SPECTROPHOTOMETRY DETERMINATION OF IRON IN AGRICULTURAL SOILS

2,2'-dipyridilketona picolinoyhidrazone (dPKPH) react with iron (II), in aqueous ethanolic solution, to produce a green 2:1 complex (lambda( max) = 700 nm, epsilon = 7,0 x 10(3) 1 mol-1 cm-1). The method present attractive sensitivity and high selectivity, and has been applied to determination of iron in agricultural soils. The extraction into chlor oform of green complex is possible (lambda(max) = 700 nm, epsilon = 6, 7 x 10(3) l Mol-1 cm-1); in this manner the method is more selective a nd potentially more sensitive.