Method performance of K2O analysis in flake potassium fertilizer using flame photometer

Potassium is the only monovalent cation-shaped element that plants need and is the third major nutrient for plant growth. This study aims to determine the level of K2O in potassium chloride flake fertilizer using a flame photometer which is a development of the Indonesian National Standard method 02-2805-2005, so it needs to be validated to prove that the method used is as intended. The results showed that the K2O levels in each validation parameter showed results that met the requirements. Linearity value in standard solution of potassium 0; 1; 2; 3; 4; 5; 10; 15 and 20 ppm obtained the coefficient of determination (R2) of 0.9966. The precision value obtained is less than 2/3% CV Horwitz so the repetition of the sample can be said to be good. The accuracy value of the potassium chloride fertilizer obtained from 98.64% - 100.95% is a good result because it is in the range of 98% - 102% this value is included in the range of acceptance requirements.