Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical car...Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.展开更多
In last few decades there is exponential increase in use of organophosphorus (OP) compounds as pesticides and insecticides leading to adverse effect on human population and live stock. There is a great need to develop...In last few decades there is exponential increase in use of organophosphorus (OP) compounds as pesticides and insecticides leading to adverse effect on human population and live stock. There is a great need to develop portable analytical tools that are amenable for remediation and bioremediation process monitoring, where rapid analysis of large number of samples is essential. Determination of various organophosphorus compounds has been achieved by integrating biocomponents with different transducers. The close integration of the biological events with the generation of a signal offers the potential for fabricating compact and easy-to-use analytical tools of high sensitivity and specificity. With the availability of new materials, associated with new sensing techniques has led to remarkable innovations in the design and construction of organophosphorus biosensors. The present review describes the specifications of most of the electrochemical Organophosphorus biosensors reported till date.展开更多
The title compound N,N,N’,N’-tetra[(diphenylphosphine)methyl]-1,4-phenylenediamine is synthesized by reaction of [Ph2P(CH2OH)2]Cl and 1,4-phenylenediamine.It is characterized by elemental analysis,IR,31PNMR,1HNMR.Si...The title compound N,N,N’,N’-tetra[(diphenylphosphine)methyl]-1,4-phenylenediamine is synthesized by reaction of [Ph2P(CH2OH)2]Cl and 1,4-phenylenediamine.It is characterized by elemental analysis,IR,31PNMR,1HNMR.Single crystal X-ray diffraction analysis reveals that it is centro-symmetric with the inversion center at the centroid of phenylene.Intermolecular π–π stacking interactions between phenyl rings make molecules arrange along the b axis into one-dimensional chains,while these chains are further extended by intermolecular C-H…π interactions into three-dimensional supramolecular structure.The crystal is orthorhombic system with space group Pbca,Mr: 900.90,a=12.215(1),b=14.460(2),c=27.821(3),β=90°,v=4914.0(9)3,z=4,Dc=1.218 mg·m-3,F(000)=1896,R=0.0487,wR=0.1245.展开更多
文摘Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.
文摘In last few decades there is exponential increase in use of organophosphorus (OP) compounds as pesticides and insecticides leading to adverse effect on human population and live stock. There is a great need to develop portable analytical tools that are amenable for remediation and bioremediation process monitoring, where rapid analysis of large number of samples is essential. Determination of various organophosphorus compounds has been achieved by integrating biocomponents with different transducers. The close integration of the biological events with the generation of a signal offers the potential for fabricating compact and easy-to-use analytical tools of high sensitivity and specificity. With the availability of new materials, associated with new sensing techniques has led to remarkable innovations in the design and construction of organophosphorus biosensors. The present review describes the specifications of most of the electrochemical Organophosphorus biosensors reported till date.
文摘The title compound N,N,N’,N’-tetra[(diphenylphosphine)methyl]-1,4-phenylenediamine is synthesized by reaction of [Ph2P(CH2OH)2]Cl and 1,4-phenylenediamine.It is characterized by elemental analysis,IR,31PNMR,1HNMR.Single crystal X-ray diffraction analysis reveals that it is centro-symmetric with the inversion center at the centroid of phenylene.Intermolecular π–π stacking interactions between phenyl rings make molecules arrange along the b axis into one-dimensional chains,while these chains are further extended by intermolecular C-H…π interactions into three-dimensional supramolecular structure.The crystal is orthorhombic system with space group Pbca,Mr: 900.90,a=12.215(1),b=14.460(2),c=27.821(3),β=90°,v=4914.0(9)3,z=4,Dc=1.218 mg·m-3,F(000)=1896,R=0.0487,wR=0.1245.
