Spectrophotometric Determination of Lead by Extraction of the Mixed-Metal Complex Pb(II)-Ca-Purpurin (1,2,4-Trihydroxyanthraquinone)

Ramírez, Adriana Citlali; Gázquez, Domingo; Rosa, Igor M. De; Moreno, Francisco Jiménez

doi:10.1080/00032719408006392

Cited by 8 publications

(4 citation statements)

References 5 publications

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“…It is rapid compared with the previously reported procedures for the separation and determination of lead; [8][9][10][11] the time taken for the separation and analysis of lead in a 500-cm 3 water sample is at most 35 min. The LOD of the method (75 ng per 1000 cm 3 ) is improved by a factor of 67, as it compared with that of the previously reported SPE procedure.…”

Section: Resultsmentioning

confidence: 96%

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Separation and Preconcentration of Trace Amounts of Lead on Octadecyl Silica Membrane Disks Modified with a New O, S-Containing Schiff’s Base and Its Determination by Flame Atomic Absorption Spectrometry

et al. 2000

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Section: Resultsmentioning

confidence: 96%

“…The liquid-liquid extraction and separation of lead ion in the presence of classical [8][9][10] and macrocyclic ligands [11][12][13][14] is frequently reported in the literature. However, classical extraction methods are usually time consuming and labor intensive and require relatively large volumes of high-purity solvents.…”

mentioning

confidence: 99%

Separation and Preconcentration of Trace Amounts of Lead on Octadecyl Silica Membrane Disks Modified with a New O, S-Containing Schiff’s Base and Its Determination by Flame Atomic Absorption Spectrometry

et al. 2000

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“…For the interference assays, lead calibrating solutions with different concentrations of the interferent were prepared from stock solutions of 1 g/l previously attained by weighing and diluting the following substances: Li 2 …”

Section: Reagents and Solutionsmentioning

confidence: 99%

“…Therefore, a preconcentration procedure is required both for minimizing the matrix interferences and improving the detection limit. The preconcentration of heavy metals in natural water has been performed by means of evaporation, solvent extraction 2,3 , ion-exchange and chelating resins [4][5][6][7] as well as coprecipitation. 8 When automating these procedures in continuous-flow units, faster determinations and a better quality of results are attained.…”

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confidence: 99%

Application of Sequential Injection Analysis to the Assay of Lead Retention Characteristics by Poly(vinylpyrrolidone): Trace Analysis of Lead in Waters

1999

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Because heavy metals are usually present in water at trace levels, their determination can only be performed by highly sensitive analytical methodologies, namely electrothermal atomic absorption spectrophotometry (ETAAS) 1 , which is the most widely used. This technique is very expensive, though, as far as its purchase and daily use are concerned. Flame atomic absorption spectrophotometry (FAAS) is much cheaper and less complex in terms of handling, but its sensitivity is too low for this type of determination. Therefore, a preconcentration procedure is required both for minimizing the matrix interferences and improving the detection limit. The preconcentration of heavy metals in natural water has been performed by means of evaporation, solvent extraction 2,3 , ion-exchange and chelating resins 4-7 as well as coprecipitation. 8 When automating these procedures in continuous-flow units, faster determinations and a better quality of results are attained.Automatization by preconcentration in a homogeneous medium, called liquid-phase polymer-based retention (LPR) [9][10][11][12] , is also proposed. It consists of using soluble polymers, such as poly (vinylpyrrolidone), that perform selective complexation of the ion that is being concentrated according to the solution pH. The addition of a soluble polymer to the sample enables a more effective retention of the species intended by means of sample ultrafiltration. Although this automatization procedure is much more expensive than continuous-flow techniques, the polymers used are rather cheap when compared to the resins similarly employed in continuous flows.The present work reports on the behavior of poly-(vinylpyrrolidone) when used for the preconcentration of lead in the heterogeneous stage and continuous-flow conditions. Hence, the coupling of an analytical unit to a simple sequential injection analysis system has been studied and is being proposed. It is common knowledge that sequential injection analysis is a third-generation flow technique 13 characterized by being more robust and versatile regarding the variation of the analytical conditions. Therefore, a preconcentration procedure based on easily implemented analytical columns may be very advantageous, because the feeble optimization of the columns can be overcome by the hydrodynamic conditions featured by the SIA systems. Experimental Reagents and solutionsAll solutions were prepared with bideionized water (conductivity <0.1 µS/cm) and analytical-grade reagents without any further treatments.Lead calibrating solutions were prepared by dilution with water from a stock solution of 1 g/l lead previously prepared with Pb(NO 3 ) 2 . The pH of the calibrating solutions was set to the average level attained from the samples (pH=3) by adding 2 mol/l HNO 3 .For the interference assays, lead calibrating solutions with different concentrations of the interferent were prepared from stock solutions of 1 g/l previously attained by weighing and diluting the following substances: Faculdade de Farmácia (U.P.), Rua Anibal ...

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Solid Phase Extraction and Determination of Trace Amounts of Lead(II) Using Octadecyl Membrane Disks Modified by a New Schiff's Base and Flame Atomic Absorption Spectrometry

Mohammadhosseini

Tehrani

2006

J Chinese Chemical Soc

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A highly selective, facile and reliable method for separation and preconcentration of the trace amounts of lead present in aqueous samples is introduced. By passing the solutions through an octadecyl silica membrane disk modified by a novel Schiff's base, Pb 2+ ions are adsorbed quantitatively while almost all interfering ions pass through the disk. The retained lead(II) ions are then eluted from the disk surface by a minimal amount of organic eluents. The influences of pH, sample flow-rates and interfering ions are also investigated. The proposed method permits an enrichment factor of about 500 or higher and a detection limit of 0.0065 ng mL -1 .

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Spectrophotometric Determination of Lead by Extraction of the Mixed-Metal Complex Pb(II)-Ca-Purpurin (1,2,4-Trihydroxyanthraquinone)

Cited by 8 publications

References 5 publications

Separation and Preconcentration of Trace Amounts of Lead on Octadecyl Silica Membrane Disks Modified with a New O, S-Containing Schiff’s Base and Its Determination by Flame Atomic Absorption Spectrometry

Separation and Preconcentration of Trace Amounts of Lead on Octadecyl Silica Membrane Disks Modified with a New O, S-Containing Schiff’s Base and Its Determination by Flame Atomic Absorption Spectrometry

Application of Sequential Injection Analysis to the Assay of Lead Retention Characteristics by Poly(vinylpyrrolidone): Trace Analysis of Lead in Waters

Solid Phase Extraction and Determination of Trace Amounts of Lead(II) Using Octadecyl Membrane Disks Modified by a New Schiff's Base and Flame Atomic Absorption Spectrometry

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