Suneeti Singh - Academia.edu (original) (raw)
I am results oriented, constantly checking in with the goal to determine how close or how far away we are and what it will take to make it happen. I find this pressure inspiring and a great motivator for the rest of the team.
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A simple, sensitive and inexpensive flow injection solid phase extraction (SPE) system is develop... more A simple, sensitive and inexpensive flow injection solid phase extraction (SPE) system is developed for automatic determination of trace level concentrations of Cd(II). The potentials of this novel scheme, coupled to flame atomic absorption spectroscopy (FAAS) is demonstrated for trace Cd(II) in natural water samples.The Xylenol Orange immobilized on Amberlite XAD-16 has been synthesized and is used for on-line preconcentration of Cd(II) with a flow injection–flame atomic absorption spectroscopy (FI–FAAS). All main chemical and hydrodynamic parameters affecting the complex formation, sorption and elution of the analyte were optimized thoroughly. The results demonstrated that Cd(II)can be determined using sample pH of 4.5 – 5.0, elution with 0.5 mol L −1 nitric acid and a sample flow rate of 5.0 mL min -1 . Moreover, the effect of potential interfering species occurring in natural water samples were also explored. Enrichment factor of 171 was achieved by using the time-based techniqu...
A rapid and sensitive method for the determination of trace level of Cd(II) in industrial effluen... more A rapid and sensitive method for the determination of trace level of Cd(II) in industrial effluents by flame atomic absorption spectroscopy has been developed. The technique is based on the online flow injection preconcentration of Cd(II) ions on a mini column, packed with Amberlite XAD-2 functionalized with xylenol orange. Flow injection variables have been optimized for the determination and quantitative preconcentration of Cd(II). Cd(II) ions are effectively retained on the mini column at pH 5.0. A high sorption capacity of 348 μmol/g of dry resin is obtained and chelating resin can be reused for 70-80 cycles of sorption desorption without any significant change in the sorption capacity. With preconcentration times of 60 s and 120 s at a sample loading flow rate of 5 mL min, preconcentration factors of 17 and 32 are obtained. The calibration graph using the preconcentration system for Cd(II) is linear over the concentration range of 0-120 μg L. The precision for 5 replicate measu...
An on-line system for preconcentration and determination of Pb(II) by FAAS at µg L -1 level is pr... more An on-line system for preconcentration and determination of Pb(II) by FAAS at µg L -1 level is proposed. A mini column is packed with Amberlite XAD-16 functionalized with Xylenol Orange via azo coupling and the resulting resin is explored for enrichment of Pb(II) at pH range 4 – 5. All chemical and flow injection variable were optimized for the quantitative preconcentration and determination of Pb(II). The calibration graph obtained was linear over the concentration range of 11.3 – 350 µg L -1 . The limit of detection and preconcentration factor at 180s loading time were 1.9 µg L -1 and 65 respectively. The precision (relative standard deviation) at 200 µg L -1 Pb(II) concentration level was 3.9%. A sample frequency of 30 h -1 was obtained for 60s preconcentration time of sample solution at flow rate of 5mLmin -1 . The accuracy of the proposed preconcentration procedure was validated by performing the spiked recovery studies in water sample using certified Pb(II) nitrate solution tr...
A simple, sensitive and inexpensive flow injection solid phase extraction (SPE) system is develop... more A simple, sensitive and inexpensive flow injection solid phase extraction (SPE) system is developed for automatic determination of trace level concentrations of Cd(II). The potentials of this novel scheme, coupled to flame atomic absorption spectroscopy (FAAS) is demonstrated for trace Cd(II) in natural water samples.The Xylenol Orange immobilized on Amberlite XAD-16 has been synthesized and is used for on-line preconcentration of Cd(II) with a flow injection–flame atomic absorption spectroscopy (FI–FAAS). All main chemical and hydrodynamic parameters affecting the complex formation, sorption and elution of the analyte were optimized thoroughly. The results demonstrated that Cd(II)can be determined using sample pH of 4.5 – 5.0, elution with 0.5 mol L −1 nitric acid and a sample flow rate of 5.0 mL min -1 . Moreover, the effect of potential interfering species occurring in natural water samples were also explored. Enrichment factor of 171 was achieved by using the time-based techniqu...
A rapid and sensitive method for the determination of trace level of Cd(II) in industrial effluen... more A rapid and sensitive method for the determination of trace level of Cd(II) in industrial effluents by flame atomic absorption spectroscopy has been developed. The technique is based on the online flow injection preconcentration of Cd(II) ions on a mini column, packed with Amberlite XAD-2 functionalized with xylenol orange. Flow injection variables have been optimized for the determination and quantitative preconcentration of Cd(II). Cd(II) ions are effectively retained on the mini column at pH 5.0. A high sorption capacity of 348 μmol/g of dry resin is obtained and chelating resin can be reused for 70-80 cycles of sorption desorption without any significant change in the sorption capacity. With preconcentration times of 60 s and 120 s at a sample loading flow rate of 5 mL min, preconcentration factors of 17 and 32 are obtained. The calibration graph using the preconcentration system for Cd(II) is linear over the concentration range of 0-120 μg L. The precision for 5 replicate measu...
An on-line system for preconcentration and determination of Pb(II) by FAAS at µg L -1 level is pr... more An on-line system for preconcentration and determination of Pb(II) by FAAS at µg L -1 level is proposed. A mini column is packed with Amberlite XAD-16 functionalized with Xylenol Orange via azo coupling and the resulting resin is explored for enrichment of Pb(II) at pH range 4 – 5. All chemical and flow injection variable were optimized for the quantitative preconcentration and determination of Pb(II). The calibration graph obtained was linear over the concentration range of 11.3 – 350 µg L -1 . The limit of detection and preconcentration factor at 180s loading time were 1.9 µg L -1 and 65 respectively. The precision (relative standard deviation) at 200 µg L -1 Pb(II) concentration level was 3.9%. A sample frequency of 30 h -1 was obtained for 60s preconcentration time of sample solution at flow rate of 5mLmin -1 . The accuracy of the proposed preconcentration procedure was validated by performing the spiked recovery studies in water sample using certified Pb(II) nitrate solution tr...