Table
II.
Material Cr-I’-steel Fcrrochromium
KO.
Certified Vanadium Found, Value, % % Av., yo
XBS 64a
S I:~gnetite-ilmenite 0
values and confirm the validity of the method.
Analysis of Samples for Vanadium
Std. Uev.
0 154
0 162, 0 154, 0 142, 0 154
0 153
0 005
1 100
1 09, 1 07, 1 18, 0 99
1 08
0 045
‘The author wishes to thank the hIaiiagement of -4frican Metals Corp. Ltd. for permission to publish this work. LITERATURE CITED
Ol>taintd by photometric method.
giam per 50 nil. (about 2 x 10-*.U). Interferences. Table I shows a list of metals t h a t are also extracted from a 0 . 5 5 hydro(-hloric or sulfuric acid solution by &hyl acetate plus cupferron. The interference of each of these nicbtals was tested by taking kiioan quantities of vanadiuni aiid each interfering mctal through the whole procedure and ascertaining the amount of each metal t h a t caused a ielativt, trior of 2% in th(x determination of vanadium. The permissible amount shoivn in the table is tho amount piesent in the aqueous bolution prior to mtraction. The amount of intwfcring metal extiacted with the vanadium was not determined. Cerium, tantalum, tin, thorium, tungh t m , and uranium can be tolcratcd in fairly large amounts. Hand and rontinuum spectral inteiference i6 euprv icwcd whmi copper, iron, niobium. tita-
ACKNOWLEDGMENT
nium, and zirconium are present in amounts exceeding the limits indicated in Table I. Copper, iron, tin, a i d molyljdcnum are conveniently removed by electi,olysis with a mercury vathode cell. Fusion of the sample with sodium peroxide and subsequent leaching of tlie melt with water serves to separat,e copper, iron, niobium, tit~aiiium,and zirconium from vanadium. Iron(II1) and molybdenuni(V1) may IJC sc,parated from vanadium(1V) 12)- extraction from aqueous solution 6.0.11 in hydrochloric acid wit’h diethyl ct’hcr. The vanadium remains in the aqueous phasc ( 1 ) . RESULTS
Samples of three diffrreiit materials were analyzed using the method described. The results shown in Tablr I1 agree satisfactorily with the critified
(1) Bock, It., Kusche, H., Bock, K., Z. anal. Chem. 138, 167 (1953). (2) Burriel-Llarti, F., Ramirez-AIufioz, J., iisunciori-0marrenienteria, 31. C.. Inst hzerro y acero 9 , I l i (1956). (3) Foster, 11. l)., Grimnldi, F. S., Stevens. R. E.. I-. S. Geol, Survrv, Rept. 2 11944). ’ (4) Furman, S . H., Mason, R. B., Pekoltt, J. 6 . , h A L . CHEhI. 21, 1325 (1949). ( 5 ) Gaydon, A . G., “Dissociation Energies arid Spectra of 1)iatomic Molecules,” Chapman & Hall, London, 1947. (6) Gilbert, P. T., “Flame Photonwtry-
Sew Precision in Elemental Analysis,!’ Beckman Reprint, R-56, reprinted from Industrial I,aboratories, Beckman Instruments Inc., Fullerton, Calif., August 1952. (7) Herzbrrg, G., “l\Iolecular Spectra and llolecular St,ructure. I. Spectra of Iliatomic Molecules,” 2nd ed., Van Sostrand, S e a York, 19.51. (8) Mahanati, P. C., PTDC.Phy.s. SOC. (London) 47, 433 (1935). (9) Sandell, E. B., “Colorimetric Determination of Traces of Metals,” 2nd ed., Intersciencr, London, 1950
RECEIVEDfor review ,\larch 8, 1960. .4ccepted June 20, 1960. Extracted from part of a thesis t o he pul)mitted by C. ,Ll. Stander in partial fulfillment of requirements for the degree of dortor of vience at thr University of Pretoria.
Gas-Solid Chromatographic Separation of Some Light Hydrocarbons THOMAS A. McKENNA, Jr., and JOHN A. IDLEMAN Firestone Synthetic Rubber and latex
Co., Orange, l e x .
>
A combination column of silica gel and alumina may b e used to resolve some permanent gases and light hydrocarbons through the C4’s. Analyses of hydrocarbons heavier than Ch are feasible at elevated column temperatures, depending upon the sample composition. These same solids may be liquid-modified to shorten analysis time at room temperature without loss of resolution.
T
allalysis Of light hydrocarbon streams from butane drhydrogrnation requires columns capalde of sepai,ating gases from hytlrogc~n through thc common Cq olefins and 1 ,3-hitadicw~. The authors H E CHROMATOGRAl’HIC
have previously reported ( 2 , 3 ) a twocolumn arrangrment for this analysis which involves a gas-solid and a gasliquid column. A single column operating at r,levatcd temperatures 11-ould simplify the procedure. and make it adaptable to a pi’occss chi~oinatograph. Patton, Lewis, and Kaye (4) reported the use of several active solids to separate gas mixtures containing hytlroc.arl)ons through prntanes. Greene and Pust ( 1 ) compared the separating properties of silica gel (Davison c h i c rant grade) and alumiiia (Alcoa F-I) using a mixture of low boiling gasrs and hydrocarhons through 1.3-hutadiwe. ‘I’hc use of silica gel (Davison G l d c 12j at reduced trmperatures is r ~ -
ported by Szulczcivski and Higuchi (6) for the separation of some oxides of nitrogen and low boiling gases. This paper is concerncd primarily n ith the development of a column composed of a combination of alumina and silica gel. This columii is capable of separating the components of a butane dehydrogenation stream, excluding air and caibon dioxide. APPARATUS
-1 Perkin-l
