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Titanium in steels and nickel-base alloys can conveniently be determined polarographically after electrolysis of a solution of the alloy in a n~ercur)l-cathode cell. A well-formed wave, the height of which is directly proportional to the concentration of titanium in the solution, is recorded using a supporting electrolyte that is 1.0 111 in tartaric acid, 0.5 AT in sulphuric acid, and 1.2 n/f in ammonium sulphate.The method is one of good precision arid yields values in excellent agreement with those given by umpire methods for samples of basic ope~l-hearth steel, 18-11 chromium-nickel steel, Monel, Inconel "W", and Nimonic 75 and 80. INTRODUCTIONThe only earlier work on the polarographic determination of titanium in metallurgical products appears to be that of Zan'ko, Geller, and Nilcitin (25) who proposed a method for the determination of this element in cast irons and steels. They report the determination of titanium in an acid tartrate medium after treating a solution of the alloy with aluminum dust. We have not been able to remove the interference of iron (111) by the use of this reducing agent; furthermore, the introduction of an appreciable concentration of aluminum ion is undesirable (3).Recent work in this laboratory on the polarographic deternliilation of titanium in rocks and minerals (4) has shown that very good polarographic waves for titanium are obtained in a medium containing tartaric acid, sulphuric acid, and ammonium sulphate. Interfering ions are removed by prior electrolysis of the solution in a mercury-cathode cell. The application of such a method t o the determination of titanium in steels and nickel-base alloys is discussed in the present paper. REMOVAL O F I N T E R F E R E N C E SBecause the half-wave potential for copper (11) in an acid tartrate medium is less negative than that of titanium, there is a limit to the concentration of copper that can be present without the occurrence of interference in the polarographic determination of titanium. Iron (111) also constitutes an interference (23). Electrolysis in a mercury-cathode cell is a very convenient and efficient way of removing from solution iron, copper, and nickel-and a score of other elements (12)-all without the introduction of foreign salts, and often in less time than that required by other procedures. In such an electrolysis chromium is not easily removed quantitatively but the chromium remaining in solution causes no interference in the determination of titanium, even in alloys high (20%) in chromium. The chromium content of the solution being polarographed should be Manuscript received Febrzrary 25, 1952.

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