Mercury Cathode Method for Determining Small Amounts of Titanium

THE POLAROGRAPHIC DETERMINATION OF TITANIUM IN STEELS AND NICKEL-BASE ALLOYS. R. P. Graham , A. Hitchen , J. A. Maxwell. Canadian Journal ...
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ANALYTICAL EDITION

February 15, 1942

TABLE 11. ANALYSES O F COMMERCL4L Total Sulfur (Bomb Method)

Sample

PRODUCTS Free Sulfur .oposed Method)

%

70 Topped Mexican crude0 Venezuela crudea SDecial narJhthenic Diesel lubri-eating &l SAE 30a Special naphthenic Diesel lubricatine oil S A E 400 Special-naphthe&-motor oil4 Special cutting oil A Special cutting oil B Sulfurized gear oil A Sulfurized gear oil B Sulfurized mineral oil Sulfurized f a t t y oil

4.0 2.0

2.18 1.90 2.42 3.08 2.06 1.30 2.25 1.03 10.01

0.00 0.00

0.00

0.00 0.00 0.97-1.01 1.09-1.11 0.56-0.58 1.27-1.33 0.52-0.56 0.00

109

utility of the method for oils containing added soaps, halogenated materials, etc., has not been completed. However, tests made with mineral oils containing either 5 per cent of lead naphthenate, 5 per cent of lead linoleate, unsaturated acids (5 per cent oleic acid), unsaturated hydrocarbons (30 per cent pine oil), or large amounts of oxidized oils from engine tests or laboratory oxidation tests (contain peroxides) showed no significant interference by these substances.

Acknowledgment

5 These products are possessed of their high total sulfur content, naturally.

The authors acknowledge their appreciation of the assistance of F. C. Gast, L. Donn, and Karl Uhrig in the development and testing of this method.

Literature Cited combined sulfur. The results of typical analyses are given in Table I. A variety of commercial petroleum products of relatively high total sulfur content were analyzed and consistent results for free sulfur obtained. Typical of these are the results in Table 11. The method has been used for over two years and proved suitable for routine testing. As little as 0.001 per cent of free sulfur has been determined with it. Investigation of the

Comay, S., IND.ENG.CHEX.,ANAL.ED., 8, 460 (1936). Garner, F. H., and Evans, E. B., J. Inst. Petroleum Tech., 71, 451 (1931). Hardman, A. F., and Barbehenn, H. E., IND. ENQ.CHEM.,ANAL. ED., 7, 103 (1935). Sivertsev, A. P.,and Meerson, E. A., Zavodskaya Lab., 9, 528 (1940). Wirth, C., and Strong, J. R., IND.ENG.CHEM.,ANAL.ED., 8, 344 (1936). PRESENTED before the Division of Petroleum Chemistry a t the 102nd Meeting of the AMERICAN CHEMICAL SOCIETY, Atlantic City, N. J.

Mercury Cathode Method for Determining Small Amounts of Titanium and Similar Metals in Alloys M. H. STELNMETZ Schenectady Works Laboratory, General Electric Company, Schenectady, N. Y.

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H E mercury cathode method of analysis as described by Lundell, Hoffman, and Bright (1, 2) has been used in this laboratory for many years. When using an average size cell and charge (0.5 gram) i t takes overnight (14 hours) before all the amalgam-forming elements are deposited in the mercury. To shorten time, when only small amounts or traces of titanium, aluminum, magnesium, or vanadium are present, a larger cell (Figure 1) has been used whereby a larger charge (5.0 gram) may be used and time shortened to 5 hours. For the larger cell, 2 to 3 amperes and 10 volts are used, as contrasted with the smaller cell using 1 ampere and 5 volts. In some cases where amounts of titanium, etc., are very small, two or three 5gram charges are run through the cell, the electrolyzed solutions are combined, and analysis is carried out by usual methods.

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Literature Cited

(1) Lundell, G. E. F., and Hoffman, J. I., “Outlines of Methods of Chemical Analysis”, p. 94, New York, John Wiley & Sons, 1938. (2) Lundell, G. E. I?., Hoffman, J. I., and Bright, H. A., “Chemical Analysis of Iron and FIGURE 1. DIAGRAM Steel”, p. 47, New York, John Wiley & OF CELL Sons, 1931.