An analytical method has been developed for the preconcentration of rare earth elements (REEs) in seawater for their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). An indigenously synthesized chelating resin was used for the preconcentration of (REEs) which was based on immobilization of fluorinated b-diketone group on solid support styrene divinyl benzene. Sample solutions (adjusted to optimized pH) were passed through a polyethylene column packed with 250 mg of the resin. Experimental conditions consisting of pH, sample flow rate, sample volume and eluent concentration were optimized. The established method has been applied for the preconcentration of light, medium and heavy REEs in coastal sea water samples for their subsequent determination by (ICP-OES). Percentage recoveries of La, Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb and Lu were ³ 95%, a preconcentration factor of 200 times, and relative standard deviations < 5% were achieved.

No abstract

Macroporus ethylacrylate‐divinylbenzene copolymers were synthesized by suspension polymerization using diethyl phthalate and n‐heptane as diluent. A hydrolysis study revealed that conversion of esters into carboxylic acid groups was dependent on three factors: (1) crosslinkage: increases with a decrease in crosslinkage, (2) reagent: sulfuric acid>aqueous NaOH>NaOH in a 1 : 1 water to ethylene glycol, and (3) pore volume (PV): highest when PV was ∼ 0.7 mL g−1. Sulfuric acid hydrolyzed ester to COOH and introduced SO3H on phenyl rings, thus producing a bi‐functional resin. The functional groups were verified by IR spectroscopy and quantified by acid–base titration. The bi‐functional resin's capacity for toxic heavy metals in water samples was 12.51, 10.43, 9.43, 13.21, and 11.12 mg g−1 for Cu, Cd, Ni, Pb, and Zn, respectively and the recoveries exceeded >95% in range of pH 2–8, showing that it is suitable for water purification. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

& A bi-functional sorbent derived from ethylacrylate-divinylbenzene copolymer was synthesized in beaded form by a suspension polymerization technique. Unlike conventional alkaline hydrolysis of the copolymer, a novel hydrolysis technique was used in this study and the copolymer was treated with concentrated sulfuric acid. More than 70% of the ester groups were converted into -COOH groups and about 60% of the aromatic rings in the copolymer were introduced by -SO 3 H groups. The synthesized copolymer was used as a solid-phase material for extraction of pesticides from water samples. Recoveries of five pesticides, namely, chlorfenvinfos, endosulfan sulfate, chlorpyrifos, fenvalerate, and diuron, were compared to those using commercially available silica-based C-18 sorbent. The recoveries obtained with the synthesized sorbent were low compared to commercial C18 cartridge. However, the synthesized polymer is cost effective and can be reused. Three extraction cycles did not affect the % recoveries of the studied pesticides. The % recoveries, obtained for chlorfenvinphos, diuron, endosulfan sulfate, chlropyrifos, and fenvelerate, ranged from 28 to 62%; linear range, 0.035 to 22 mg L À1 ; LOD, 37 to118 lg L À1 ; and LOQ, 123 to395 lg L À1 .

No abstract

A laboratory made chelating resin based on immobilization of fluorinated β-diketone group on styrene divinyl benzene was employed for the extraction and pre-concentration of trace metals in natural water samples before their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Extraction efficiency of the resin toward metal ions was examined by column procedure. Various experimental parameters consisting pH, sample loading flow rate, eluent concentration/volume and breakthrough limits were investigated for the effective uptake of metals on the resin. The resin capacity at pH (9) was found to be 10. 20, 9.13, 7.47, 8.67, 3.12, 6.45 and 9.80 mg g −1 for Cd (Cadmium), Co (Cobalt), Fe (Iron), Mn (Manganese), Mo (Molybdenum), Ni (Nickel) and Zn (Zinc), respectively. The method was applied for the extraction/pre-concentration of Cd, Co, Fe, Mn, Mo, Ni and Zn in natural water samples and their subsequent determination was carried out by ICP-OES. Percentage recoveries obtained for the selected metals except Mo were ≥95% under similar experimental conditions with <5% relative standard deviation. Alkali/alkaline earth metals, the major matrix ions were not retained on the resin, the resin is selective for trace metals, therefore it is suitable for the extraction of these metals in natural water samples for environmental and health-related studies. 

No abstract

No abstract