trifluoride method is comparable to the vacuum fusion method for oxygen analysis of titanium and titanium alloys, and can also be used t o determine the nitrogen content. Several features of this system offer excellent possibilities for further study. The use of a zero blank eliminat>es any error due to varying blank values during the course of an analysis. Also, the apparatus can be modified for any range of gas values by changing the calibrated receiver. The bromine trifluoride system also offers possibilities for the determination of gases in metals 11hich is difficult by other methods. For example, the sulfur group, sulfur, selenium, and tellurium, cannot be tolerated in the vacuum fusion procedure, because these elements poison the cupric oxide-ceric oxide catalyst in this apparatus. Also, a limited number of silicon samples have bcrn analyzed by this method ivith good agreement with vacuum fusion results. This system could be useful in the analysis of lead and uranium-bismuth alloys. Hoekstra and Katz ( I O ) have suggested possible modifications to increase the number of compounds which can be analyzed. Further work u-ith othw metals and alloy systems should be important to any analytical laboratory involved in metals research and evaluation. I n future work performed by this
technique two important modifications are possible. Other metals such as Monel or copper should be considered t o replace the all-nickel reaction system. These metals are more economical to use and are much more easily tooled. The measuring system would be more accurate if the calibrated manometer (Figure 1) were replaced by a Kesslor 3-stage circulating pump with a modified McLeod gage, such as the one on the Sational Research Corp.'s vacuum fusion apparatus. The circulatory pump with a Toepler pump would be more efficient in quantitatively transferring the evolved gases, and the use of the McLeod gage for volume and pressure measurements would reduce the reading error by one half. ACKNOWLEDGMENT
The authors are indebted to the Waterton-n Arsenal and the Chicago Ordnance District for their sponsorship of this investigation, and to Samuel Vigo of the Watertown Arsenal for encouragement and guidance. They thank Harold Combs and Myron Hillmer of the Armour Research Foundation for the Kjeldahl nitrogen and vacuum fusion data, and H. R. Hoekstra and J. J. Katz of the Argonnr Sational Laboratory for their generous assistance throughout.
LITERATURE CITED
(1) Albrccht, W. M., Mallett, 31. \i7., ANAL.CHEM.26,401 (1954). (2) Aldrich, J. J., Chase Brass & Copper Co., Inc., Xaterbury 20, Conn., personal
communication. (3) Bennett, S. J., Covington, L. C., *%NSL. CHEV. 30,363 (1958). (4) Codell, Maurice, Norwitz, George, I b d , 27, 1083 (1955). (5) Corbett, J. A., ilnalyst 76, 652-7 (1951). (6) Derge, Gerhard, J . Metals 1,31(1949). (7) Dupraw, W. A., O'Neill, H. . J., Symposium on Analysis of Titanium and Titanium Alloys, 128th Meeting, ACS, llinneapolis, hlinn., 1955. (8) Emelbus, H. J., Woolf, A. A., J . Chem. SOC.1950, 164. (9) Fassel, V. A,, Gordon, W. A , A x . 4 ~ . CHEM.30, 179 (1958). (10) Hoekstra. H. R.. Katz. J. J., Ibid.. ' 25, 1608 (1953). ' (11) Schnizlein, J. G., Argonne Kational Laboratories, Lemont, Ill., personal communication. (12) Sheft, Irving, Martin, A. F., Iiatz, J. J . . J .
