Preparation, Characterization, and Biological Activity of Amides and Esters from 8-Hydroxyquinoline-2-Carboxylic Acid and Jeffamines ED® Or Poly(Ethylene Glycol)S

New macromolecular chelators were synthesized under mild conditions by reaction of 8-hydroxyquinoline-2-carboxylic acid (8Q2COOH) with polyethers having amino end-groups (Jeffamines ED®) or poly(ethylene glycol)s in the presence of dicyclohexylcarbodiimide and dimethylamino-pyridine. The prepared amides (8Q2CONH-POE) and esters (8Q2COO-POE) were characterized by SEC, DSC, IR, 1H and 13C NMR spectroscopy, and MALDI-TOF mass spectrometry. It was found that the polyethers had 8-hydroxy-2-quinolinyl end groups and formed complexes with Fe3+ ions. The obtained complexes were studied with IR spectroscopy and DSC. The plant tests showed that the Fe3+ complex of 8Q2CONH-POE2000 had high efficacy in the remedy of iron-deficient maize plants under hydroponic conditions.

Effect of grain storage and processing on chlorpyrifos-methyl and pirimiphos-methyl residues in post-harvest-treated wheat with regard to baby food safety requirements

A study was undertaken to assess the effects of storage intervals and of milling procedures on the dissipation of chlorpyrifos-methyl and pirimiphos-methyl residues in post-harvest-treated wheat grain and to obtain scientific data on the compliance of the processed products with safety requirements concerning baby foods. The insecticide formulations were applied on stored wheat at recommended rates (20 ml t(-1)). The initial concentration levels in whole grain were determined in samples taken 1 h after treatment. The dissipation of residues and their distribution in different fractions of the milled grain were studied after various storage intervals, from 7 to 270 days after treatment. Samples of treated grain were milled in a fractionating laboratory mill and eight fractions--bran, semolina, three types of groats and three types of flour--were collected and analysed for pesticide residues. The residues were determined by an analytical method based on acetone extraction, graphitized carbon clean-up and GC-ECD, respectively, and GC-NPD determination of residues. The limits of determination of both pesticides were 0.005 mg kg(-1), which is high enough for enforcement of the European Commission Directive that established a maximum residue level of 0.01 mg kg(-1) for any pesticide in cereal-based baby food. The results showed that the pesticides chlorpyrifos-methyl and pirimiphos-methyl applied post-harvest on wheat as grain protectants were distinguished by relatively low rates of degradation in the grain under practical storage conditions. Milling did not significantly reduce the bulk of the chemicals but resulted in the distribution of residues in various processed products. The main part of the insecticides deposited on the grain remained in the bran and partly in semolina fractions. After 270 days of treatment, the residues of chlorpyrifos-methyl were within the range 0.8-2.1 mg kg(-1) and of pirimiphos-methyl - between 0.6 and 3.7 mg kg(-1) in the various types of flour.