Chlorpyrifos

Eisler, R. 2000. Chlorpyrifos. Pages 883-902 in Handbook of Chemical Risk Assessment Health Hazards to Humans, Plants, and Animals. Volume 2, Organics. Lewis Publishers, Boca Raton, Florida. 

Odenkirchen, E. W., andR. Eisler. 1988. Chlorpyrifos hazards to fish, wildlife, and invertebrates a synoptic review. U.S. Fish Wildl. Serv. Biol. Rep. 85(1.13), 34 pp. 

A United States study examined the aggregate exposures of preschool children to chlorpyrifos and its degradation product, 3,5,6-trichloro-2-pyridinol (TCP) (Morgan et al., 2005). Samples that were collected included duplicate diet, indoor and outdoor air, urine, solid and liquid food, indoor floor dust, play area soil, transferable residues, and surface wipes (hand, food preparation, and hard floor). Generally, levels of chlorpyrifos were higher than levels of TCP in all media, except for solid food samples. For these samples, the median TCP concentrations were 12 and 29 times higher than the chlorpyrifos concentrations at homes and day-care centres, 

---

Halogen Substituents. Halogen functional groups are readily replaced by nucleophiles, eg, hydroxide ion, especially when they ate attached at the a- or y-position of the pyridine ting. This reaction has been exploited in the synthesis of the insecticide chlorpyrifos [2921-88-2J (43) (42), and the insecticide tiiclopyi [55335-06-3] (44) (14,43). 2,3,5,6-Tetiachloiopyiidine [2402-79-1] reacts with caustic to form the hydioxylated material [6515-38-4], which then can be used to form (44) and (43). 

The piedominant use of P-picoline (3) is as a starting material for agrochemicals and pharmaceuticals. For example, it is used to make insecticides such as chlorpyrifos (43), food additives such as niacin (27) and its amide (26), and herbicides such as fluazifop-butyl [69806-50-4] (63). 

The sfe of chlorpyrifos methyl from wheat followed by on-line Ic/gc/ecd has been investigated (93). Extraction profiles were generated to determine the maximum analyte recovery and the minimum extraction time. Using pure CO2, a 65% recovery of chlorpyrifos methyl spiked onto wheat at 50 ppb was reported. When 2% methanol was added to the CO2, the recovery from a one gram sample averaged 97.8% (n = 10, 4.0% RSD). 

DTBP see DI-tert-BUTYL PEROXIDE DURSBAN see CHLORPYRIFOS... 

Long Island Regional Poison Drug hiformation Center, 315 Lonza Group AG, 204 Lords Chemicals Ltd., 173 LORSBAN , chlorpyrifos, 84... 

Figure 5.2 Electrospray-MS-MS signal response of seven of the pesticides versus eluent flow rate, based on (a) peak area, and (b) peak height , atrazine , simazine , diuron x, isoproturon , chlorfenvinphos , chlorpyrifos O, alachlor. Reprinted from 7. Chromatogr., A, 937, Asperger, A., Efer, J., Koal, T. and Engewald, W., On the signal response of various pesticides in electrospray and atmospheric pressure chemical ionization depending on the flow rate of eluent applied in liquid chromatography-mass spectrometry , 65-72, Copyright (2001), with permission from Elsevier Science.

Davis DL, Ahmed AK. 1998. Exposures from indoor spraying of chlorpyrifos pose greater health risks to children than currently estimated. Environ Health Perspect 106 299-301. 

Liu J, Olivier K, Pope CN. 1999. Comparitive neurochemical effects of repeated methyl parathion or chlorpyrifos exposures in neonatal and adult rats. Toxicol Appl Pharmacol 158 186-196. 

Schimmel SC, Gamas RE, Patrick JM, et al. 1983. Acute toxicity, bioconcentration and persistence of AC 222,705, benthiocarb, chlorpyrifos, fenvalerate, methyl parathion and permethrin in the estuarine environment. J Agric Food Chem 31 104-113. 

There are marked species differences in A-esterase activity. Birds have very low, often undetectable, levels of activity in plasma toward paraoxon, diazoxon, pirimi-phos-methyl oxon, and chlorpyrifos oxon (Brealey et al. 1980, Mackness et al. 1987, Walker et al. 1991 Figure 2.10). Mammals have much higher plasma A-esterase activities to all of these substrates. The toxicological implications of this are discussed in Chapter 10. Some species of insects have no measurable A-esterase activity, even in strains that have resistance to OPs (Mackness et al. 1982, Walker 1994). These include the peach potato aphid (Myzus persicae Devonshire 1991) and the... 

---