Digestion Method of Closed Microwave Sample Preparation System for Rice, Corn Flour and Flour

1、 Scope of application

The method provides a microwave digestion solution for grains (rice, corn flour, flour, etc.).

2、 Dissolving method

1. Weigh 0.250g of the test sample and place it into the dissolution cup of the main control tank.

2. Add 10ml nitric acid (65%~68%, AR) to the microwave digestion tank, cover the tank and tighten the lid.

3. Prepare parallel samples and a blank sample using the same method (containing the same amount of reagent and 0.250ml of secondary distilled water or deionized water), and it is prohibited to select the blank sample as the main control tank.

4. Install the main control tank and connect the temperature sensor; Then evenly place the remaining tanks into the seat of the turntable.

5. Close the door of the microwave oven, select the microwave digestion (temperature control) mode, and run the microwave digestion program with the following settings:

Note: This experiment involves 6 tank samples, and the number of tank samples can be increased as needed.

7. After the digestion is completed, wait for the tank to cool down to within 100 ℃ in the furnace chamber, then remove the digestion tank in sequence and remove the temperature sensor.

8. After the temperature of the jacket cools to room temperature, loosen the vent valve in the fume hood to release the pressure, open the dissolution cup, transfer the sample digestion solution to a 50ml volumetric flask, and use deionized water or distilled water to transfer the cleaned solution from the inner wall and lid of the dissolution cup to the volumetric flask, and make up to 50ml

9. Due to testing requirements, it is recommended to increase the sampling volume and use appropriate methods to prepare the front areaReason.