A Practical Evaluation of Microwave and Conventional Wet Digestion Techniques for the Determination of Cd, Cu And Zn in Wheat Grain

Abstract

The cadmium, copper and zinc concentrations of standard reference materials and wheat samples prepared by microwave digestion and conventional nitric-perchloric acid wet digestion techniques were compared. The two digestion methods both gave acceptably consistent and reliable results for the elements studied. Some practical advantages and disadvantages of both techniques from a laboratory point of view are discussed. Despite one of the major advantages of microwave digestion being the rapidity of digestion, for large numbers of samples the combined restraints of small batch sizes, vessel cleaning time and system cost means analysis by conventional means is often as rapid and less expensive than by microwave. Furthermore analysis by conventional means is capable of achieving results of an equivalent analytical precision and accuracy.