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9. QUANTIFICATION OF IONOPHORE ANTIMICROBIALS ASSOCIATED WITH POULTRY LITTER AND THEIR DYNAMICS IN THE SOILS OF THE MID-ATLANTIC USA

Author

Biswas, Saptashati and Biswas, Saptashati

Abstract

Anticoccidants, biochemically known as ionophores are added to poultry feed for growth promotion, prophylactic and therapeutic purposes to better sorb nutrients and against coccidiosis caused by parasite Eimeria sp. Ionophores belong to the class of emerging contaminants, as they are not regularly monitored in the environment and not specifically treated in the effluents. Potentially, this can cause ionophores to enter into the environment freely. There is little information regarding the dynamics of ionophores in the environment. This has been related to the lack of reliable, sensitive and robust methods that can measure their trace levels from complex environmental matrices like soil, natural water and animal manure. Studies show ionophore toxicity exhibited in flora and fauna, even reported in humans above the dose of 1 mg kg-1. Hence accumulation of ionophores in the environmental can be detrimental. Our multi-scale investigation of ionophores involved, a) method development for trace analysis of ionophores in poultry manure using liquid chromatography triple quadrupole mass spectrometry (HPLC-–MS/MS), b) batch equilibrium studies of ionophores using soils from mid-Atlantic region of the USA and c) influence of soil physico-chemical parameters on dynamics of ionophores in soil-water systems. Our HPLC-–MS/MS method was successful in quantifying ionophores ranging from (19.19 ±± 6.6) µg kg-1 to (97.86 ±± 19.19) µg kg-1 with concentrations of monensin being the highest. This method was further used to investigate partitioning of monensin in soil-ndash;water systems relevant to the occurrence of ionophores in the natural environment. Sorption and desorption isotherms were developed and influence of soil physico-chemical parameters on the sorption-desorption processes were analyzed. C-–type linear isotherms were generated with partition coefficients ranging from (6.41±&plusm

Published
2014

12. SulfateBridged Dimeric CopperII Complexes with ThreeDimensional Network: Synthesis, Structure and DFT Studies

Author

Basu, Chandrama, Biswas, Saptashati, Chattopadhyay, Asoke P., StoeckliEvans, Helen, and Mukherjee, Soma

Abstract

The 1:1 reaction of the diacetyl monoxime2pyridyl hydrazone HL11 and the pyridine2carboxaldehyde2imidazoline hydrazone hydrobromide HL22 with copperII sulfate pentahydrate in methanol affords a series of new sulfatebridged dimeric copperII complexes, [CuII2HL12μSO42]·4H2O 1a and [CuII2HL22μSO4Br2]·2H2O 2a, respectively. The room temperature magnetic moments of the complexes 1aand 2aare 1.82 μβand 1.84 μβ, respectively. The bands appearing in the UV region 200–340 nm are characteristic of the ligands HL11 and HL22. In complexes 1aand 2a, these ligand centred bands are accompanied by multiple bands extending into the visible region 370–480 nm. The association constant Kass, UVVis was found to be 1.120 ± 0.002 × 105for 1aand 1.196 ± 0.002 × 104for 2aat 298 K determined using UVVis spectroscopy. On excitation at 285 nm, ligand 1emits strongly in the 364 nm region due to an intraligand 1π–π transition. Upon complexation with copperII, the emission peak is slightly blue shifted 354 nm, FFo0.89 with a little quenching in the emission intensity as expected for divalent copper. Complexes 1aand 2aexhibit two consecutive oxidation couples for two copperII centres in deionised distilled water under a nitrogen atmosphere. DFT and TDDFT calculations were performed and the results are highly consistent with the spectroscopic behaviour of the complexes. The molecular structures of dinuclear 1aCu···Cu 4.555 Å and 2aCu···Cu 6.106 Å have been determined by singlecrystal Xray diffraction studies.© WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008

Published
2008
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