No abstract

A new separation and preconcentration procedure based on cloud point extraction was developed for arsenic trace analysis using inductively coupled plasma optical emission spectrometry. Arsenic in + 5 oxidation state was complexed with ammonium molybdate, Triton X-100 was used as a surfactant. Optimal parameters such as pH value and Triton X-100 concentration were determined. Phase separation was induced by adding a salting-out agent to avoid an analyte loss because of temperature changes. The combination of Triton X-100 with ammonium sulphate as a salting-out agent was firstly sug-gested as an extraction system for arsenic quantification. Conditions for arsenic (III) into arsenic (V) oxidation were established. The proposed procedure was successfully applied for arsenic quantification in a gadolinium based magnetic resonance imaging (MRI) contrast agent gadobutrol at the level indicated in the guideline for elemental impurities approved by International council for harmonisation of technical requirements for pharmaceuticals for human use (ICH Q3D) as a limit concentration.

Ion-imprinted divinylbenzene and methacrylic acid copolymers for rare-earth element adsorption with crosslink ratios 60 and 40% have been synthesized. Ion imprinting has been carried out via the trapping approach. Alizarin red S has been incorporated in the polymers as a nonvinylated ligand. The obtained materials were characterized via scanning electron microscopy and Fourier transform infrared spectroscopy. Synthesized polymers exist as gel-type nonporous spherical agglomerates from 2 to 6 μm with low surface areas. The sorption properties of the synthesized polymers with respect to lanthanides in static and dynamic modes have been studied. The most efficiently synthesized materials extract rare earth elements from solutions at pH 4−7. The maximum sorption capacity of the obtained polymers with regard to Gd is around 0.5 mmol/g. According to the obtained results, the imprinted polymer with a crosslink ratio 60% is characterized by the highest values of distribution coefficients for lanthanides. The total lanthanide breakthrough capacity for this polymer is 0.861 μmol/g. The adsorption column has been constructed using the imprinted polymer with a crosslink ratio 60%. The column extraction and preconcentration procedure for the trace Eu content determination in the strontium iodide recycled material by inductively coupled plasma−atomic emission spectrometry at a level of 1 × 10 −6 % (mass) has been proposed.

Macroporous copolymers of ethylene glycol dimethacrylate and methacrylic acid containing immobilized molecules of Alizarin red S and similar polymers imprinted by gadolinium ions were synthesized by free radical bulk polymerization method. Sorption properties of two pairs of the polymers with cross-link ratio of 85.7 and 92.6% were compared. The resulting materials were characterized by scanning electron microscopy and infrared spectroscopy. Sorption performance of the polymers synthesized toward gadolinium ions was investigated. It has been found that the maximum removal of gadolinium ions from solutions is observed at pH 6. The experimental data on gadolinium ion interaction with the sorbent surface were shown to fit Langmuir adsorption theory. Maximum gadolinium sorption capacity of nonimprinted polymers with cross-link ratio of 85.7 and 92.6% is 19.4 and 14.9 mg/g, respectively. Sorbent selectivity for rare earth ions was studied. According to the obtained results, sorbents under study reveal