DETERMINATION OF COBALT IN DIFFERENT OXIDATION STATES IN COBALT(II)-BASED COMPLEXONATE MICRONUTRIENT FERTILIZERS BY SPECTROSCOPIC METHODS

The study explores the impact of acid nature, pH, and an excess of Trilon B on the selectivity of determination and the ability to separately quantify Cobalt(II) and Cobalt(III) forms in micronutrient fertilizers based on cobalt(II) complexonates. Photometric methods were developed to determine the content of Cobalt(II) and Cobalt(III), as well as an atomic absorption method for determining total cobalt, for the quality control of the micronutrient fertilizer. The correctness of the developed methods was confirmed, and their metrological characteristics were calculated. The determination time is 20 minutes. The relative standard deviation does not exceed 0.02 for the photometric method and 0.03 for the atomic absorption method.