Vegetable digestion - Huaqiang Electronic Network

Vegetable digestion equipment: Gdana DS-360 graphite digestion reagent: 1. Nitric acid (HNO ₃ ): ρ = 1.42g / mL, excellent grade 2. Perchloric acid (HClO ₄ ): ρ = 1.68g / mL , pure grade pure steps: 1. Take the edible part of fresh vegetables, wash it with tap water and double distilled water in turn, dry the surface water, put it in the oven at 100-105 °C constant temperature, take it out and grind it. In the dryer. 2. Weigh 0.5 g of the ground vegetable sample into the digestion tube, plug the perforated tube plug, add 15 mL of mixed acid HNO ₃ + HClO ₄ (4+1), and let stand overnight. 3. Set the temperature of the digestion device to 70--80 °C, insert the digestion tube into the digestion hole, and let the acid reflux to clean the inner wall of the tube, so that the sample is completely mixed with the acid for 10 minutes. 4. Warm up to 100 °C. At this time, the digestion tube is filled with reddish brown smoke, and the sample is digested for 30 minutes. If the sample is not completely digested, add 5 mL of mixed acid HNO ₃ + HClO ₄ (4+1) after cooling, and reset the temperature. Continue to digest until the sample solution is clear and pale yellow.