Accelerated dynamic leaching of iron from soil with on-line derivatization and integrated concentration-detection

A module for continuous high pressure-temperature leaching is proposed. The overall approach involves the coupling of an extractor with a continuous-flow manifold where the analyte forms a complex with SCN(-), which is driven to a flow-cell packed with a suitable material for retention and continuous monitoring of this process which in turn is a way for indirect monitoring of the leaching kinetics. The approach has been used for the determination of iron in soil after leaching and derivatization. The sensitivity of the method (ng level) and the short time required (only 15 min versus 24 h for leaching and 30 min for the measurement step required by the conventional method), together with its precision (RSD less than 9%) makes this method an excellent alternative to the conventional procedure.