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In this work magnetic cellulose xanthate was prepared with two different routes, i.e., fabrication of Fe 3 O 4 @ cellulose followed by preparation of xanthate, and a one step approach by adding iron source to cellulose xanthate solution. The cellulose acts as both as reducing agent to convert Fe 3+ ions to Fe 2+ and template for growth of Fe 3 O 4 . The prepared composites were characterized by SEM, XRD, VSM, EDS, TGA, and FT-IR techniques. Magnetic sorbents were applied for adsorption of silver from acidic medium, and results revealed that the one step prepared composite has better performance in comparison with Fe 3 O 4 @cellulose xanthate, as the maximum adsorption capacity within 5 min extraction time was 166 and 15.6 mg g −1 , respectively. The relative selectivity factor (α r ) of Ag + with respect to other cations, such as Zn 2+ , Cr 3+ , Co 2+ , Ni 2+ , Pb 2+ , and Pd 2+ , is 252, 74.8, 2543, 924, 3837, and 26.6, respectively. Moreover, the reusability of the sorbent was investigated by elution the adsorbed ions with 3.0 mL of 0.4 mol/L Na 2 S 2 O 3 solution. It was found that the recovery was (90−97%) after 3 cycles of sorption and desorption. Finally this method was applied to analyze the silver ions in tap water, dental radiology agent, and synthetic samples.

The application of the recently developed area correlation constraint in Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) for the quantitative determination of analyte mixtures is shown. The feasibility of the proposed constraint is tested firstly for the calibration and quantitation of PAHs mixtures in their synthetic mixtures (validation samples) and in river water samples dissolved organic matter (DOM) using EEM fluorescent three-way data. In this case, MCR-ALS results obtained with the proposed area correlation constraint are comparable with the results obtained with methods based on the fulfillment of the trilinear model, like PARAFAC and MCR-ALS with the trilinearity constraint. Secondly, the possibility of applying this new area correlation constraint is extended to the analytical determination of lipid mixtures in synthetic and cell culture samples by LC-MS, where the trilinear model does not hold.The applicability of the proposed area correlation constraint is assessed, and it is proposed as a general tool for the quantitative determination of unknown mixtures of analytes in complex natural samples with severe profile overlapping and unknown composition, whatever the data structure is.

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A novel organo-nanoclay, i.e., diclofenac modified montmorillonite was used as a green and selective support for the adsorption of Pd(II) ions from aqueous solution. The diclofenac-montmorillonite composite was prepared and characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Batch experiments were carried out with an equilibrium time of 30 min and the kinetics models of the interaction were studied. The selectivity of the sorbent towards Pd(II) was extremely good at a pH of 6.0-7.0, while the adsorption of other cations was low. The adsorption data were measured at room temperature and the yielded Langmuir monolayer capacity was 20.0 mg g À1 . The adsorption reaction was exothermic and the thermodynamic parameters, DH, DS and DG, at room temperature were À34.37 kJ mol À1 , À116.56 J K À1 mol À1 , and +0.96 kJ mol À1 , respectively. The specific surface area increased from 35.8 m 2 g À1 to 80.6 m 2 g À1 for the modified clay, suggesting that intercalation creates a porous framework thereby increasing the surface area and increasing the selectivity of this sorbent for the adsorption of Pd(II) ions. In order to evaluate the applicability of this support for the uptake of palladium from complex matrices, different real samples such as: road dust, rice, urine and water samples were analyzed.

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In this work, magnetic Fe 3 O 4 nanoparticles (NPs) were synthesized by ultrasonic chemical co-precipitation method. Then hydrophobic ionic liquid (IL), as a green coating agent, was deposited on the surface of synthesized NPs in order to improve their extraction capability toward Pd(II) ions as diethyldithiocarbamate (DDTC) complex. Scanning electron microscopy, thermogravimetric analysis, X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Fourier transformed infrared (FTIR) techniques were used for characterization of the adsorbent. The adsorption rate was fast and the equilibrium time was achieved within 4 min due to the strong interaction of Pd-DDTC complex with the IL and the absence of internal diffusion resistance. The separation of the adsorbent from aqueous bulk was achieved after about 2 min by a magnet, so no centrifugation or filtration was required. The effective parameters such as pH, concentration of ligand, amount of adsorbent, and the extraction time were inspected by using a central composite design in order to identify the most important parameters and their interactions. Under optimum conditions, the detection limit was 0.82 ng mL −1 and the relative standard deviation (n = 10) was 2.8% for 100 ng mL −1 of Pd(II). The proposed method was applied for the preconcentration of Pd(II) from road dust, liver, and water samples, and it was found that the amounts of palladium ions in dust and liver samples were 104 and 8.7 ng mL −1 , respectively.