Determination of potassium in potassium metavanadate by inductively coupled plasma atomic emission spectrometry
CHENG Yong
State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Pangang Group Research Institute Co., Ltd. , Panzhihua 617000, China
Abstract：After the potassium metavanadate samples were digested by hydrochloric acid and nitric acid and diluted with water to a certain volume, the content of potassium was directly measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). By controlling the sample weight and solution volume, the signal intensity of potassium was adjusted to a moderate level, in order to ensure that the method had good dynamic linear range. The matrix effect, spectral interference and background effect were tested. The effects of alkali metal ions, high vanadium matrix and argon molecules band on the transmission of solution nebulization, ICP balance and excitation, background noise and element determination were eliminated by optimizing nebulizer pressure, plasma excitation power, observation height and other operating parameters of ICP spectrometer, selecting the spectral lines and background correction position, and uniting with matrix matching and synchronous background correction. The results showed that the calibration curve showed a good linear relationship when the concentration of potassium was smaller than 40%, with the correlation coefficient of 0.999 3. Precision and recovery of the method were tested, and the relative standard deviation (RSD) found was smaller than 1.0% and the average recovery found was 103%. This method was applied to the determination of actual sample, whose results were consistent with those of potassium tetraphenylborate gravimetric method.
