Determination of the Matrix Element Vanadium in the Potassium Metavanadate by Inductively Coupled Plasma Atomic Emission Spectrometry

The potassium metavanadate samples were digested by hydrochloric acid and diluted with water to a constant volume, then the inductively coupled plasma atomic emission spectrometry (ICP-OES) was used to directly determine the content of 10 to 45% matrix vanadium. The matrix effects, spectral interference, background noise and other interference factors in the high concentration of potassium ions coexistence system were all examined in the paper. The results showed that although the coexisting alkali metal potassium significantly increased the ICP flame, the 1g/L potassium standard solution did not produce peaks in the scanning window of analysis line which substantially coincide with the reagent blank signal line, i.e., the 28% (or 0.28g/L) potassium contained in the potassium metavanadate did not interfere with the determination. Therefore, only the standard solution of vanadium was used to draw a calibration curve without the need of potassium matrix matching. In order to obtain a wide linear range and improve the detection precision and the accuracy of the matrix element vanadium, the sample dilution ratio and ICP spectrometer detection parameters were optimized, and the suitable sensitivity spectral lines and their detection integral and background correction regional were selected, the detection signal intensity of the high concentration vanadium is effectively regulated moderate, the detection range is covered from 10 to 45%, which fully meet the need for determination of vanadium in the potassium metavanadate (qualified products containing 37% vanadium). The results also showed that the background equivalent concentration is less than 5 μg/L, the relative standard deviation (RSD) is less than 1.0%, the detection results consistent with the redox titration method. The method is simple and fast, accurate and reliable, the precision is high. The inspection cycle is 10 to 15 minutes, which is greatly shorter than the chemical titration that takes 2 to 3 hours, so that the method meet the requirements of fast-paced production site of the potassium metavanadate product quality inspection and control.