placed on columns. They were then removed with different acids and recovered from solution. The results of these experiments are shown in Table Y. I n each case, the recovered anion n a s found to be that of the eluting acid, not that of the original QAC salt. Table VI demonstrates the use of the ChIS-cellulose column for concentrating water-soluble QAC from very dilute solutions. Known weights of triniethyloctadecylammonium chloride were added to 500 ml. of distilled water to bring the concentration to 0.1 to 1.0 p.p.m. The entire 500 ml. n-ere passed over the column and the concentrated QAC was determined as described. The recoveries on the average were slightly low. The weight loss, however, appeared to be fairly constant, suggesting
that it was due to the surface activity of the quaternary salt. The ease with which the QAC anions are exchanged on cellulosic columns suggests that the method could be used to Obtain Or prepared &hC. The eluting acids are all relatively strong acids. They must also be soluble in ethyl alcohol or some similar solvent, because aqueous acids produce practically no recover)' from the columns. The choice of anions is therefore limited, but the technique is nevertheless useful.
( 2 ) Elvidge, L). A., Proctor, K. A.7 Baines, C. B., Analyst 82, 367-72 (1957). (3) F ~ F, hf,, ~ J , pham, ~ and ~ Pharmacol. 8, 42-5 (1956). (4) Furlong, T. E., Elliker, p. R.,J. Dairy Sci. 36, 225 (1953). ( 5 ) Harris, T. H., J . A4ssoc, Ofic. Agr. Chemists 29, 310-11 (1946). (6) Miller, D. D., Elliker, P. R., J . Dairy Sei. 34, 279-86 (1951). ,;:# 7 ~ ~ ~ ~J . ~ (8) \\-&on, J. B., J . Assoc. Ofic. Agr. Chemists 29, 311-27 11946). (9) Ibid., 31, 480-4 (1948). (10) Ibid., 33, 666-70 (1950). (11) Ibid., pp. 670-4. (12) Ibid., 37, 374-9 (1954).
(TiFg:OI'j ,&J
LITERATURE CITED
(1) Calman, C., Kressman, T. R. E.,
"Ion Exchangers in Organic and Biochemistry," p. 555, Interscience, Sew Pork, 1957.
RECEIVED for review July 8, 1959. Accepted October 19, 1959. Division of iinalytical Chemistry, 135th Meeting, ACS, Boston, Mass., April 1959.
Standard Titanium-Hydrogen Samples M. J. TRZECIAK' Battelle Memorial Institute, 505 King Ave., Columbus 7, Ohio
b A method is described for making individual titanium-hydrogen standards to b e used in comparing results of analysis by a given laboratory with the amount of hydrogen added to the standard samples. A total of 67 standard samples were analyzed separately by five laboratories. There was agreement between the result of a given laboratory and the amount of hydrogen added to within 3% on 41 samples and to within 6% on 19 samples. Agreement on seven samples was outside these limits.
I
Diffusion pump
dm; r
s view of the growing recognition of
the importance of gas concentrations in metals, there is a need for standard samples to standardize and evaluate techniques for the analysis of gases in metals. A program is described &-hose objective was the preparation of standard titanium-hydrogen samples (6). The preparation technique was checked by analysis in the Battelle Laboratory, and standards were then supplied to other labora4ories to use as guides in appraising the performance of recently constructed analytical apparatus. A frequent difficulty in many roundrobin programs is that samples are taken from heterogeneous materials and submitted to various laboratories. Also, the presumed standard samples are not 1 Present address, Glendale Laboratory, International Business Machines, Inc., Endicott, N. Y.
72
ANALYTICAL CHEMISTRY
furmce
Open-end,
Fore-Pump
11 Exhouri
Figure 1 .
Apparatus for preparing titanium-hydrogen standards
truly standards but rather samples of unknown gas content. The concentration levels of these samples are determined by the analytical methods whose reliability they seek to establish. It is that the method presented here for standard sample preparation overcomes these difficulties.
technique a t 1300" C. (4). The rods retained from sel'en fall outside, but six of the seven results fall nithin 67,. KO explanation for the discrepancies is available. -4hot-extraction technique a t 1200' C. was used in laboratory D's analyses. Three of the 11 analyses fall within 3%, three others fall within 67,, and five VOL. 32, NO. 1, JANUARY 1960
73
are outside these limits. Again, no explanation for the variations is available, The large variations occurred at the 50-p.p.m. level. Twelve 0.1-gram standard samples were run by the spectrographic method in laboratory E. The data were presented previously ( 2 ) . As the spectrographic method relies on the use of standard samples, and because a t that time there lvere no others available, a direct comparison between hydrogen extracted and hydrogen added was impossible. However, a plot of the log of the ratio of hydrogen-to-argon line intensities, IH6j62A. to 1 6 ~ 5 2 . ~ . ,us. the log of hydrogen added gave a straight line through the data. From the line, i t was possible to compare the results of any one sample with all the others if the spectrometer readings are assumed t o
be truly representative of the hydrogen contents of the samples. This assumption may not be valid as the technique was still in the development stage. The hydrogen values from the straight line are compared with the hydrogen added values in Table I. The data show that eight of the 12 samples agree with the spectrographic line to within 3%, while one falls outside this but is within 6%. Three values fall outside these limits. I n general, this is a good indication that there is some degree of agreement between the standard samples and the spectrographic results. LITERATURE CITED
(I) Beach, A. L., Guldner, W.G., ANAL. CHEJI.31, 1722 (1959). (2) Fassel, V. A., Gordon, R.rl., Jasinski, R., Evans, M., Altpeter, L., “Recent
Developments in the Emission Spectrometric Determination of Oxygen and Xitrogen in Metals,” Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, March 3-7, 1958. (3) Fatzer, E. G., Ind. Lab. 8, 22 (1957). ( 4 ) RlcGeary, R. K, “Zirconium and Zirconium X l l ~ y s ,pp. ~ ~ 168-75, Am. SOC.for ?rletals, Cleveland, Ohio, 1953. ( 5 ) Trzeciak, BI. J., “Preparation and Analysis of Titanium-Hydrogen Standard Samples,” DMIC Memoranduni 9. Defense Metals Information Center.
RECEIVEDfor review hlay 8, 1959. Accepted -4ugust 31, 1959. Work sponsored by the Defense Net& Information Center (formerly The Titanium hletallurgical Laboratory) operated by Battelle Memorial Institute for the Department of Defense under Air Force Contract Yo. A F lS(600)-1375.
Analyses of o-Xylene Oxidation Products H. E. LUMPKIN and D. E. NICHOLSON Manufacturing Department! Research and Development Division, Humble Oil & Refining Co., Baytown, Tex. The products from catalytic oxidation of aromatic hydrocarbons are extremely complex. Extensive mass and infrared interpretive work on chromatographic and distillation fractions of the products from oxidation of o-xylene has been carried out. The spectroscopic techniques used in the identification and determination of mono- and dicarboxylic acids, the aldehyde and alcohol, diphenyl hydrocarbons, an alkyl benzyl benzoate-type ester, and the internal ester, phthalide, are discussed. Determination of molecular formulas through isotopic abundances with the mass spectrometer was very helpful in the identification of complex oxygenated compounds. Phthalide was a major component among the neutral oxidation products.
T
products from catalytic oxidation of aromatic hydrocarbons contain many types of compounds. Their identification and determination present a challenging problem from the analytical viewpoint. Although the major end products are the benzenecarboxylic acids, the presence of certain components in minor concentration is important because of their possible retarding or inhibiting effect in oxidation processes. Components of this nature are more likely to be found among the nonacidic compounds; therefore, emphasis has been placed on separated nonacidic portions of the products HE
74
0
ANALYTICAL CHEMISTRY
in detailed infrared and mass spectrometric examinations. Infrared spectra have been used by many organic chemists to identify their products and to examine them for impurities (5, 6, 14, 16). Tonomura (14) has made an infrared study of the thermal decomposition and oxidation of alkylbenzenes. Mass spectra (1, 9, 12) have also been used to study the structure of oxygenated compounds of high molecular weight. However, the time-consuming chemical methods of distillation, extraction, crystallization, titration, and derivative preparation supported by melting and boiling point and refractive index determinations have been used more extensively than spectroscopic methods in oxidation studies @,S, 5,10, I S ) . Use of physical properties alone often fails to indicate the presence of minor constituents, and for lack of specific tests, or possibly because of complexity, some fractions are identified only as residue or tar. Even though spectroscopic methods were employed, i t was necessary to have the products separated by physical methods in the initial investigations. Distillate and chromatographic fractions of aromatic oxidation products have been examined and found still to be comparatively complex mixtures in many instances. However, by applying both infrared and mass spectral methods to the separated fractions it is felt that substantially all of the products from o-xylene oxidation have been identified. The mono- and dicarboxylic acids, the
aldehlde and alcohol, diar.1 hydrocarbons, a n alkyl b e n q l benzoate-type ester, and a n internal ester, phthalide, )\-ere identified and quantitatively determined. EXPERIMENTAL
Instruments. J l a s s spectra of separated oxidation products and pure compounds were obtained on a 180°, direction-focusing mass spectrometer manufactured by Consolidated Electrodynamics Corp. (Model 21103C). The inlct system n a s modified by renioval of the metal reservoir and valve block and replacement with a n all-glass system isolated by gallium valves similar to that described previously (8). This allowed operation of the inlet system a t 320” C. Liquid samples were charged from a capillary pipet through a gallium-covered fritted disk. Solids were either melted and charged directly or dissolved in a suitable solvent. The analyses were calculated on a weight basis. Although thermal deconiposition of some of the oxygenated compounds undoubtedly occurred to some extent in the heated inlet system of the mass spectrometer, their identification from the resultant spectra was possible in most cases. Specifically, phthalic acid \!-as quantitatively converted to phthalic anhydride; therefore, analyses for the acid were made using the anhydride peaks. Infrared spectra of the calibration
