Metazachlor

Chloroacetanilides are soil-applied herbicides used for pre- and early post-emergence control of annual grasses and broadleaf weeds in crops. Representative chloroacetanilide compounds, alachlor, acetochlor, and metolachlor, are extensively used worldwide. Other chloroacetanilides with limited usages include propachlor, bu-tachlor, metazachlor, pretilachlor, and thenylchlor. Public environmental concerns and government regulatory requirements continue to prompt the need for reliable methods to determine residues of these herbicides. There now exist a variety of analytical methods to determine residues of these compounds in crops, animal products, soil, and water. The chemical structures and major crops in which these compounds are used are summarized in Table 1. 

Me Me Metazachlor 67129-08-2 Potato, oilseed rape, soybeans, vegetables... 

Solid-phase microextraction (SPME) is also a useful alternative to conventional sample cleanup with LLE or SPE. SPME is based on the enrichment of analytes by a partitioning process between a polymeric phase coated on a fused-silica fiber and its surrounding aqueous solution. SPME combines sample preparation in terms of extraction from a matrix of interfering compounds with an enrichment process in a single step. A method for the determination of metazachlor in wastewater samples is described in the literature [34]. In this study, SPME was shown to be a suitable and simple sample preparation method for the determination of metazachlor in wastewater by GC-AED. 

Hessler, D.P., V. Gorenflo, and F.H. Frimmel (1993). Degradation of aqueous atrazine and metazachlor solutions by UV and UV/H202 -Influence of pFl and herbicide concentration. Acta Hydrochim. Hydrobiol., 21 209-214. 

Merphos phosphoro organic, phosphoro tri thioite Metalaxyl amide Metam dithiocarbamate Metamitron heterocyclic nitrogen, triazine Metazachlor amide, pyrazole Metconazole heterocyclic nitrogen, triazole Methabenzthiazuron urea, benzothiazole Methacrifos phosphoro organic, phosphoro thioate Metham-sodium see Metam... 

Dimethyl aniline benalaxyl, dimethachlor, fiiralaxyl, metalaxyl, metazachlor, ofurace, thenylchlor 2.3. Dimethyl benzoic acid imazamethabenz... 

Propyn-1 ol see Propargylic alcohol Pseudo urea (methyl thio) hexazinone Pyrazole metazachlor... 

Chloracetanilide herbicides like alachlor, metolachlor and metazachlor can be analysed in positive-ion mode. In ESI, protonated and sodiated molecules are observed as well as the loss of methanol [16, 34, 47, 63]. The MS-MS spectmm of alachlor was stndied, nsing MS-MS and in-source CID on a orthogonal-acceleration time-of-flight mass spectrometer [63]. 

Metazachlor (21) is a halogenated acetanilide developed by the BASF, with the chemical name 2-chloro-2,6-dimethyl-N-(lH-pyrazol-l-yl-methyl)acetanilide (Stormonth and Woodroffe, 1982). 

Metazachlor is a selective preemergence herbicide active on a wide range of both broad-leaved and grass weeds. It can be used selectively in Brassica spp. crops including winter oilseed rape at a rate of 1-1.8 kg active ingredient/ha. 

Butisan . [BASF AG] Metazachlor systemic herbicide controlling annual grasses, broadleaf weeds. 

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