V O L U M E 2 7 , NO. 4, A P R I L 1 9 5 5 and one arbitary mixture, with good results over a \vide range of composition. I t is also ruit:tl)le for the analysis of oxygenated conipound-h?tli,ocarbon niisturrs other than lacquer thinnet,>. LITERATURE CITED
-4hlers, S.H. E., and O'Seill, L. -4.. J . Oil &. Colour Chemists' dssoc.. 37, 533-61 (1954).
drrnitage. F.. and Kut. S..O f i c . Dig.Federation Paint h T'auiish P r o d u c t i o ~ iU u b s , No. 333, G i l - 8 9 (1952). Bobalek. E. G.. and Bradford. J . R.. PreDrint Bulletin. Dirision of Paint, Plastics, and Printing Ink Chemistry. A M , CHEX Soc., pp. 222-9, September 1954. Criddle, D. W ,and Le Tourneau. R. L., ANAL.CHEX.,23, 1620 I1 QEl 'i \-___,.
Ellis, IT, H., and Le Tourneau. R. L., Ibzd., 25, 1269-i0 (1953). Grad, P. P., Paint, 011, C h e m . Rec., 115, S o . 2 6 , 20 4, 25, 32 34. 36 (1952). .
I
Grad, P. P., and Dunn, R. J . . .~s\L. CHEX..25, 1211-11 (1953). Harms, D. I., Ibid., 25, 1140--55 (1953). Hirt, R. C.. Stafford, 1:. TT-.. King, F. T.. and Schmitt. R. G . , Ibid., 27, 226 (1955). Hobart, E. K., I b i d . , 26, 1291-93 (1954). Jordan, C. B., Ibid.. 26, 1657-8 (1954). Kagarise and Weinherger. C-. S . G o d . Research Rept.s., 22, I45 (Oct. 15, 1954): PB 111438. Kappelmeier, C. P. d.,PaLrzt, Oil, Chem. Ret.. 111, 8-9. 4% 9. 5 4 - i (1 948).
Kappelmeier, C. P. A , , Goor. W. R. van, Neut. J . H. v a n der. and Kist. G. H., Paint T e c h d . , 15, 477-83 (1950). Hrammes, R., and llaresh. C.. A m . D g e s f u f R e p f r . . 42, Proc. An?.Assoc. Textile Chei(iist8 Colovists. P31i-2i (1953).
61 1 (16) Kut. 8..Paint T h r n i a i i Productiorl. 43, S o . 12, 33-5, 60 (1953). (Ii) Satl. Bur. Standards, Circ. 525 (1953,. (151 Paulson, R., J . Oil &. Colnrcr C'iiemisfa' dssoc., 36, 127-30 (1953'. (19) Rochow, T. G., and Stafford. K. K.. A s i r . . CHEU.,21, 190-202 (1949). (20) Ihid.. 22, 206-10 ( 1 9 5 0 ~ . (211 [ b i d . , 23, 212-16 (19Zl1. ( 2 2 ) I b i d . , 24, 232-i (1952). (233) Schaefer, IT. E., and Bec-ker. It-. IT., Ibid., 25, 1226-31 (1953 , (241 Shag-, J. F.. Skillinp, Susan, and Stafford, R. W., I b i d . . 26, 652 (1954). ('25) Shrew, 0. D.. Ibid.. 24, 1692-9 (1952). (26) Shreve. 0. D.. and Heether, AI. K., Ibid.. 23, 441-5 (1951). (271 Yiegel, L. A , . and Swanson, D. L.. J . Porumer Rci.. 13, 189-91 (1954). (2s) Spagnolo, F., -1x.t~.CHEJI..25, 1386-8 (1953). (29) Stafford. R. W., Francel. R. 6.. atid Phay, J. F., ILid., 21, 1454-7 (1949). ( 3 0 1 Stafford. 11. K., Hirt. R. C . , arid Deichert, K,G.. Preprint Bulletin, Dirision of Paint. Plastics, and Printing Ink Chemistry. AM. CHEM.Soc., pp. 230-5 (September 1954). (131) Stafford, R. W.. and Shay. J. F..-4s.t~. CHEM..25, 8-11 (195:3,. ( 3 2 ) Stafford. R. K., and Shay. J . F.. I u d . E , i y , Cheru,, 46, 1625-7 (1954). (:33) Stafford, It. IT., Shay, ,J. F.. and Francel. R . .J., .Is~r.. CHEM., 26, 656 (1954'1, (34) Swanti. .\I. H., I l ~ i d . .21, 1448-53 (19491. ( 3 5 ) Ihid., 25, 1735-7 (1953). (36) Swann. 31. H.. and Esgoito. G. G . , Ihid.. 26, 1054--5 (19541. (37) Zemany, P. D.. Ihid.. 21, 1709-13 (1952'1,
Ferrous Metallurgy
I
H. F. BEEGHLY Jones
P
& Laoghlin Steel Corp., Pittsburgh 30, P a .
R.iCTIC.iL innovations iri ferrous analytical chemistry during the period October 1, 1952, to October 30, 1954, might be grouped into methods more rapid than previously used and those evolved to meet specific new requirements. X-ray fluorescence has heen utilized to an increased extent. Activation and tracer techniques, though restricted for day-today application by lack of read>- access by many laboratories to suitable sources, have beconie eptablished as useful and practical. Reagents that are specific for a given metal or group of elements continue to be adopted as rapidlJ- as t,hey are discovered, S o t e worthy in this category are cuproine and similar specific compounds for copper, mandelic acid and its derivatives for zirconium, chelating reagents: and ion exchange resins. Spectrographic and x-ray diffraction methods have continued as two of the analyst's most versatile tools. Xem- techniques and improved apparatus have increased their utility. The nonmetal constituents in ferrous metals have not yielded t,o these methods, however; such elements as carbon, phosphorus, and sulfur cont'inue to be determined by older methods. Sufficient progress has been made during the past 2 years to warrant the hope that simpler methods will Come into practical use. Sonmetallic compounds in ferrous metals have been of active interest; principal progress recently has been in utilization of new methods developed by the analyst for research on the role of these constituents in metals. Detailed information on recently published work in x-ray spectroscopy (4,13, 21, 2-& 37-35, 44. fluorescence ( 3 , 8, 7'3, 83), activation and tracer methods (1, 6, 7 , 14, 48,45, 69, SO). and separation nirthods (5, 19. 30, 34, 56, 65, 7.7> 76, 84,
88)have i)eeri pul~lisliecl,:LR \vel1 ( 2 ; 60,62: 6.9).
:ii
useful rien- reference book
ACTI\-.A'IIOS AND T R l C E R AIETHODS Activation and tracer methods, though not estensivelj- used in industrial work a t present, have been put to practical use. Carbon, by deuteron bombardment is converted to nitrogen-13, which may be determined by the Kjeldahl method ( 1 ) . Boron may be detected autoradiographically following neutron activation ( 2 0 ) . I n the analysis of mixtures of columbium, tantalum, and titanium, activation methods have been ef'fective ( 6 , 48). For trace constituents, this method is especially useful (@), and a' facilities for activating specimens become more generallj- available, it will undoubtedly find increased application. Similarly, when facilities are installed in more laboratories for accomniodating the relative1)- loiv level of activity necessary, tracer method< will be more widely applied for nnnl>-tical control and research. ALUIIIYV'\l
T h e quantitative isolation of aluminum from other elementin ferrous metals remains the principal obstacle to its accurate determination. Compleving or sequestering agents which have been investigated include: the sodium salt of ethylenediaminetetrancetic acid ( E D T A ) in the presence of potassium cyanidr (Id), thioglycolic acid ( 3 4 ) . nworbic acid follon ing a niercuri
ANALYTICAL CHEMISTRY
612
cathode sep:tr:ttion (41), and animoniuni thiocyanate (80, 81 ). I n the first three methods, aluminum is isolated from the iron compleA by extraction of the aluminum hydrovyquinolate into chloroform; in the latter, the iron is extracted into an ethertetrahydrofuran mixture. Use of polythene apparatus has eliminated the errors associated ivith leaching of aluminum from the glass vare.
ether ( 7 6 ) \yere found to be specific for extracting these elements from acid solution and a basis for their separation. The value of activation and tracer techniques using columbium-95 ant1 tantalum-182 for evaluating the separation procedures wa. established (7, 69, 60). The columbium thiocyanate (64, 88), columbium-pyrogallol (%), and columbium-hydroquinone (40) complexes were explored and practical methods for their utilization in determining columbium described.
BORON
The principal methods for determining boron in ferrous metals involve either spectrographic methods or reaction of boron XT-ith such compounds as quinalizarin, chromotropic acid, or carmine (18, 42, 53) in a medium of concentrated sulfuric acid or with curcumin in aqueous or organic solution (78). All of the above are for determining relatively low concentrations; they are subject to interference from elements commonly present in iron and steel. Isolation of the boron without excessive contamination i3 both time consuming and difficult. S o improvement over these methods has come into use in recent years. The echelle type of grating, which recently became commercially available, provides a promising means for improving spectrographic methods for determining small quantities of boron (44). An autoradiographic technique using neutron irradiation also has shown promise of providing a specific method for detecting boron in steel (20). It is not in widespread use a t present. CARBON
Methods for the determination of carbon in ferrous metals by combustion in oxygen are well established and simple. Exceptions are procedures for the metals with high thermal stability, or with unusually low carbon contents. New fluxes which show promise for the heat-resistant alloys include a cryolite-lead oxide mixture (20 parts of NalAlF6 to 100 parts of PbsOc by weight) (63) and boron trioxide (2.5 parts of B20sto 1 part of sample by weight) (61 ). The conductometric method for measuring the carbon dioxide evolved during combustion continues to gain acceptance for low-carbon materials ( S ) . For highest precision with very small amounts of carbon, the carbon dioxide is trapped in liquid nitrogen, the oxygen is removed, and the amount of carbon dioxide remaining is measured by means of the pressure change of a sensitive manometer (67). CERIUM
-4method for isolating the cerium group (rare earth) elements and estimating the amounts of each involves removal of iron and major steel components with the mercury cathode and concentration of the rare earths by precipitation with ammonium hydroxide using an iron carrier. The combined hydroxides are dissolved in hydrochloric acid; uranium and sodium chlorides are added as an internal standard and spectroscopic buffer, respectively. The specimens are then excited with a direct current arc and their spectra recorded. The procedure is applicable to 1-gram samples of steel containing as little as 50 mg. of rare earths (82). I n another procedure (83) the cerium is coprecipitated with barium as the fluoride in a hydrochloric-perchloric acid solution. Quantities as small as 0.003% of cerium in stainless steel may be determined. COLUMBIUM
Methods for separating columbium from tantalum and for determining each have continued to receive attention. Diisopropyl ether (19, SO), diisopropyl ketone (84), ethyl methyl ketone (36, 56), and mixed butyl phosphoric acids in di-n-butyl
COPPER
The reactions of copper with diethylammonium diethyldithiocarbamate and the more specific reaction v i t h cuproine and neo-cuproine (16, 22, 28, 33) have provided improved methods for determining small amounts of copper in ferrous metal. The former requires use of ethylenediaminetetraacetic acid as a masking agent; the latter utilizes the citrate or tartrate to complex the iron prior to extraction of the copper-organic compound from aqueous solution. Of the extractants tried, chloroform Eeems most effective. Ethyl alcohol is added to the extract t o promote color formation. GASES AND NONMETALLIC COMPOUNDS
9 micro-vacuum fusion unit for determining gases in metals with an accuracy of f 1 0 p.p.m., on 50- to 200-mg. specimens has been utilized (27). The problem of determining gases in highsulfur materials by the vacuum fusion method has been recognized (29). Apparatus for research on gas analysis methods was devised (32, 77, 89, 90). A method for determining oxygen in metals based on irradiation of the oxygen to produce radioactive fluorine-18 has been studied (66). Nonmetallic compounds were studied by isolation methods (25, 46, 55, 67, 86) and spectrographically (38,39). No fundamentally new methods were described. PHOSPHORUS
By the use of the direct-reading spectrograph (IS), phosphorus contents as low as 0.005% were determined successfully. For high purity iron ( 2 3 ) the molybdenum blue method was utilized after removal of iron with the mercury cathode. After reduction to the ferrous state, a cation exchange resin (91) was used to separate iron from phosphorus. The efficiency of the separation was checked by use of phosphorus-32 as a tracer. SLAGS AND REFRACTORIES
The combustion method, when details of the empirical procedure are established and followed closely, provides a means for rapid determination of sulfur in blast furnace slags (10). Dehydration with perchloric acid following fusion with sodiuni carbonate (the fusion requires heating 10 minutes a t 450" and 15 minutes a t 1000" in a electric muffle furnace) provides a rapid method for determining silica in blast furnace slags (12). By use of semimicromethods (17) or spectrographic procedures (71, 7 3 ) a complete analysis of silicates and slags may be effected quickly; only 100 to 500 mg. of sample are necessary. Calcium and magnesium in limestone were determined by titration with ethylenediaminetetraacetic acid (43). The use of p H measurement for evaluation of the basicity of slags has received renen.ed attention (74). SULFUR
Emphasis on development of a rapid stoichiometric method for the determination of sulfur has continued. Evaluations of
V O L U M E 2 7 , NO. 4, A P R I L 1 9 5 5 combustion procedures continue to indicate that, though reproducible, they must be standardized against materials of similar composition and with a range of sulfur contents comparable to those of the un1mon.n samples (11, 61, 70, 72, 79). Recovery of the sulfur content is reported to range from 86 to 100% of the sulfur present. Temperatures required for combustion range from 1300” to 1435” C. and oxygen flows from 1 to 3 liters per minute. Work has been done to simplify and improve the gravimetric ( 9 ) and the evolution methods (SI). Phosphoric has been used in place of hydrochloric acid to liberate the sulfur as hydrogen snlfide from chrome, chrome-nickel, and the nickel steels. I n the gravimetric method, iron has been removed prior to precipitation of barium sulfate by passing a perchloric acid solution of the steel through an alumina column specially treated with ammonia (6‘4). Iron is retained in the column and the sulfur is precipitated in the eluate as barium sulfate. TITAIVIU-M
Following removal of iron with the mercury cathode, titanium was determined polarographically using a supporting electrolyte 1.0, 0.5, and 1.2M in tartaric acid, sulfuric acid, and ammonium sulfate, respectively (26). By use of ethylenediaminetetraacetic acid, titanium was separated from interfering elements and determined by measuring the absorption of the peroxide complex (68). Chromotropic acid was utilized also (47). ZIRCONIUM
Mandelic acid and its derivatives continue to be studied as precipitants for zirconium (49, 58). Generally, the precipitate is ignited to zirconium oxide and weighed. It may be dissolved in aqueous ammonia and the zirconium determined volumetrically (87). Benzilic (45) and tetrachlorophthalic acid ( 6 8 ) also may be used as precipitants in the presence of iron and elements commonly present in steel. SUMMARY
The literature cited in this review includes only a limited number of the articles published in the period from November 1, 1952, to October 30, 1954. I t is intended to include methods with specific application, which appear to be finding increased practical use. Mention has not been made of methods for analysis of the newer metals and alloys, many of which are now produced commercially and used in a manner somewhat analogous to ferrous metals. I t will be appreciated if important omissions are brought to the attention of the editors, so that they may be included in a future article. LITERATURE CITED
(1) Albert, P., Chaudron, G., and Sue, P., Bull.
S O C . chim. France, 1953, C97-102. (2) Am. SOC. Testing Materials, Philadelphia, Committee E-2 on Emission Spectroscopy, “Methods for Emission Spectrochemical Analysis,” 1953. (3) Am. SOC. Testing hIaterials, “Symposium on Fluorescent XRay Spectroscopic Analysis,” Tech. Paper 157 (1954). (4) Beattie, H. J., and Brissey, R. M.,Ax.iL. CHEV.,26, 980-3 (1954). (5) Belcher, R., Sykes, d.,and Tatlow, J. C., A n a l . Chim.Acta, 10, 34-47 (1954). (6) Beydon, J., and Fisher, C., Ibid., 8, 538-45 (1953). (7) Boyd, T. F., and Galan, Michael, As.iL. CHEM.,25, 1568-71 (1953). (8) Brjssey, R. If.,Ibid., 25, 190-2 (1953). (9) Brit. Iron and Steel Research Assoc., Methods of Analysis Committee, J . I r o n Steel Inst., 174, Part 1, 28-30 (1953). (10) Ibid.. 177. 233-8 (1954). (11) Ibid., pp.239-42. (12) Ibid., pp. 243-5. (13) Carlsson, C. G, and Danielson, Lars, Jernkontorets Ann., 138, 383-403 (1954). (14) Claassen, A., Bastings, L., and Visser, J., A n a l . Chim. Acta, 10, 373-85 (1954).
. ,
613
(15) Clark, G. L., AS.iL. CHEM.. 25, 655-748 (1953). (16) Cluley, H. J . , Analyst, 79, 561-7 (1954). (17) Corey. R. B., and Jackson, AI. L., A N ~ LCHEM., . 25, 625-3
(1953).
(18) Cypres, R., and Leherte, P., Bull. soc. chim.Belg .. 63, 101-1-1
(1954). (19) Ellenberg, J. Y.. Leddicotte, G. W.,and 3Ioore. F. L., A x i L . CHEJI..26. 1045-7 (1954). (20) Faraggi, Henriette. Kohn, ’Andrti, and Duomerc. Jean, Compt. rend.. 235, 714-16 (1952). (21) Fry, D. L.. and Schreiber. T. P., J . Opt. SOC.A m ~ r . 44, , 159-62 (1964). (22) Gahler, A. R., = ~ X A L .CHEM.,26, 577-9 (1954). (23) Gates, 0. R., Ihid., 26, 730-2 (1954). (24) Gordon, E. E., Jr.. Jacobs, R. AI., and Rickel, 11. C., Ibid., 25, 1031-4 (1953). (25) Goto, Hidehiro, and Watanabe, Toshio, .~ippon-Iii?l.~i,,cGakkai-Shi, 16, 274-7 (1952). (26) Graham, R. P., Hitchen, A, and Maxwell, J. .1.,Can. J . Chena., 30, 661-7 (1952). (27) Gregory, J. S . , Mapper, D., and Woodward, J. -I., Analyst, 78, 414-27 (1953). (28) Guest, R. J., -4x.i~.CHEX.,25, 1454-6 (1953). (29) Hammer, H. L., and Fowler, R. M., J . Metals, 4, 1313-15 (1952). (30) Hicks, H. G., and Gilbert, R. A., AKAL.CHEX, 26, 1205-6 (1954). (31) Horak, O., 2. anal. Chem., 140, 255-61 (1953). (32) Horton. W.S., and Brady, Joseph, -4s.~~. CHCX.,25, 1,991-8 (1952). (33) Hoste, J., Eeckhout, J., and Gillis, J., -4nal. C h i m . Acta, 9, 263-74 (1953). and Sandell, E. B., Ibid., 7, 308-12 (1952). (34) Hummel, R. 4., (35) Hunt, E. C., and R‘ells, R. d.,Analyst, 79, 345-50 (1954). (3fi) Ibid., pp. 351-63. (37) Hurwita, J. K., ASAL.CHEX.,25, 1028-31 (1953). (38) Hurwita, J. K., AppZ. Spectroscopy, 8, S o . 1 , 28-34 (1954). (39) Hurwitz, J. K., J . Opt. SOC.Amer., 44, 30-4 (1954). (40) Ikenberry, L., Martin, J. L., and Boyer, W.J., AP;.iL. CHPM., 25, 1340-4 (1953). (41) Jean, XI., A n a l . C h i m . Acta, 10, 52G53 (1954). , and Toogood, 31. J., Analyst, 79, 493-6 (1954). , and Robinson, K. L., Chemistry & Industry, 1953, 687-8. (44) Kirchgessner, W.G., and Finkelstein, K.A 1034-8 (1953). (45) Klingenberg, J. J., Vlannes, P. N., and Mendel, 1 2 . G.. Ibid., 26, 754-6 (1954). (46) Koch, Walter, and Bruch, Joachim, Arch. Eisenhiittenw., 24, 457-64 (1954). Iter, and Ploum, Heinrich, Ibid., 24, 393-6 (1953). Chimie & Industrie, 71, 69-77 (1954). (49) Leddicotte, G. W., and Remolds. S.-4.. A S T M Bull.. 188, 2931 (1953). (50) Lingane, J. J., “Electroanalytical Chemistry,” Interscience, New York, 1953. (51) Lochmann, W.,and LIeng,, H., Metallurgic u. Gicssereitch., 3, 336-7 (1953). (52) Lundell, G. E. F., Bright, H. A, and Hoffman, J. I., “Applied Inorganic Analysis with Special Reference t o the Analysis of Metals, Afinerals and Rocks,” 2nd ed., Wiley, New Tork, 1953. (53) Martin, Bull. SOC. chim. b i d , 36, 719-29 (1954). (54) llareys, A. E., Analyst, 79, 327-38 (1954). (55) Massinon, Jean, Rec. mCt., 50, No. 4, 264-74 (1953). (56) Jfercer, R. A., and TT’ells, R. A., Analyst, 79, 339-45 (1954). (57) LIeunier, F., and Flament, F., Rea. mht., 50, 603-16 (1953). (58) Mills, E. C., and Hermon, S.E., Analyst, 78, 256 (1953). (59) AIilner, G. W.C., and Smales, A. A., Ibid., 79, 315-26 (1954). (GO) Ibid., 425-30. (GI) Norimoto, Takeo, Tetsu-to-Hagane, 38, 480-6 (1952). (62) hlurty, P. S., and Rao, Bh. S. V. R., 2. anal. Chem., 141, 93-6 (1954). (63) Korton, P. L., ASAL. CHEST., 25, 1761-2 (1953). (64) Sydahl, Folke, AXAL.C m x , 26, 550-5 (1954). (65) Osborn, G. H., Analyst, 78, 220-1, 221-52 (1953). (66) Osmond, R. G., and Smales, A. A,, A n d . Chirn. Acta, 10, 117-28 (1954). (67) Pepkowita, L. P., and Moak, W. D., ANAL.CHEar., 26, 1022-5 (1954). (68) Pickering, W. F., Anal. Chirn. Acta, 9, 324-9 (1953). (69) Pigott, E. C., “Ferrous Analysis Modern Practice and Theory,” Chapman & Hall, London, 1953. (70) Pontet, I f . , and Boulin, R., C h i m . anal., 36, 98-101 (1954). (71) Price, W. J., Spectrochim. Acta, 6, 26-38 (1953). (72) Rice-Jones, W. G., ANAL. CHEM.,25, 1383-5 (1953).
ANALYTICAL CHEMISTRY
614 (73) Iionir, E. V., aiid \-anhokertal, -1.AI., Rei. m&., 50, 153-S (1953).
(74) St. Pierre, P. D. S.,J . M e l a l s , 5 , 41-3 (1953). ( 7 5 ) Samuelson. O., Lunden, L., and Schranini, K., 2. anal. Chem., 140, 330-6 (1953). (76) Scadden, E. AI., and Ballou, S . E., ANIL. CHEY.,25, 1602-4 (1953). ( 7 7 ) Shields, B. >I., Chipman, John, and Grant, S . ,J., J . M-an. T.L., and lIilliken, Ii. s., .ix.xr~.CHEM.. 25, :36:3--1 ( (90) Yeaton, H . T'aci~zori, 11, S o . 2 , I15--%4(195:3). (91) Toshino, T., H u l l . ('hem. S O C . Japa/r. 26, 401--:3 (1%:;).
Nonferrous Metallurgy M. L. MOSS Aluminum
P
Co. o f America, N e w Kensington, P a .
CBLICATIOS of reseal ch on nonfei rous metallurgical analleis hap continued a t a uniform level of activit? for the past 6 )ears including the interim since the previous revien (181) and up to .4ugust 1964. Emphasis on newer aiid more effective methods of analysis is on the increase, and there is reason to expect this apparent trend to be even more noticeable as consolidation of recent developments proceeds during the next fem Sears. There has been a steady rise in the proportion of work done in foreign laboratories, now corresponding to about 60% of the total publications. Extensive reviem s on the analytical chemistry of titanium ( S I ) , beryllium (187), and uranium (153) ieflect a pronounced increase in the volume of work on the cheniical analysis of these materials. Recent advances in x-ray fiuorescence analysis are rapidly bringing this method into prominence. Because of the relative independence of x-ray excitation on metallurgical structure and the ease of analyzing comparatively large surface areas, the method is not subject to the rigid requirements for sample prepai ation characteristic of spectroscopic methods. X-ray fluorescence analysis is, in general, less sensitive than emission qpectioscopy. I n an air medium, the most favorable situation is the determination of high concentrations of elements of atoniic number greater than 22. Recent developments in production of c i ~ s t a l sand in the use of a helium path promise to extend the method to lighter elements and to lower limits of detection. One of the most interesting developments in spectrographic analysis of metals is the excitation of molten samples. ;Inalysis of certain metals has been complicated heretofore by variables nssociated with structure, including grain size, distribution of constituents, porosity, microscopic shrinkage cracks, and other effects produced during solidification, heat treating, and IT orking. 1 new technique involving excitation of molten metal \\a- proposed by Frederickson and Churchill which erases these socalled metallurgical effects and eliminates undesirable differences in epectral excitation characteristics resulting from variations in previous treatment of the metal (if). .4lthough developed primarily for analysis of aluminum alloys, this general technique should be valuable in the analysis of other metals in u-hich metallurgical history of the sample influences excitation. -4double-focusing mass spectrograph for determining impui itiee in Golids was de-rribed by Hannay (70). Samples in the form of
\\-ires or rods arc excited by ii spark discharge, giving a \Tide spread in initial energies requiring both magnetic and electrostatic focusing. Using photographic plat,es, this instrument can determine 0.1 p.p.ni. of antimony and other element? i n germanium with exposures of 3 to 10 minutes. For higher concentrations, electrical ion det'ection is used. Polarographic and colorimetric methods have been widely used for determining impurities in all metals and in the semiconducting nonmetals. Measurement of gas in metals by vacuum fusion methods has also received considerable attention. Several new and promising applications of neutron activation were reported. Bricker, Furman, and JlcDuffie developed a general technique for the separation of trace amounts of various metals ming a small mercury cathode (18). -4fter electrolj-sir, the mercury amalgam is subjected to distillation, after which t,he metallic residue is analyzed colorimetrically to determine nonvolatile constituents. Among the elements M-hich can be aatisfactorily removed from mercury cathodes are cadmium, cobalt, copper, iron, nickel, and zinc. The method has been applied to uranium, calcium, magnesium, and other light alloys. A LURIISUIZ
dn x-ray diffraction method suitalde for large scale bauxite exploration studies was described by Black (13). Diffracted intensities are converted to mineral percentages using calibration curves based on samples analyzed chemically. Gibbsite, boehniite, kaolinite, quartz, and total iron minerals are determined. Total water, silica, iron oxide, and alumina are then computed from corrected mineral values. Computation, handling, :md listing of data are facilitated by a printing-type recorder, cxlrulating board, and automatic computer. Among the advantagre of the x-ray method in exploration work are a fivefold reduction in time compared to chemical methods, reduced over-all cost by elimination of many chemical determinations otherwise necessary, identification of the minerals present leading t o advance information concerning performance of bauxite in the B,ayer process, and use of very small samples. Characterization of hydrated aluniinas by infrared spectroecopy and application to the study of bauxite ores were reported til- Frederickson (60). Alpha monohydrate (boehmite), alpha
