‘
a t this temperature also separates other low boiling gases such as carbon monoxide and nitric oxide (Figure 3). The order of emergence cannot be directly correlated with the boiling points of the gases. The effective emergence times for a typical run of several gases are compared in Table I. The lower boiling components, such as carbon monoxide, appear t o be adsorbed strongly. As a direct application of these findings the gases present in ampoules of old amy1 nitrite, (Amyl Kitrite Ampuls, Burroughs Wellcome & Co., lot JT143. dateof manufacture, November 26,1951) were identified. The column was cooled in a bath of dry ice-acetone, then the bath was removed, and the column alloned to warm up to room temperature. The gases found were nitrogen, nitric oxide. carbon monoxide, nitrous oxide, and carbon dioxide (Figure 4). This is in agreement with a mass spectrophotometric analysis on a similar sample of gas (11) and indicates the same gaseous decomposition products, with the exception of carbon monoxide, as reported b y Oliveto and Kornblum ( 6 ) ) who characterized
LITERATURE CITED
Table I. Elution Time for Various Gases on 6-Foot Silica Gel Column”
Gas 0 2
h-2 SO
CO
COi S20
Boiling Point -183 -195 -151 -190 -78 -89
0 8 8 0 5 5
Elution Time, Minutes 3 3 4 8b 11 O b 13 2h 22 tic 19 o c
Volume of column S 36 ml At temperature of dry ice-acetone, flow rate: 45 ml. per minute At room temperature, floir rate: 30 ml. per minute. a
( 1 ) Drew, C. M. and McNesby, J.
F;
“Vapor Phase Chromatography, p. 217, Academic Press, New York,
1957. (2) Greene, S. A., 4513 South 31st St., Arlington 6, Va., personal communication, March 18, 1957. (3) Keuleman, -4.I. M., Kwantis, A., Zaal, P., Anal. Chim. Acta 13, 357 (1955). Kyryacos, G., Boord, C. E., ASAL. CHEM.29, 787 (1957). Oliveto, E. P., Kornblum, N., J.Am. Chem. SOC.71, 226 (1949). Patton, H. W., Lewis, J. S., Kaye, I., ANAL. CHEV. 27, 170 (1955). Percival, a. C., Zbid., 29, 20-4
w.
/ ~ n c 7 \
(lJtJ1 J .
the decomposition products of optically active 2-octyl nitrite. Column temperatures lower than room temperature have been used by Keuleman, Kwantis, and Zaal (3) and Drew and McNesby ( I ) . The present work illustrates additional possibilities in this area; the separation of permanent gases is effected conveniently without the use of heat under conditions less likely to produce changes in sample composition.
(8) Perkin Elmer Co., brochure describing Model 1548 vapor fractometer. (9) Ray, N. H., J . Appl. Chem. 4 , 82-5 (19.54). \ - - - - I
(10) Victory Engineering Corp., “Characteristics of VECO Model M 182,” June 1956. (11) Yunker, M., Higuchi, T., unpublished
data. RECEIVED for review March 2, 1957. Accepted May 13, 1967. Study supported in part under a grant from Parke, Davis and Co., Detroit, Mich., and under a research contract with the Armed Services Medical Procurement Agency, New York, N. Y.
Conductances of Solutions Absorbed by Filter Paper ROBERT CRAWFORD and
JOHN T.
EDWARD‘
Chemical laboratory, Trinity College, Dublin, Ireland
b The conductance, K, of a column of solution i s reduced to K’ when the solution is uniformly absorbed by a strip of filter paper of the same length. The ratio K ’ / K has been defined as the “obstructive factor” of the paper strip. The obstructive factors of strips of cellulose filter papers may be related b y an equation, previously developed for pads of nonswelling fibers, to their absorbances-Le., to the volumes of solution held by unit weight of paperif a 10 to 20% increase by swelling in the nonconducting volume of the cellulose i s assumed. The obstructive factors found for strips of fiber glass papers are higher than for strips of cellulose paper, because of their higher absorbances,
A
of solution of specific conductance k . length I, and crosssectional area A will have the conductance, K : COLUMN
Present address, McGill University, IIontreal, Canada.
VI being the volume of the solution. \‘Ye consider the case in Ivhich a volume, V,, of particles of nonconducting solid is uniformly dispersed through the solution, under such conditions that the length of the column remains unaltered but the total cross-sectional area is increased to A’ and the total Although the volume to VI effective cross-sectional area of the solution in the column remains A, its conductance decreases to I
