Determination of total copper and zinc contents of Egyptian soils using three different methods

Summary To compare chemical methods for determining total contents of Cu and Zn in Egyptian soils, surface samples of two groups of soils from Egypt namely the alluvial and the calcareous were chosen. The samples were analyzed for the total Cu and Zn using three chemical methods namely, aqua regia, hydrofluoric acid and fusion methods. The mean values of total Cu determined by aqua regia, hydrofluoric acid and fusion methods were 58.7, 69.2, 69.4 ppm for the alluvial soils and 11.8, 13.0, 12.8 ppm for the calcareous soils respectively. The corresponding values of Zn were 138.6, 189.4, 189.8 ppm for the alluvial soils and 58.6, 89.7, 90.3 ppm for the calcareous soils. The Cu and Zn contents in the alluvial and calcareous soils, determined by the aqua regia method was lower as compared with those determined by the fusion or hydrofluoric methods.An attempt was made to use the etching of soil with aqua regia and the linear relationship, to quantitavely evaluate the total content of Cu and Zn determined with hydrofluoric acid or fusion methods.