Hexavalent chromium recovery by liquid–liquid extraction with 2-octylaminopyridine from acidic chloride media and its sequential separation from other heavy toxic metal ions

A systematic study of extraction of chromium(VI) with 2-octylaminopyridine (2-OAP) in xylene at room temperature has been conducted. Quantitative extraction of chromium(VI) was observed in the 0.4–0.8 M concentration range of hydrochloric acid. From the extracted complex species in the organic phase, chromium(VI) was back extracted with 7 N ammonia (3 × 10 mL), and was determined by spectrophotometric method. Various parameters such as 2-OAP concentration, equilibrium period, effect of various diluents, aqueous: organic volume ratio, acidity and diverse ions were studied. The extraction reaction proceeds with ion-pair formation and the stoichiometry of extracted species was found to be [(2OAPH+) CrO3Cl−](org). The separation and determination of chromium(VI) from associated and toxic metals in binary, ternary and multicomponent mixture were carried out. The method permits the sequential separation of chromium(VI) from other toxic metals and has been used to separate and determine chromium(VI) from alloys, and effluent water samples from tannery industries

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Not AvailableFood safety aspects of buprofezin, dimethoate and imidacloprid residues in pomegranate are reported. The residue analysis involved extraction of samples (15 g) with 10 ml ethyl acetate, cleanup by dispersive solid phase extraction with 25 mg primary secondary amine and 25 mg C18 sorbents and estimation by LC–MS/MS. The limit of quantification of each analyte was 0.001 mg kg−1 with recoveries within 76–109%. The residues of buprofezin and dimethoate were confined to outer rind, which degraded to below the maximum residue limit for the European Union (EU-MRL) after 10.5 and 31.5 days at standard dose and 32.0 and 44.0 days at double dose. Residues of imidacloprid penetrated into the albedo and membrane, although at less than the MRL in all samples even at double dose. The dietary exposure of buprofezin and imidacloprid was safe on all sampling days; whereas samples with dimethoate appeared safe after 15 and 30 days of field applications at standard and double doses, respectively.Not Availabl