Use of Microwave Oven and Nitric Acid-Hydrogen Peroxide Digestion to Prepare Botanical Materials for Elemental Analysis by Inductively Coupled Argon Plasma Emission Spectroscopy

A sample preparation method has been developed that provides a nitric acid-hydrogen peroxide digestion of plant tissue when it is heated internally by the oscillating electromagnetic field generated in a microwave oven. The total elemental concentration for barium, calcium, magnesium, manganese, phosphorus, potassium, sodium, sulfur, and zinc can be determined by inductively coupled argon plasma emission spectroscopy after sample preparation in a microwave oven. The method is rapid and provides quantitative results that agree with certified values for 4 National Bureau of Standards Standard Reference Materials: 1570 Spinach, 1572 Citrus Leaves, 1573 Tomato Leaves, and 1575 Pine Needles.