Specification :

Imidacloprid

Common name: imidacloprid; imidaclopride
IUPAC name: 1-( 6-chloro-3-pyridylmethyl) -N-nitroimidazolidin-2-ylideneamine
Chemical Abstracts name: 1-[ ( 6-chloro-3-pyridinyl) methyl] -N-nitro-2-imidazolidinimine
CAS RN: [ 138261-41-3]

PHYSICAL CHEMISTRY
Mol. wt.: 255.7; M.f.: C9H10ClN5O2; Form: Colourless crystals, with a weak characteristic odour. M.p.: 144 ° C; V.p.: 4x10-7 mPa ( 20 ° C) ; 9x10-7 mPa ( 25 ° C) . KOW: logP = 0.57 ( 21 º C) . Henry: 2x10-10 Pa m3 mol-1 ( 20 ° C, calc.) S.g./ density: 1.54 ( 23 º C) . Solubility: In water 0.61 g/ l ( 20 º C) . In dichloromethane 55, isopropanol 1.2, toluene 0.68, n-hexane 5000 mg/ kg. Non-irritating to eyes and skin ( rabbits) . Not a skin sensitiser.
Inhalation: LC50 ( 4 h) for rats > 5323 mg/ m3 dust, 69 mg/ m3 air ( aerosol) .
NOEL: ( 2 y) for male rats 100, female rats 300, mice 330 mg/ kg diet; ( 52 w) for dogs 500 mg/ kg diet.
ADI: 0.057 mg/ kg b.w.
Other: Not mutagenic or teratogenic.
Toxicity class: WHO ( a.i.) II; EPA ( formulation) II

ECOTOXICOLOGY
Birds: Acute oral LD50 for Japanese quail 31, bobwhite quail 152 mg/ kg. Dietary LC50 ( 5 d) for bobwhite quail 2225, mallard ducks > 5000 mg/ kg.
Fish: LC50 ( 96 h) for golden orfe 237, rainbow trout 211 mg/ l.
Daphnia: LC50 ( 48 h) 85 mg/ l.
Algae: ErC50 for Pseudokirchneriella subcapitata > 100 mg/ l.
Bees: Harmful to honeybees by direct contact, but no problems expected when not sprayed into flowering crop or when used as a seed treatment.
Worms: LC50 for Eisenia foetida 10.7 mg/ kg dry soil.

ENVIRONMENTAL FATE
Animals: After oral administration of methylene-14C- and 4, 5-imidazolidine-14C-labelled imidacloprid to rats, the radioactivity was quickly and almost completely absorbed from the gastro-intestinal tract and quickly eliminated ( 96% within 48 hours, mainly via the urine) . Only c. 15% was eliminated as unchanged parent compound; the most important metabolic steps were hydroxylation at the imidazolidine ring, hydrolysis to 6-chloronicotinic acid, loss of the nitro group with formation of the guanidine and conjugation of the 6-chloronicotinic acid with glycine. All metabolites found in the edible organs and tissues of farm animals contained the 6-chloronicotinic acid moiety. Imidacloprid is also quickly largely eliminated from hens and goats.
Plants: Metabolism was investigated on rice ( after soil treatment) , maize ( seed treatment) , potatoes ( granule or spray application) , aubergines ( granules) and tomatoes ( spray treatment) . In all cases, imidacloprid is metabolised by loss of the nitro group, hydroxylation at the imidazolidine ring, hydrolysis to 6-chloronicotinic acid and formation of conjugates; all metabolites contained the 6-chloropyridinylmethylene moiety.
Soil/ Environment: In lab. studies, the most important metabolic steps were oxidation at the imidazolidine ring, reduction or loss of the nitro group, hydrolysis to 6-chloronicotinic acid and mineralisation; these processes were strongly accelerated by vegetation. Imidacloprid shows a medium adsorption to soil. Column leaching tests ( with prior ageing) with a.i. and various formulations showed that imidacloprid and soil metabolites are to be classified as immobile; leaching into deeper soil layers is not to be expected if imidacloprid is used as recommended. Stable to hydrolysis under sterile conditions ( under exclusion of light) . Environmental DT50 c. 4 h ( calc., based on tests of direct photolysis in aqueous solutions) . Besides sunlight, the microbial activity of a water/ sediment system is an important factor for the degradation of imidacloprid.