A simple digestion procedure for the determination of cadmium, copper, molybdenium and vanadium in plants by graphite furnace atomic absorption spectrometry and mass inductively coupled plasma spectrometry

A simple digestion procedure for the determination of Cd, Cy Mo and V in plant leaves by graphite furnace atomic absorption spectrometry and mass inductively coupled plasma was developed. Approximately to 100 mg of the previously dried plant material (200 mg of fresh material) were weighed into a 50mL plastic conical ended vial and 2mL of subboiled 65% HNO3 was added. The vial was then tightly closed and digestion performed at 80 degrees C in an oven overnight; thereafter, 2mL of 30% H2O2 were added and a light yellow solution was obtained. The volume was made up to 50mL in the vial itself and the solution was ready for analysis. Although the time required for the digestion is long, large batches are possible, and make the procedure useful for high sample throughput. As only one vessel is used for the whole procedure, contamination risks are minimized. The reagents employed are possible to be obtained with high purity, permitting low blank values and detection limits. The accuracy of the procedure was tested by the analysis of certified reference materials and good concordance was observed between experimental and certified values.