94- 74-6 MCPA

MCPA, l-methyl-A-chlorophenoxyacetic acid, Methoxone, CgH ClOj. Made by chlorination of o-cresol followed by reaction with chloroethanoic acid. While crystals, m.p. 118-119 C. As usually obtained, crude MCPA contains both 4- (60%) and 6- (40%) chloro-isomers, and is a light brown solid. Selective weedkiller. 

MCPA [94-74-6] (4-chloto-2-methylphenoxy)acetic acid CgHgClO ... 

It is interesting to note that many of the agricultural pesticides exceed 0.1 /tg D S but very few have been recorded as failing these operational standards. In 1993 there were no failures in environmental waters for isoproturon, chlorotoluron, mecoprop or MCPA. 

McNeil Consumer Healthcare Company, 234, 238 MCP Group, See Mining Chemical Products Ltd. (UK), 212 MCP Metalspecialties Inc., 212, 238 MCPA, 87... 

TARGET , dicamba,+ MCPA+ mecoprop, 125 Tate Lyle Group Pic, 213 Tatneft, 198... 

The unripened fruit of the akee tree contains hypoglycin, a rare amino acid (Figure 24.14). Metabolism of hypoglycin yields methylenecydopropylacetyl-CoA (MCPA-CoA). Acyl-CoA dehydrogenase will accept MCPA-CoA as a substrate,... 

Figure 13.15 Chromatograms obtained by on-line ti ace enrichment of 50 ml of Ebro river water with and without the addition of different volumes of 10% Na2S03 solution for every 100 ml of sample (a) blank with the addition of 1000 p.1 of sulfite (b) spiked with 4 p.g 1 of the analytes and 1000 p.1 of sulfite (c) spiked with 4 p.g 1 of the analytes and 500 p.1 of sulfite (d) spiked with 4 p.g 1 of the analytes without sulfite. Peak identification is as follows 1, oxamyl 2, methomyl 3, phenol 4, 4-niti ophenol 5, 2,4-dinitrophenol 6, 2-chlorophenol 7, bentazone 8, simazine 9, MCPA 10, atrazine. Reprinted from Journal of Chromatography, A 803, N. Masque et ai, New chemically modified polymeric resin for solid-phase extraction of pesticides and phenolic compounds from water , pp. 147-155, copyright 1998, with permission from Elsevier Science.

In marked contrast to hydrophobic compounds, more polar ones tend to be less adsorbed and to reach relatively high concentrations in soil water. Phenoxyalkanoic acids such as 2,4-D and MCPA are good examples (Figure 4.3). Their half-lives in soil are measured in weeks rather than years, and they are more mobile than OC insecticides in soils. When first applied they are lost only slowly. After a lag period of a... 

Distorted growth patterns 2,4-D, MCPA, CMPP, and Hassall (1990) ... 

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