For vegetables, we first add the vegetables and diluent into the special sterile sample bag, put them into the homogenizer together, close the door, and then automatically start and complete the sample crushing and mixing. Add 30 ~ 100g of anhydrous sodium sulfate for dehydration. Shake violently with a vertical oscillator. If there is solid sodium sulfate, it means that the added anhydrous sodium sulfate is enough.

Add 0.2 ~ 0.8g carbon and decolorize. Add 70ml of dimethane, shake it on a vertical oscillator for 0.5h, use a filter, and filter it through filter paper. 35ml filtrate was measured and naturally washed to near drying in the fume hood at room temperature. The residue was ground and washed with a small amount of methylene, then transferred to a 10ml tube with stopper scale, and the volume was fixed to 2ml for later use.