X-ray fluorescence determinatin of trace elements in soil

Trace elements in soil are quantified by direct X-ray fluorescence method. Gallium is used an internal standard to compensate for variations in sample matrix, instrumental operating characteristics, and sample preparation. At the 50-mg kg^?1 level, V, Cr, Ni, Cu, Zn and As can be determined within a precision and accuracy of ± 20% or less. Sample prepartion is less elaborate than for some other methods.