Determination of Copper, Zinc, Molybdenum and Antimony in Manganese Electrolysis Solid Solute by ICP-MS with Microwave Digestion

The sample of manganese electrolysis solid solute was degested with a mixture composed of 30% hydrogen peroxide solution and nitric acid at a volume ratio of 1:1 by microwave, and the contents of 4 metal elements, copper, zinc, molybdenum and antimony with their standard electrode potential more positive than that of manganese, in the degestion solution were determined by ICP-MS. ⁶³Cu, ⁶⁶Zn, ⁹⁸Mo and ¹²¹Sb were selected as isotopes of the 4 elements; ⁴⁵Sc was added to eliminate the signal drift of copper and zinc, and ¹¹⁵In was added to eliminate the signal drift of molybdenum and antimony, respectively. The results showed that a linear relationship between mass concentration of 4 elements and their corresponding response values was kept in the range of 0.1-500 μg·L^-1, with correlation coefficients all over 0.999 9. Detection limits (3s) found were 0.003 0, 0.022 0, 0.001 0, 0.013 0 μg·L^-1 respectively. Recovery test was made by standard addition method, giving values of recovery in the range of 95.0%-103%, with RSDs (n=10) of the measured values all lower than 2.0%.