RAPID FLAME AAS DETERMINATION OF FE, CA, AND MG IN SOILS AND SEDIMENTS USING SLURRIES

A rapid procedure is described for the determination of iron, calcium, and magnesium in soil and sediment samples without a time-consuming d issolution stage. The samples were ground and then slurried in a solut ion containing 2% (v/v) and 1% (v/v) concentrated hydrochloric and hyd rofluoric acids, respectively. After a mild heating stage in a microwa ve oven, 1% lanthanum nitrate was added, and the suspensions aspirated into the flame. The use of a simple manifold based on a variable-spee d, computer-controlled pump allowed the on-line dilution of the suspen sions. Calibration with aqueous standards was carried out automaticall y.