FIELD DETERMINATION OF MOLYBDENUM IN SOILS

A new procedure for the field characterization of the available amount of molybdenum in soil extract is described. It is based on the precon centration of the Mo(V)-SCN- complex into toluene solution of N-octyla cetamide (OAA) and subsequent heating of the extract for approximate t o 10 min at 60 degrees C over a water bath. The molar absorptivity of the complex is (3.50) x 10(4) 1 mole(-1) cm(-1) at lambda(max) 470 nm. The detection limit of the method is 4 ppb Mo. It provides a signific antly increased tolerance limit for iron (up to 1000 ppm) and is appli cable to the field characterization of Mo in soil extracts.