Pesticides Glyphosate 75.7% WDG

Glyphosate

Herbicide

Classfication Glycine derivative

NOMENCLATURE

glyphosate

Common name glyphosate (BSI, E-ISO, (m) F-ISO, ANSI, WSSA, JMAF)

IUPAC name N-(phosphonomethyl)glycine

Chemical Abstracts name N-(phosphonomethyl)glycine

CAS RN [1071-83-6] EEC no. 213-997-4 Development codes MON-0573 (Monsanto); CP 67573 (Monsanto)

glyphosate-ammonium

CAS RN [40465-66-5] monoammonium salt; [69254-40-6] diammonium salt; [114370-14-8] unspecified ammonium salt Development codes MON 8750 (Monsanto)

glyphosate-isopropylammonium

CAS RN [38641-94-0] EEC no. 254-056-8 Development codes MON 0139 (Monsanto); MON 77209 (Monsanto)

glyphosate-sodium

CAS RN [34494-03-6] Development codes MON 8722 (Monsanto)

glyphosate-trimesium

IUPAC name trimethylsulfonium N-(phosphonomethyl)glycinate

Chemical Abstracts name N-(phosphonomethyl)glycine trimethylsulfonium salt

Other names sulfosate CAS RN [81591-81-3] Development codes SC 0224; ICIA0224 (ICI)

PHYSICAL CHEMISTRY

glyphosate

Composition Tech. is 95% pure. Zwitterion structure (P. Knuuttila & H. Knuuttila, Acta Chem. Scand., 1979, 33, 623). Mol. wt. 169.1 M.f. C₃H₈NO₅P Form Colourless crystals. M.p. 189.5°C B.p. Decomp. >200 °C V.p. 1.31×10^-2 mPa (25 °C) KOW logP <-3.2 (pH 2-5, 20 °C), (OECD 107; EEC A8) Henry <2.1×10^-7 Pa m3 mol^-1 S.g./density 1.705 (20 °C) Solubility In water 10.5 g/l (pH 1.9, 20 °C). Insoluble in common organic solvents, e.g. acetone, ethanol and xylene. The alkali-metal and amine salts are readily soluble in water. Stability Glyphosate and all its salts are non-volatile, do not photochemically degrade and are stable in air. Glyphosate is stable to hydrolysis at pH 3, 6 and 9 (5-35 °C). pKa 2.34 (20 °C), 5.73 (20 °C), 10.2 (25 °C) F.p. Not flammable

glyphosate-ammonium

Composition Tech. is 95.2% pure. Mol. wt. 186.1 M.f. C3H11N2O5P Form Odourless, white powder. M.p. Decomp. >190 °C, without melting V.p. 9×10^-3 mPa (25 °C) KOW logP <-3.7 Henry 1.16×10^-8 Pa m³ mol^-1 (calc.) S.g./density 1.433 (22 °C) Solubility In water 144±9 g/l (pH 3.2). Essentially insoluble in organic solvents. Stability Stable over 5 days at 50 °C (pH 4, 7 and 9). pKa See isopropylammonium salt F.p. Not flammable

glyphosate-isopropylammonium

Composition As a wet cake, contains c. 62% w/w isopropylamine salt, c. 35% water. Mol. wt. 228.2 M.f. C6H17N2O5P Form Odourless, white powder. M.p. Occurs in 2 steps, 143-164 °C and 189-223 °C B.p. Decomposes without boiling V.p. 2.1×10^-3 mPa (25 °C) KOW logP = -5.4 Henry 4.6×10-¹⁰ Pa m³ mol^-1 (25 °C, calc.) S.g./density 1.482 (20 °C) Solubility In water 1050 g/l (25 °C, pH 4.3). In dichloromethane <0.5, methanol 19.86 (both in g/l, 20 °C). Stability Stable 5 days at pH 4, 5, and 9 (50 °C). pKa 5.77±0.03, 2.18±0.02 (20±2 °C), (OECD 112)

glyphosate-sodium

Mol. wt. 191.1 M.f. C3H7NNaO5P Form Odourless, white powder. M.p. Decomp. >260 °C V.p. 7.56×10^-3 mPa (25 °C) KOW logP <-3.02 Henry 4.27×10^-9 Pa m³ mol^-1 (calc.) S.g./density 1.622 (20 °C) Solubility In water 335?1.5 g/l of solution (or 414±51.8 g/l of water) (pH 4.2, 20 °C). Stability Stable over 5 days at 50 °C (pH 4, 7 and 9).

glyphosate-trimesium

Mol. wt. 245.2 M.f. C6H16NO5PS Form White solid. M.p. Decomp. 150 °C V.p. <0.01 mPa (20 C) KOW logP = -2.9 Henry <2±10^-9 Pa m³ mol^-1 (calc.) S.g./density 1.42 Solubility In water >1000 g/l. In acetone, chlorobenzene, ethanol, kerosene, xylene <5 (all in g tech./l).

APPLICATIONS

Biochemistry Inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme of the aromatic acid biosynthetic pathway. This prevents synthesis of essential aromatic amino acids needed for protein biosynthesis. Mode of action Non-selective systemic herbicide, absorbed by the foliage, with rapid translocation throughout the plant.

Inactivated on contact with soil. Uses Control of annual and perennial grasses and broad-leaved weeds, pre-harvest, in cereals, peas, beans, oilseed rape, flax and mu