Chlorpyrifos-d₁₀is intended for use as internal standard for the quantification of chlorpyrifos by GC- or LC-MS. Chlorpyrifos is an organophosphate insecticide.^1,2It is lethal toA. melinus,G. ashmeadi,E. eremicus, andE. formosaadults (LC₅₀s = 0.8, 6, 12, and 17 ng/ml, respectively).¹Chlorpyrifos induces mortality inO. insidiosusadults when applied to corn, sorghum, and alfalfa plants.²It is toxic to mice (LD₅₀= 155 mg/kg).³Postnatal day 11 to 14 exposure to chlorpyrifos (3 mg/kg) decreases nest building and defense behaviors in adult female mice.⁴Formulations containing chlorpyrifos have been used in the control of insects in agriculture.

1.Prabhaker, N., Morse, J.G., Castle, S.J., et al.Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pestsJ. Econ. Entomol.100(4)1053-1061(2007) 2.Al-Deeb, M.A., Wilde, G.E., and Zhu, K.Y.Effect of insecticides used in corn, sorghum, and alfalfa on the predator Orius insidiosus (Hemiptera: Anthocoridae)J. Econ. Entomol.94(6)1353-1360(2001) 3.Guo, J.-X., Wu, J.J.-Q., Wight, J.B., et al.Mechanistic insight into acetylcholinesterase inhibition and acute toxicity of organophosphorus compounds: A molecular modeling studyChem. Res. Toxicol.19(2)209-216(2006) 4.Venerosi, A., Cutuli, D., Colonnello, V., et al.Neonatal exposure to chlorpyrifos affects maternal responses and maternal aggression of female mice in adulthoodNeurotoxicol. Teratol.30(6)468-474(2008)