COA
ITEM |
FAO specification |
RESULT |
Appearance |
A white to cream powder, free from extraneous impurities or added modifying agents |
White powder |
Content of A.I.，% |
≥95 |
95 |
Melting point |
154-159°C |
155℃ |
TLC |
The spot from the major component in the chromatogram prepared from the material shall have the same Rf as that from a standard diuron |
Qualified |
Free amine salts |
Maximum: 0.4% |
0.4 |
Water |
Maximum: 1.0% |
1.0 |
Mode of action:
Diuron is a systemic substituted phenylurea herbicide which canbe easily taken up from soil solution by the root system of plants and rapidly translocated into stems and leaves by the transpiration system, moving primarily via the xylem. Diuron primarily functions by inhibiting the Hill reaction in photosynthesis, limiting the production of high-energy compounds such as adenosine triphosphate (ATP) used for various metabolic processes. Diuron binds to the QB-binding niche on D1 protein of the photosystem II complex in chloroplast thylakoid membranes, thus blocking electron transport from QA to QB. This process prevents CO2 fixation and the production of ATP and other high energy compounds which are needed for plant growth. The inability to reoxidize QA promotes the formation of triplet state chlorophyll, which interacts with ground state oxygen to form singlet oxygen. Both triplet chlorophyll and singlet oxygen can extract hydrogen from unsaturated lipids, producing a lipid radical and initiating a chain reaction of lipid peroxidation. Lipids and proteins are attacked and oxidized, resulting in loss of chlorophyll and carotenoids, and in leaky membranes which cause cells and cell organelles to dry and disintegrate rapidly