GB/T 32775-2016 in English

1. Background and significance of standard formulation

GB/T32775-2016 "Test Method for Dispersibility of Pesticides" is to standardize the dispersion performance test of water-dispersible granular pesticides during use to ensure the quality and application effect of pesticide products. The standard was proposed by the National Pesticide Standardization Technical Committee and officially implemented on January 1, 2017.

2. Comparative analysis of standard frameworks

3. Determination methods and technical requirements

Test conditions:

• Temperature controlled at 20℃±1℃
• Use standard hard water (ρ(Ca²+ + Mg²+) =342mg/L, pH=6.0~7.0)
• Equipped with special instruments: Beaker (1000mL), Electric stirrer (0~1000r/min), Stainless steel stirring rod, etc.

Determination steps:

1. Add 900mL of standard hard water to the beaker
2. Fix the stirring rod with the blade 15mm from the bottom and stir at 300r/min
3. Add 9g of sample and continue stirring for 1 minute
4. After standing for 1 minute, extract 9/10 of the suspension
5. Dry the remaining liquid and weigh the mass of the residue

Dispersibility calculation formula:

4. Implementation suggestions and precautions

Implementation suggestions:

• Prepare reagents and instruments in strict accordance with standard requirements
• Ensure that the operating environment meets the temperature and humidity requirements
• Regularly calibrate the equipment to ensure measurement accuracy

Precautions:

• When extracting the suspension, keep the tip of the glass capillary below the liquid surface
• Avoid disturbing the suspension during stirring
• Adjust the drying temperature according to product characteristics (60℃~70℃ recommended)