Determination of potassium by titrimetry

Epp's method is modified by the addition of solid calcium hydroxide to the sample solution. This simplified the procedure, increased the rapidity and lessened the sources of error. With samples containing various ions except ammonium ion, potassium (conc. of KCl 0.25 to 1.8 x 10(-2)M) was determined within 0.4% of error, by means of corrections for the existence of a large quantity of sodium chloride and for the solubility of potassium tetraphenylborate.