) Ottaway, J. >I., Bishop, E., Anal. Chim. Acta 33, 153 (1965). (68B) Pantani, F., Ibid., 31, 121 (1964). (69B) Partashnikova, hl. Z., Shafran, I. G., Tr. Vses. Nauchn.-Issled. Inst. Khim. Reaktivov 25. 258 (1963). (70B) Pietrzyk, D. J:, Belisle, J., Anal. Chim. Acta 32, 515 (1965). (71B) Poppe, H., Den Boef, G., Talanta 12, 625 (1965). (72B) Pfbil, R., Vesel9, V., ChemistAnalyst 53, 12 (1964). (73B) Ibid., 53, 77 (1964). (74B) Ibid., 54, 100 (1965). (75B) Pfibil, R., Veselj., V., Talanta 11, 1197 (1964). (76B) Ibid., p. 1545. (77B) Ibid.. D. 1613. ( 7 8 ~ Ibid.;-L?, j 475 (1965). (79B) Reilley, c. N., ANAL.CHEhi. 37, 1298 (1965). (80B) Ringbom, A., Pure A p p l . Chem. 7, 473 (1963). (81B) Robbins, L. A., Wheelock, T. D., A N ~ LCHEY. . 36, 429 (1964). (82B) Robin, J., Chim.Anal. (Paris) 45, 506 (1963). (83B) Saj6, I., Z. Anal. Chem. 199, 16 (1963). (84B) Sangal, S. P., Chim. Anal. (Paris) 47, 239 (1965). ‘ f85B) Saneal. S . P..Microchem. J . 9, 38 (lY0D).
6B) Schute, J. B., Pharm. Weekblad 99, 769 (1964). (87B) Sengupta, A. K., J . Indian Chem. SOC.41,767 (1964). 188B) Serencha, N. AI., Hanna, J . C., Kuchar, E. J., ANAL. CHEM.37, 1116 (1965). (89B) Shakhtakhtinskii, G. B., Aslanov, G. A,, Shakarov, G. A,, Dokl. Akad. LYaukAzerb. SSR 19, 27 (1963). (90B) Shakhtakhtinskil, G. B., Aslanov, G. A., Veliev, B. S., Azerb. Khim. Zh. 1964, 97. (91B) ShakhtakhtinskiI, G. B., Yeliev, B. S., Aslanov, G. A., Ibid., 1964, 85.
(92B) Sil’nichenko, V. G., Dmitrieva, F. I., Zh. Analit. Khim. 19, 84 (1964). (93B) Simonavicius, J., Jasinskiene, E., Lietuvos T S R Aukstu ‘u Mokyklu Mokslo Darbai, Chem. ir. (!hem. Technol. 5, 5 (1964). (94B) Solymar, K., Somosi, I., Femip. Kut. Int. Kozlemen. 6 . 371 11962). (95B) Still, E., Ringbom, A.,‘Anal: Chim. Acta 33, 50 (1965). (96B) Stokes, R. H., Australian J . Chem. 16, 769 (1963). (97B) Su, Y-S., ANAL.CHEM.37, 1067 (1965): (98B) Szekeres, L., Kardos, E., Szekeres, G. L.. Chemist-Analust “ 53., 40 (1964). (99B) Ibid., p. 115. (100B) Talipov, S. T., Nigai, K. C., Zh. Analit. Kham. 19, 697 (1964). (101B) Tanaka, M., Nakaaawa, G., Anal. Chim.Acta 32, 123 (1965). (102B) Tandon, K. N., Mehrotra, R. C., Ibid., 30, 407 (1964). (103B) Ugol’nikov, N. A., Xar’yanov, B. AI., Tr. Tomskogo Gos. Univ., Ser. Khim. 154,259 (1962). (104B) Umeda., M.,, Bunseki Kaaaku 9. ‘ 172‘(1960). (105B) Yerdi-Zade. A. A.. Albendov.’ A. A., Azerb. Khim.‘Zh. 1963, 149. (106B) Yeselago, L. I., Zh. Analit. Khim. 19, 264 (1964). (107B) 1-ladimirtsev, I. F., Startseva, Z. P.,Tr. Ural’ski Politekhn. Inst. 130, 35 (1963). (108B) Wada, H., Nakagawa, G., Bunseki Kagaku 14, 28 (1965). (109B) Wawrzyczek, W., Wisniewski, W., Z . Anal. Chem. 203, 339 (1964). (llOB) Wronski, M., Wiadomosci Chem. 17, 1 (1963). i l l l B ) Yamamoto. Y.. Ban, T., Ueda. S.. ’ iVippon Kagaku Zasshi 86, 540 (1965). ‘ (112B) Yoshimura, J., Takashima, Y., Murakami, Y., Kusaba, T., Bull. Chem. SOC.Japan 35, 1433 (1962). (113B) Zatko, D. R., Kratochvil, B., AKAL.CHEM.37, 1560 (1965). (114B) Zhivopistsev, V. P., Kalmykova, I. S., Zh. Analit. Khim. 19,69 (1964). (ll5B) Zhivopistsev, V. P., Kalmykova, I. S., Pyatosin, L. P., Uch. Zap., Permsk. Gos. Univ. 25, 108 (1963). (116B) Zhivopistsev, V. P., Selezneva, E. A., Zavodsk. Lab. 29, 1421 (1963). \
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