RAPID METHOD FOR IONOMETRIC DETERMINATION OF CONTENT OF POTASSIUM IN LEAVES AND DISTRIBUTION THEREOF ON PHYSIOLOGICAL POOLS

摘要

FIELD: chemistry.;SUBSTANCE: leaf of an analysed plant is taken and divided in half on the middle lamella. One part of the leaf is used to determine dry mass of the leaf. The second part is cut into 1-1.5 cm parts and soaked for one hour in 30 ml of 0.01 M CaCl₂ solution. Further, concentration of potassium in the extract is determined using a potassium electrode, which shows content of potassium in the conducting system of the leaf. After 4-minute boiling of the same extract with leaves and cooling to the initial temperature, content of potassium is determined again using the potassium electrode which shows total content of potassium. The value obtained on the device, expressed in mg K/l, is recalculated as a percentage of K₂O of the mass of the leaf by multiplying with a coefficient of 0.003615 and dividing by the dry mass of the leaf, expressed in grams. Further, the obtained data are used as information on total content of potassium in the leaves, which enable to obtain content of potassium in the metabolic pool by subtracting content of potassium in the apoplast pool from the obtained amount of potassium.;EFFECT: determining content of potassium in the apoplast and symplast pools.;1 tbl