Experimental analysis of herbicide residues in rice
Experimental analysis of herbicide residues in rice
Residues in agricultural fields have also attracted the attention of agrochemists because some herbicides can cause damage to the following crop during application, resulting in reduced yields. Source: Food Safety Testing Technology (Chemical Industry Press)
Operation method
Technique for analyzing herbicide residues in rice
Materials and Instruments
Rice Move 1. Pre-treatment For more product details, please visit Aladdin Scientific website.
Acetone-water CH2Cl2-cyclohexane n-hexane
Filter flask; gel chromatography column
Take 20 g of sample, add 200 mL of acetone-water (7 + 3), shake for 30 min, filter, and concentrate the filtrate to dryness. Add 150 mL of 10% NaCl and 2 x 50 mL of CH2CI2, shake, and stratify; the CH2Cl2 layer was dehydrated with anhydrous sodium sulfate and concentrated to dryness. Add CH2Cl2cyclohexane (1 + 1) 20 mL, keep at -40 ℃ for 50 min, centrifuged at 20,000 r/min for 15 min, remove the supernatant and concentrate to dryness. Add CH2Cl2-cyclohexane (1 + 1) 20 mL to dissolve and then filtered through 0.45 un membrane. 2. Purification conditions
Gel column: ENVIROSEP-ABC (Phenomenex) 350 mm × 21.2 mm; pre-column: ENVIROSEP-ABC (Phenomenex) 60 mm × 21.2 mm; mobile phase: CH2Cl2-cyclohexane (1 + 1) at a flow rate of 5 mL/min; pre-drenching of 65 mL, collection of 80 mL in elution, 10 mL in column wash. The eluent was concentrated to dryness. Concentrate the eluate to dryness, add 10 mL of acetone, remove 3 mL, (equivalent to 3 g of sample), concentrate to dryness, add 10 mL of hexane. The SAX (upper) + PSA (lower) column was first pre-washed with 5 mL acetone and 10 mL hexane, then the sample solution was added and washed with 10 mL hexane, and finally eluted with 20 mL of hexane-acetone (2 + 1), concentrated and then fixed with 3 mL of acetone, and determined by GC-MS. 3. GC-MS conditions Detector MSD, interface 280 ℃, SIM mode, selected ions are shown in Table 2- 11.
