Carbendazime

Microtubulin Polymerization Inhibitors. The ben2imida2oles were first reported to have systemic fungicidal activity in 1964 (29). Prominent examples include thiabendazole [148-79-8] (42) fuberida2ole [3878-19-1] (43) carbendazim [10605-21-7] (44) benomyl [17804-35-2] (45) and thiophanate methyl [23564-05-8] (46). Benomyl (45), the most widely used member of this group is almost certainly inactive as a fungicide until it is converted in plants and soil to carbendazim (44). Likewise, thiophanate and thiophanate methyl (46) are nonfungitoxic until converted to carbendazin (44). 

Phenylurea herbicides (urons). Dinocap, Dinoseb, Benomyl, Carbendazim and Metamitron in Waters [e.g. determination of phenylurea herbicides by reverse phase HPLC, phenylurea herbicides by dichloromethane extraction, determination by GC/NPD, phenylurea herbicides by thermospray LC-MS, Dinocap by HPLC, Dinoseb water by HPLC, Carbendazim and Benomyl (as Carbendazim) by HPLC], 1994... 

A method has been reported for the quantification of five fungicides (shown in Figure 5.39) used to control post-harvest decay in citrus fruits to ensure that unacceptable levels of these are not present in fruit entering the food chain [26]. A survey of the literature showed that previously [27] APCl and electrospray ionization (ESI) had been compared for the analysis of ten pesticides, including two of the five of interest, i.e. carbendazim and thiabendazole, and since it was found that APCl was more sensitive for some of these and had direct flow rate compatibility with the HPLC system being used, APCl was chosen as the basis for method development. 

A subsequent comparison of these ionization techniques for the study of another eight pesticides, this time including three of the five of interest [28], i.e. carbendazim, thiabendazole and thiophanate methyl, showed that ESI gave enough sensitivity to allow reliable determination of the pesticides at concentrations below their respective maximum residue levels. 

The method was then applied to extracts of orange peel but neither benomyl or thiophanate methyl were recovered as the parent compounds due to their well-known conversion to carbendazim during the extraction process - this is an effect that is not encountered when analysing standards. 

For an individual pesticide (e.g., carbendazim) or a limited class of pesticides (e.g., carbamates, benzoylphenylureas, pyrethroids ), it may be possible to optimize the SPE conditions so that the pesticide(s) are selectively retained on the cartridge. A wash step can be introduced to elute the matrix selectively, thus producing an extremely clean extract. For example, when cleaning up sample extracts for carbendazim analysis, a cation-exchange (SCX) cartridge may be used and the pH carefully controlled to retain the carbendazim firmly, whilst the co-extractives are washed to waste. The carbendazim residues can then be eluted from the column by adjusting the pH. 

If acid-sensitive analytes (e.g., myclobutanil, propiconazole, tebuconazole, fiuotri-mazole, thiabendazole, carbendazim) are extracted from an acidic material (e.g., citrus fruits, berries, several sorts of apples and tomatoes), only low recoveries are obtained. If the pH of an aqueous homogenate of the material is <5, use Module E3, where the acids are neutralized before the extraction. 

The extraction described above is highly recommended for determining acid-sensitive analytes (e.g., myclobutanil, propiconazole, tebuconazole, fluotrimazole, thiabendazole, carbendazim). 

The extraction Module E3 is particularly suitable for the analysis of the partly acid-sensitive azoles (e.g., myclobutanil, propiconazole, tebuconazole, fluotrimazole, thiabendazole, carbendazim). By combining the cleanup step using a GPC column and separation on a small silica gel column, 27 azoles, four benzimidazoles and thiazoles and live imidazolines could be determined with this multi-residue method. 

Marvin, C. H., Brindle, I. D., Singh, R. P., Hall, C. D., and Chiba, M., Simultaneous determination of trace concentrations of benomyl, carbendazim (MBC) and nine other pesticides in water using an automated on-line pre-concentration high-performance liquid chromatographic method, /. Chromatogr., 518, 242, 1990. 

Increase in the number of daughter chromatid changes, lengthening of the cell cycle Nitro-aldicarb, bavistin (carbendazim), malathion... 

The widely used insecticide carbaryl (FD50=270 mg/kg) transforms in oxidizing processes into 5-oxynaphthyl-N-methylcarbamate, a substance that is as toxic as carbaryl itself (FD50=297 mg/kg) [30, 33]. One of the metabolites of the fungicide benomyl, the methyl ester carbamino acid (BMK, carbendazim), is also toxic to fungi [33]. 

Fig-1 SPE-LC-ESI-MS analysis (SIM mode) of two wastewater samples, spiked at different levels of concentration. Compounds (1) ciromazine, (2) oxamil, (3) metomil, (4) carbendazime, (5) thiabendazole, (6) imidacloprid, (7) acetamiprid, (8) thiacloprid... 

The mutagenic aminophenazines 71 are present as impurities of carbendazim (72) fungicides and its formulations. They were determined by HPLC-UVD (diode array), using 0.02% sulfuric acid in MeOH, and measuring at 270 and 453 nm186. 

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