Acetic 2,4-dichlorophenoxy

Aroclor 1248, Aroclor 1254, and Aroclor 1260. Quantitation is by comparison of chromatograms with standard concentrations of pure compounds treated in an identical manner. The phenoxy acid herbicides (2,4-dichlorophenoxy)acetic acid (2,4-D), sUvex, and (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) can be deterrnined by electron-capture detection after extraction and conversion to the methyl esters with BF.-methanol. The water sample must be acidified to pH <2 prior to extraction with chloroform. 

Chemical Designations - Synonyms Butoxyethyl 2,4-Dichlorophenoxyacetate Butyl 2,4-Dichlorophenoxyacetate 2,4-Dichlorophenoxyacetic Acid, Butoxyethyl Ester 2,4-Dichlorophenoxyacetic Acid, Isopropyl Ester Isopropyl 2,4-Dichlorophenoxy Acetate Chemical Formula 2,4-Cl2C H30CH2C00R, where R=C4H9, CjH, or CH2CH2OC4H9. 

Dichlorophenoxy acetic acid (555ng) 12/ Indole-3-acetic acid ethyl ester (445ng)... 

Ogram AV, RE Jessup, LT On, PSC Rao (1985) Effects of sorption on biological degradation rates of (2,4-dichlorophenoxy)acetic acid in soils. Appl Environ Microbiol 49 582-587. 

Daytime oxidation chemistry, 17 791-792 2,4-D [(2,4-Dichlorophenoxy)acetate] bioremediation substrate, 3 773, 774 herbicide/algicide for aquaculture in U.S., 3 215t... 

It is important to keep in mind that any extraction of organic matter from soil will include both naturally occurring organic matter and organic contaminants. Separating the two at some later stage of analysis is thus an essential analytical step. For example, extraction of soil with hexane or dichloromethane will extract both l,l,l-trichloro-2,2-di(4-dicholorphenyl)ethane (DDT), a contaminant, and octadecanoic acid, a natural fatty acid. Also, the herbicide 2,4-dichlorophenoxy acetic acid, a contaminant, and indole-3-acetic acid, a natural plant hormone, are both extracted by water (see Figure 12.3). These... 

Renberg [154] has described a method for the determination of 2.4 dichlorophenoxy acetic acid (2.4D) and 2.4.5 tri chlorophenoxy acetic acid (2.4.5T) in soils in which the herbicide is derivativized to its methyl or 2-chloroethyl ester prior to determination by gas chromatography. Recoveries of the two herbicides at the 8-16mg kgp1 level in soil were between 70-74% (2.4D) and 84-86% (2.4.5T). 

Lopez-Avila et al. [159] used isotope dilution gas chromatography-mass spectrometry to determine low levels of pg kgy1 2,4 dichlorophenoxy acetic acid herbicide in soil. 

Kavetskii et al. [224] developed a method for the simultaneous determination of pesticides in soil. A combination of thin layer chromatography and gas chromatography was used. The pesticides examined were 4,4 DDT, 4,4 DDD, 4,4 DDE, 2,4 DDT, GHCG, aGHCG, Metaphos, Phosphamidon, Phozalone, Atrazine, Prometryne, Simazine and 2,4 dichlorophenoxy acetic acid. Detection limits were in the range 0.5-5pg kgy1. 

Acid herbicides such as 2,4 dichlorophenoxy acetic acid, 2,4,5-trichlorophenoxy acetic acid, 3,6-dichloropicolinic acid and other types of herbicides such as Dicamba, Dichloroprop, Picloram, Fenoprop, 2,3,6-TBA, Bromoxynil and Ioxynil are widely used in agriculture and are often formulated as mixtures. They may also be mixed in the spray tank or used in sequence, so it is likely that residues of more than one of these compounds may be present in the soil. 

Lawns also represent an urban ecological problem on a vast scale. In the United States, the chemicals of lawn maintenance-including dichlorophenoxy-acetic acid (2,4-D), glyphosate, diazinon, and dicamba-are significant contributors to nonpoint source water quality problems that continue to elude solution almost 30 years after the passage of the Clean Water Act. Lavm pesticides are applied on a scale to rival agricultural toxins 23% of the total 2,4-D applied in the United States is used on lawns 22% of glyphosate, 31% of chlorpyrifos, and 38% of dicamba used nationally is applied to home lavms. ... 

Dichlorophenol, see 2,4-Dichlorophenol 3-(3,4-Dichlorophenol)-l,l-dimethylnrea, see Dinron Dichlorophenoxyacetic acid, see 2,4-D (2.4-Dichlorophenoxy)acetic acid, see 2,4-D 3-(3,4-Dichlorophenyl)-l,l-dimethylnrea, see Dinron A -(3,4-Dichlorophenyl)-lV,lV-dimethylnrea, see Dinron Dichlorophos, see Dichlorvos a.p-Dichloropropane, see 1,2-Dichloropropane ds-l,3-Dichloropropene, see cis-l,3-Dichloropropylene frans-l,3-Dichloropropene, see ans-l,3-Dichloro-... 

Dichlorophenol. see a-BHC. Pentachlorophenol (2.5-Dichlorophenoxy)acetic acid, see 2.4.5-T (2.6-Dichlorophenoxy)acetic acid, see 2.4-D... 

Faust, S.D. and Aly, O.M. Evaluationof the solubilitiesofthe calcium and magnesium saltsof2,4-dichlorophenoxy acetic acid,... 

Que Hee, S.S., Sutherland, R.G., McKinlay, K.S., and Sara, J.G. Factors affecting the volatility of DDT, dieldrin, and dimethylamine salt of (2,4-dichlorophenoxy)acetic acid (2,4-D) from leaf and glass surfaces. Bull Environ. Contam. Toxicol, 13(3) 284-290, 1975. 

Fenclofenac Fenclofenac, o-[2,4-dichlorophenoxy)phenyl]acetic acid (3.2.45), is synthesized from 2,4-dichlorophenol and 2-chloroacetophenone, the reaction of which in the presence of sodinm hydroxide and powdered copper forms the corresponding 2-acetyl-2, 4 -dichloro-diphenyl ester (3.2.43). The resulting product is reacted with sulfur and morpholine according to Willgerodt method, giving thioamide (3.2.44), which is further hydrolyzed to the desired fenclofenac [109,110]. 

Several amperometric immunosensors have been developed for monoclonal antibodies (IgG), a-interferon and the pesticide 2,4-dichlorophenoxy-acetic acid (2,4-D) by using a flow-cell with the catching antibody covalently bound to a cellulose acetate or activated nylon membrane as shown in Fig. 3.31. B. With multiepitope antigens (e.g. a protein), after the antigen is bound and washed, a second enzyme-labelled antibody is used to form a sandwich... 

With deeper understanding of the rate laws applicable to these hydrolases, now we need to deduce the parameters that combine to give corresponding khl0 values for Michaelis-Menten cases (Eq. 17-80). We may now see that the mathematical form we used earlier to describe the biodegradation of benzo[f]quinoline (Eq. 17-82) could apply in certain cases. Further we can rationalize the expressions used by others to model the hydrolysis of other pollutants when rates are normalized to cell numbers (e.g., Paris et al., 1981, for the butoxyethylester of 2,4-dichlorophenoxy acetic acid) or they are found to fall between zero and first order in substrate concentration (Wanner et al., 1989, for disulfoton and thiometon). 

Rearrangements have been observed in the case of aryloxyacetic acids a-substituted by an aryl group (96, R = H, R2 = Ph, X = OH), which give 3-phenyl-2(3//)-benzofuranone (98).278 2,4-Dichlorophenoxy-acetic acid and its chloride do not undergo ring closure by any method.279... 

Often overlooked is the possibility that derivatization also provides qualitative information. For example, assume the suspect compound is a herbicide such as 2,4-D (2,4-dichlorophenoxy acetic acid). As such, this compound cannot be reasonably chromatographed and detected at trace levels. Therefore, it is customarily converted to the corresponding methyl ester and analysis is based upon comparison to standards of the corresponding methyl ester. The qualitative information available from this sequence is ... 

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