Determination of Micro Impurity Element Potassium in Sodium Metavanadate by ICP-OES

Abstract

The sodium metavanadate samples are digested completely by hydrochloric acid and nitric acid (VHCl: VHNO3=5:1), and then made a directly determination of micro element potassium of 0.010 to 1.0% by inductively coupled plasma atomic emission spectrometry (ICP-OES). In the coexistence medium of 42% vanadium and 20% sodium, the method systematically investigated the matrix effects, spec tral interferences, background effects and other interference factors, and a concluded was made: the matrix elements vanadium and sodium do not produce spectral interference in the determination of micro potassium, the matrix effect of vanadium and background noise enhanced the detection sig nal of potassium spectral lines, however, the matrix effects of sodium weakened the signal of potassium . In the high concentrations of vanadium and sodium coexistence medium system, the ove rall matrix effect still raised up the detection signal of potassium analysis lines and the background noise. Therefore, the test have taken the preferred analysis spectral lines, background correction region and ICP spectrometer parameters and other testing measures, and through comprehensive application of the matrix matching and synchronization background correction methods to eliminate interference in determination of the micro potassium that caused by the high content of vanadium and sodium coexist matrix. The results show: Detection limit is 480μg/L (766.490nm) or 480μg/L (769.896nm); Background equivalent concentration is 200μg/L (766.490nm) or 210μg/ L (769.896nm); RSD ≤ 2.72% (766.490nm) or RSD≤ 3.60% (769.896nm); Recovery rate is between 95.0% and 107.5%.