Shiri, Fatemeh (2015) Solid-phase extraction followed by dispersive liquid-liquid microextraction for the determination of Lead and Cadmium in aqueous samples by graphite furnace atomic absorption spectrometry. Masters thesis, University of Zabol.
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Solid-phase extraction followed by dispersive liquid-liquid microextraction for the determination of Lead and Cadmium.pdf Download (141kB) | Preview |
Abstract
A solid-phase extraction coupled with dispersive liquid–liquid micro-extraction (DLLME) method followed by graphite furnace atomic absorption spectrometry (GFAAS) was developed for the extraction, pre-concentration, and determination of ultra-trace amounts of Lead, Cadmium and Nickle in real samples. In this work, SBA-15 mesoporous silica has been chemically synthesis and functionalized with metformin hydrochloride. The resulting material has been characterized and employed as solid phase extractant for pre-concentration of Pb+2, Cd+2 and Ni+2 ions. Variables affecting the performance of both steps were thoroughly investigated. Under optimized conditions, 100 mL of Pb+2, Cd+2 and Ni+2 solution were first concentrated using a solid phase sorbent SBA-15-Met. After extraction, the extracted ions by SBA-15- Met were stripped using 5 mL of 0.5 mol L-1 solution of nitric acid, then adjust the PH solution Nickle, Lead and Cadmium ions was concentrated by DLLME. In the DLLME procedure, metal ions Pb+2, Cd+2 and Ni+2 formed metal–dithizone complex and migrated into the carbon tetrachloride micro-droplets. The analytical figures of merit of method developed were determined. Under the optimized conditions, the limits of detection were 0.002 µg L-1 for Ni and 0.001 µg L-1 for Cd and Pb, with the enrichment factor of 1650. The precisions of this method (Relative standard deviation, RSD, n=3) for Pb+2, Cd+2 and Ni+2 at 1 µg L-1 were 4.9%, 5.2% and 5.0%, respectively. The proposed method was successfully applied for simultaneous pre-concentration of Pb2+, Cd2+ and Ni+2 ions in water and food sample.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Heavy Metal, Graphite furnace atomic absorption, Dispersive liquid-liquid micro-extraction, Solid-phase extraction |
| Subjects: | Q Science > QD Chemistry |
| Depositing User: | admin admin1 admin2 |
| Date Deposited: | 13 Nov 2016 04:50 |
| Last Modified: | 13 Nov 2016 04:50 |
| URI: | http://eprints.uoz.ac.ir/id/eprint/1005 |
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