The absorptiometric determination of beryllium in iron and steel; aluminon method
1962 Volume 11 Issue 4 Pages 388-393
Details
1962 Volume 11 Issue 4 Pages 388-393
An absorptiometric aluminon method for the determination of beryllium in iron and steel has been presented by separating beryllium from ironetc. with sodium hydroxide solution and hydrogen peroxide mixture and masking the interfering elements as aluminum etc. with EDTA.
The recommended procedure is as follows : Weigh 2g sample into a 500ml flask, dissolve with 20ml of a mixed acid (HCl 1+HNO3 1) and successively with 30ml of perchloric acid, evaporate to fumes of perchloric acid, oxidize chromium to dichromate, allow to cool down to room temperature, and add approximately 50ml of water to dilute to the mark. Pipet 120ml from this solution into the mixture of 30ml of hot sodium hydroxide solution (25%) and 5ml of hydrogen peroxide (3%), transfer the solution to a 100ml. Volumetric flask after boiling for 3 min., dilute to the mark, and filter with a dried filter. Pipet 50ml from the filtrate into a 100ml beaker, just neutralize it with hydrochloric acid (1+1) and add excessive 0.25ml.
Transfer the solution to a 100ml volumetric flask, cool, add 3ml of EDTA solution (2.5%) and 15ml of aluminon-buffer solution (0.1%) with 1ml of gum arabic, and immerse the whole in boiling water for 4 min. Cool down to room temperature, dilute to the mark with water, and measure the absorbance with filter S 53. A blank test using the pure iron is followed by the same procedure. Calculate the difference of the absorbances and determine the amount of beryllium from the calibration curve.
The time required for an analysis was about 2530 min.
In addition, as compared with the aluminon method, the Eriochrome cyanine R method and the Qinalizarin method improved by the author, Eriochrome cyanine R method was found to be better than the others on the rapidity and sensitivity, although this method required more or less skill to control pH of the solution. The aluminon method was found to have an advantage in the simplicity of operation and the lower blank absorbance.
