TURBIDIMETRIC DETERMINATION OF POTASSIUM BY FLOW-INJECTION ANALYSIS

A turbidimetric flow injection analytical method was developed for the determination of potassium (K) after precipitation with a 3% sodium tetraphenylboron solution at pH 9. The minimum detection limit is about 1.0 mu g K/mL. Calibration graphs of absorbance versus concentration are linear up to 20 mu g K/mL with a correlation coefficient of 0.9982. The average sampling rate is about 60 samples per hour. Relative standard deviations (s%) obtained with standard solutions of potassium are ca. 1%. Several samples of plant leaves, bottle mineral waters and serum rehydration solutions were analyzed.2781625163