Improved method for determination of aluminum in certain nonferrous materials by use of ammonium aurintricarboxylate

Abstract

The difficulties enco untered in using existing colorimetric m ethods for t h e determination of small amounts of aluminum in nonferrous materials are d iscussed . A method is proposed for obviating these difficulties. If the m ethod is combined with a preliminary electrolysis in a m ercury cathode cell, from 0.02 t o 0.08 mg of alum inum can be determined quickly and accurately, without a colorimet er. The lise of the m ercury cathode cell and the effect of interfering substances are also discussed .

Fluorometric Determination of Aluminum in Steels, Bronzes, and Minerals

“…( 9) Judd, D. B., Ibid., 25, 24-35 (1935). (10) Kelly, K, L., Gibson, K. S., and Nickerson, Dorothy, Ibid., 33, 355-76 (1943).…”

“…The reagent which has found widest use is aluminon", ammonium aurintricarboxylate (4, 8, 15). In spite of interference by chromium, iron, beryllium, vanadium, titanium, and gallium, it has been used for colorimetrically determining from 0.04 to 1.5% of aluminum in steel (2), and for low percentages in nonferrous alloys (10). Ether extraction and mercury cathode electrolysis were used, respectively, as separations in these two procedures.…”

Separation and determination of small quantities of aluminum in steel

“…No significant errors occur if less than 50 mg of chromium remain before electrolysis. No aluminum is lost during electrolysis, according to Scherrer and Mogerman [ 12 ]. When known quantities of aluminum were added to solutions representative of those present after electrolysis, and the recommended procedure followed, quantitative results were obtained, as shown by the data in table 5 .…”

Separation and Microdetermination of Small Amounts of Aluminum

“…the interfering ions. Recent investigators have used ether extraction (4) or mercury cathode electrolyses (13) for the separation of interfering metals previous to the estimation of aluminum by the aluminon colorimetric method. Others have used organic precipitating agents such as eupferron (IS) for the separation of aluminum from such metals as iron and zirconium, or have determined aluminum by difference in the ammonia group (RsOj) precipitate (7).…”

“…Wunder and Jeanneret used sodium carbonate fusion as a means of separating relatively large amounts of alumina from the oxides of iron, titanium, and zirconium (16). As demonstrated below, it was found that the sodium carbonate fusion procedure is also an efficient means for separating very small amounts of aluminum from large amounts of interfering elements, particularly if used in conjunction with electrolysis at the mercury cathode (13).…”