Selective Separation and Preconcentration of Total Tin Using Quercetin as Chelating Agent

Abstract

Three methods were developed for rapid and selective extraction of total tin as Sn(IV) using quercetin (H5Q) as chelating agent, prior to its determination by hydride generation atomic absorption spectrometry (HGAAS). H5Q was chemically or physically immobilized onto silica gel or polyurethane foam, respectively, and used for the separation of Sn(IV) by the solid phase extraction (SPE) technique. The SPE methods were compared with flotation technique using the oleic acid as surfactant from H5Q solution in amyl alcohol/kerosene solvent. Elemental analysis, thermogravimetry, spectroscopic measurements (IR, UV/vis and magic angle solid state C 13 -NMR) were used to characterize the resulting modified extractors. The experimental conditions for efficient extraction of Sn(IV) such as: pH, time of stirring, interfering ions and eluent concentration, were optimized for the batchwise separation process. The tolerance limits of heavy metal ions in the sorption of Sn(IV) were reported. The methods were applied for the determination of total tin in water samples, zinc shots and canned beans after digestive oxidation. The suggested SPE and flotation techniques were found to be accurate and not subject to random error with especial preference to the SPE technique as it is cheaper and simpler.

Atomic Spectrometry Update. Clinical and biological materials, foods and beverages

“…210 A selective separation and preconcentration of Sn IV in water samples, as well as canned beans (and zinc shot), was accomplished after optimisation in a batchwise solid phase extraction (SPE) set-up using the polyphenolic compound quercetin, immobilised on silica gel or polyurethane foam, as chelating agent prior to HG-AAS. 211 A dispersive liquid-liquid microextraction preconcentration technique for the determination of total Pb by ETAAS in biological and water samples, using PMBP as chelating agent and CCl 4 and EtOH as dispersants, allowed a 78-fold concentration factor and LOD of 39 ng L À1 (defined as 3 Â SD). 56 A method for trace Mo determination in drinking water was developed using on-line FI-SPE-ICP-AES with ultrasonic nebulization.…”

Stabilization of Silica Gel against Hydrolysis by Doping with Fˉ or Zr(IV)

“…Silica Gel (SG), is one of the most important amorphous forms of silica that can be synthesized with surface areas up to 1300 m 2 •g −1 , while maintaining good mechanical stability. These characteristics best meet the requirements of ideal support for many heterogeneous advanced applications such as artificial bone implantaion [3,4], catalysis [5][6][7], sensors [8][9][10], fuel cells [11][12][13], and solid phase extraction [14][15][16][17][18][19][20][21][22].…”

Preconcentration of Sn in Real Water Samples by Solid Phase Extraction Based on the Use of Helvella leucopus as a Fungal Biomass Prior to its Determination by ICP-OES

“…The direct determination of Sn by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) is limited due to the poor sensitivity of these techniques and a preconcentration procedure is generally required before instrumental detection. Cloud point extraction (CPE) (4,5), solid phase extraction (SPE) (1,(6)(7)(8), coprecipitation (3), and liquid-liquid extraction (9) allow the detection of tin. However, they require the use of chemical ligands and time-consuming steps such as centrifugation.…”

“…In addition, synthesis procedures for ligands are eliminated when biomass is used as the sorbent. However, methods for the preconcentration of Sn were focused on the sorption of batch conditions (13), SPE on ligands (6)(7)(8), CPE (2,4,5,14), coprecipitation (3), and solvent extraction (9). Reports on the use of preconcentration methods for Sn using biomass are still very few.…”