Apples thiabendazole

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. 

Further insight on the frequency of multiple residues is evident in Table 14.4, which shows the number of residues found per sample for selected foods tested in 2004 by the PDP. Conventional apples were found to contain, on average, 3.6 residues, while the one positive organic sample had a very minute level of the post-harvest fungicide thiabendazole. The level of residue found in the one positive organic apple sample was 0.0002 parts per million, while the mean thiabendazole residue found in 641 positive conventional samples was 0.43 ppm, over 2100 times higher than the level found in the organic sample. 

Another import field of development is the investigation of pesticides transformation products in food. Some examples are the investigation of the acaricide amitraz and its transformation products, 2,4-dimethylaniline (DMA), 2,4-dimethylformamidine (DMF), and N-2,4-dimethylphenyl-N-methylformamidine (DMPF) in pears [220] Antioxidant pesticides as well as their metabolites used in postharvest treatment have been investigated in pears and apples with concentrations in the ranges 0.002-0.672 ng/g (ethoxyquin), 0.94-11.86 ng/g (imazalil), 0.024-0.902 ng/g (diphenylamine), 0.012-2.59 ng/g (thiabendazole). 

Brandon [11] developed an enzyme immunoassay method using monoclonal antibodies to determine thiabendazole in apples and potatoes. 

Apples Diphenylamine (DPA), Thiabendazole, and Azinphos Methyl Vitamins A, C, Potassium Oranges, Bananas, Kiwis, Watermelon, Tangerines... 

Quantification. High Pressure Liquid Chromatography. In serum thiabendazole and 5-hydroxythiabendazole, detection limit 100 ng/ml and 400 ng/ml, respectively, fluorescence detection—M. T. Watts etaL, J. Chromat., 1982, 230, Biomed. AppL, 19, 79-86. 

All garden enthusiasts know about the nice autumn crocus (Colchicum autumnale), which flowers in late autumn. It is not difficult to understand that this very conspicuous plant profits by containing a strong poison that protects it from pathogens and herbivores. It contains colchicine, which is very toxic and has a complicated structure. The substance is well known to plant breeders because it is used to double the number of chromosomes artificially in plants. A synthetic benzimidazole derivative, l-methyl-3-dode-cylbenzimidazolium chloride, was developed in 1960 as a curative fungicide against apple scab. Thiabendazole, another synthetic benzimidazole derivative, has been used as an anthelmintic since 1962. 

Pesticide residues (dinoseb, pirimicarb, procymidone, pyrifenox, pyrimethanil, and thiabendazole) in peaches and nectarines Fungicide residues (procymidone and thiabendazole) in apples, grapes, oranges, pears, strawberries, and tomatoes Pesticides and metabolites (naphthalene acetamide, carbaryl, 1-naphthol, thiabendazole, and carbendazime) in cucumbers Amino phosphonic acid herbicides (model mixture)... 

Robinson, J. H., Stoertz, H. C. Graessel, O. E. (1965). Studies on the toxicologic and pharmacologic properties of thiabendazole. Toxicol Appl Pharmacol, 7, 53-63. 

Benzimidazoles. The best-known examples, which were introduced in 1967/8, are Benomyl and Thiabendazole. Both have been widely accepted as broad-spectrum systemic fungicides active against botrytis, powdery mildews, apple scab and as a seed dressing against common bunt of wheat. 

FIGURE 13.5 UHPLC—MS/MS separation of an apple extract, fortified with 17 polar pesticides. Peak identification (1) carbendazim, (2) thiabendazole, (3) carbofuran, (4) carbaryl, (5) linuron, (6) methiocarb, (7) epoxiconazole, (8) flusilazole, (9) diflubenzuron, (10) tebuconazole, (11) imazalil, (12) propiconazole, (13) trUlumuron, (14) bitertanol, (15) prochloraz, (16) teflubenzuron, (17) flufenoxuron. Source From Reference 181], reproduced by permission of Elsevier. 

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