261-266A
new spectrophotometric method was developed for the quantification of potassium
in the culture broth supernatant of K-solubilizing bacteria. The standard curve
of potassium with the new method, which is based on the measurement of cobalt,
showed a regression coefficient (R2) of 0.998. The quantification
values of potassium obtained with flame photometric method and the newly
developed method showed a significant correlation (r) of 0.978. The new method
depends on the precipitation of sodium cobaltinitrite with solubilized
potassium in liquid medium as potassium sodium cobaltinitrite, which develops
bluish green colour by the addition of conc. HCl. The intensity of developed
colour can be recorded at 623 nm. This method involves less number of steps, is
easy and time saving, and can be used for the reliable estimation of available
potassium in culture broth supernatant of K-solubilizing bacteria
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