Abstract
Manganese thiocyanate-complex is formed when thiocyanate ion is added to a sample solution containing trace amont of manganese.
The complex can be extracted with a solution of trioctylmethylammonium chloride(capriquat) in ethyl acetate.
The resulting organic phase can be used for the atomic absorption analysis.
To a sample solution containing up to 12μg of manganese was added ammonium thiocyanate to make the concentration 0.8M, and then 5 ml of 10% ammonium acetate solution was added to adjust the pH of the solution to 6.0. The total volume was made up to 50 ml with water. The solution was extracted with 10 ml of 5 vol% solution of capriquat in ethyl acetate.
By using the organic phase, the absorbance in the airacetylene flame was measured at 2794.8 Å.
A calibration curve obtained was straight up to 12μg of manganese content. The standard deviation obtained from 5 runs was 1.02% in the determination of 5μg of manganese.
The presence of more than 100 μg of Fe(III) gave a positive error, but other ions do not interfere the determination.
By applying the present method to the determination of manganese in river water, satisfactory results were obtained.
This method can be used for highly sensitive and highly accurate determination of manganese.
