Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

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A rapid method was developed for separation, pre-concentration and sequential determination of antimony, bismuth, tin and mercury by flow injection solid phase extraction coupled with on-line chemical vapor generation electrothermal atomic absorption spectrometry. The system is based on chelating/cationic retention of the analytes onto a mini-column filled with a mesoporous silica functionalized with 1,5 bis(di-2-pyridyl)methylene thiocarbohydrazide. Several variables (sample flow rate, eluent flow rate, eluent concentration and reductant concentration) were considered as factors in the optimization process. Interactions between analytical factors and their optimal levels were investigated using three central composite designs. The optimized operating conditions were: sample pH ¼ 2.2, sample flow rate 3 mL min À1 , eluent flow rate 2.5 mL min À1 , eluent 3.1% HCl for Sb, Bi and Sn, and 4.6% thiourea for Hg, and 0.6% NaBH 4 reductant. The optimum conditions established were applied to the determination of Sb, Bi, Sn and Hg in sea water and river water by flow injection solid phase extraction coupled with on-line chemical vapor generation high resolution continuum source electrothermal atomic absorption spectrometry (FI-SPE-CVG-CS ETAAS). For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TM 24.3 and TMDA 54.4, Fortified Lake Waters was addressed. The results showed good agreement with the certified values.

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