MCPA Acetic

Acetic acid, ((4-chloro-o-tolyl) oxy)-. See MCPA Acetic acid, chromium (3+) salt. See Chromium acetate (ic)... 

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

Saltar and Paasivirta [155] have described a method for the analysis in soils of MCPA (4-chloro-2-methyl phenoxy acetic acid) and two of its main metabolites, 4-chloro-o-cresol and 6-chloromethyl catechol by gas chromatography of their pentafluorobenzyl derivatives (Fig. 9.12). After derivitization of the residue extract, a clean-up procedure was applied. The best recoveries of compounds from soil were obtained when the extraction was performed by shaking with ether-acetone-heptane-hexane (2 1 1 1) from acidified soil and when the clean-up was done by thin layer chromatography (Table 9.17). Detection limits were in the range 20-25ng absolute. 

Waliszewski and Szynczynski [158] have described a gas chromatographic method for the determination of 4-chloro-2-methyl phenoxy acetic acid (MCPA) and 2.4 chloro phenoxy acetic acid (2.4D) herbicides in soils. The chlorophenoxy acetic acid herbicides were extracted from soil... 

Many methods have been reported for the extraction of these compounds from soil. Khan [225] used acidified acetone followed by methylation with diazomethane for the simultaneous determination of 2,4-D, Dicamba and Mecoprop residues, as did Bache and Lisk [226] for Ioxynil. Abbott et al. [227] developed a method for MCPA, MCPB, 2,4-D Dichloroprop and 2,4,5-T in which dilute sulphuric acid and diethyl ether were used for extraction. Byast et al. [101] have shown that diethyl ether-chloroform-acetic acid is a suitable extractant for 2,4,5-T, 2,4-D, Dichloroprop and Dicamba [101] and saturated calcium hydroxide solution is efficient for Picloram [228] and 3,6-dichloropicolinic acid [229]. 

Dichlcax)phenoxy 2-Methyl-4-Chlcnx)phenoxyacetic Acid Acetic Acid MCPA... 

D = dichlorophenoxyacetic acid MCPA/MCPP = meta-chlorophenylpiperazine 2-methyl-4-chlorophenoxy-acetic acid... 

The determination of phosphorus after precipitation and solvent extraction as molybdophos-phoric acid (MPA) and reduction to molybdenum blue is a classical procedure,30 40 while cerium can be determined directly as molybdocerophosphoric acid (MCPA emax 7300 at 318 nm). A more selective method is to strip excess of MPA by extraction with chloroform, then to decompose residual MCPA and determine the phosphate liberated therefrom as MPA after extraction into isobutyl acetate. Alternatively AAS can be used to determine the amount of molybdenum. 

D 2,4,5-T Silvex 2.4- DB MCPA Dichlorprop Dicamba (2,4-dichlorophenoxy) acetic acid (2,4,5-trichlorophenoxy) acetic acid (2,4,5-trichlorophenoxy)propionic acid 4-(2,4-dichlorophenoxy) butyric acid (4-chloro-2-methylphenoxy)acetic acid 2-(2,4-dichlorophenoxy)propionic acid 3,6-dichloro-2-methoxybenzoic acid... 

Table V. Retention data (hRf values) for ioxynil, MCPA and flurenol on HPTLC pre-coated plates silica gel 60 (solvent system n-hexane/ethyl acetate/formic acid 40/60/0.5) and on HPTLC pre-coated plates cellulose (solvent system tert. butanol/water/25 ammonia 80/20/1)...

FIGURE 11.17 PCA loadings for raw mean-centered augmented data matrix from top to bottom, first to fifth (PCI to PC5) principal components. Compound names and abbreviations are as follows alachlor (ALA), atrazine (ATR), bentazone (BEN), biphenyl (BIF), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), (2,4-dichlorophenosy)acetic acid (2,4-D), dichloroprop (DCP), dimethoate (DIM), linuron (LIN), h-chloro-z-methyphenoxyacetic acid (MCPA), mecoprop (MEC), 4-chloro-3-methylphenol (MEP), metholachlor (MET), pen-tachlorophenol (PCP), simazine (SIM), (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), tribu-tylphosphate (TBP), 2,4,6-trichlorophenol (TCP). 

Chloroacetic acid benazolin, cloquintocet, cloxyfonac, 4 CPA, cymoxanil, 2,4 D, diethatyl, fenchlorazole, flumioxazin, fluoroglycofen, fluroxypyr, glyphosate, indol 3 yl acetic acid, MCPA, naphthoxy acetic acid, naphthylacetamide, naphthyloxy acetic acid, 2 naphthyloxy acetic acid, 2.4.5 T, triazamate, see chloro acetylchloride... 

Topalov A, Abramovic B, Molnar-Gabor D, CsANADi J, Arcson O (2001) Photocatalytic Oxidation of the Herbicide (4-Chloro-2-methylphenyl)acetic Acid (MCPA) over Ti02, J. Photochem. Photobiol. A Chem. 

In this context, we recently discovered close correlations between auxin-induced ethylene synthesis, massive accumulations of ABA in root md even more in shoot tissue and inhibition of their growth. This phenomenon, which has been reported for the first time, was demonstrated for auxin herbicides from different chemical classes (Figure 1), such as quinmerac, quinclorac, MCPA, naphthalene acetic acid, dicamba and picloram, and lAA at high concentration, in a variety of dicot species, including members of the Sola-naceae, Umbelliferae, Fabaceae, Scrophulariaceae and Brassicaceae [35, 39, 40]. ABA accumulation and concomitant epinastic effects and reduced shoot growth were also... 

SYNS AGROXONE 3 4-CHLORO-2-METHYL-PHENOXYACETIC ACID SODIUM SALT (p-CHLORO-o-TOLYLOXY)ACETIC ACID SODIUM SALT CHWASTOKS CHWASTOX DIAMET DICOTEX 80 O DIKOTEKS DIKOTEX 30 . MCPA SODIUM SALT ... 

METAXONE METHOXONE (2-METEm 4-CHLOROPHENOXY)ACETIC ACID, SODIUM SALT 2M-4KH SODIUM SALT 2M-4X Na MCPA PHENOXYLENE SODIUM (4-CHLORO-2-METHYL-PHENOXY)ACETATE SODIUM MCPA SYS 67ME... 

MCPA-Methylester (2 -methyl4 -chloropheno xy)-methyl acet ate CHj H CH3 Cl H ... 

Dichlorophenoxy)propionic acid) 2,4,5-T (2,4,5-Trichlorophenoxy acetic acid) Dicamba (3,6-Dichloro-o-anisic acid) MCPA (4-Chloro-2-methyl-phenoxy acetic acid) MCPP (2-(4-Chloro-2-methylphenoxy)propionic acid) Silvex (2-(2,4,... 

Gamar, Y. and J.K. Gaunt. 1971. Bacterial metabolism of 4-chloro-2-methylphenoxy-acetate (MCPA) formation of glyoxylate by side-chain cleavage. Biochem.. 122 527-531. 

There is a close relationship between the effect of various substances as auxins and their herbicidal effects, with some easily explained exceptions. 4-Phenoxybutanoic acids (e.g., MCPB) have no auxin effect, yet they are efficient herbicides in many plants, providing they are metabolically transformed to the corresponding acetic acid. Although MCPA is selective with toxicity mainly against broadleaves, MCPB has an even more narrow selectivity because broadleaved plants, which do not metabolize it to MCPA, are not killed. 

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