GB/T 32777-2016Test method of degree of dissolution and solution stability for pesticides (English PDF)

3.1 Method Summary

The samples were dissolved in standard hard water at 30 ° C, inverted 15 times, allowed to stand for 5 min, filtered through a 75 µm test sieve, and the residue was sieved

Material. Solution stability The solution was allowed to stand for 18 h and then filtered again with a 75 µm test sieve.

3.2 Instruments and reagents

Standard sieve. pore size 75µm, diameter 76mm.

Scale cylinder. glass, with plug, 0mL ~ 250mL scale distance between 20cm ~ 21.5cm, 250mL scale line and the bottom of the plug

The distance is 4cm ~ 6cm.

Standard hard water. Standard hard water [rho (Ca2 Mg2) = 342 mg/L], 30 ° C ± 3 ° C according to the method described in GB/T 5451-2001

2 ° C.

3.3 Preparation of sample solution

Add 2/3 of the preheated 30 ° C standard hard water in a 250 mL graduated cylinder and add a quantity of sample (the number of samples should be

Recommended the highest use of the same concentration, not less than 3g), plus standard hard water to the mark, cover the plug. Standing for 30s, hand down the cylinder 15 times (180 °), reset, reverse, reset the time used no more than 2s.

The sample solution in the graduated cylinder was allowed to stand for 5 min ± 30 s and poured into a constant weight 75 µm test sieve. The filtrate was collected in 500 mL

Beaker, left for the next step. Wash the graduated cylinder with 20 mL of distilled water 5 times, all the insoluble material quantitative transfer to the screen, abandoned to wash

The test sieve was dried to constant weight at 60 ° C and weighed (accurate to 0.0001 g).

3.5 after 18h test

After standing for 18 h, the solution in the beaker was filtered through a 75 µm test sieve and the test sieve was washed with 100 mL of distilled water. Will test

The sieve was dried to constant weight at 60 ° C and weighed (accurate to 0.0001 g).