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In the present study, trace amount of nickel (II) ions in real samples has been separated, preconcentrated and determined by a synthesized nanocomposite. Our suggested nanocomposite was prepared by immobilization of 2-aminopyrimidine on nanocellulose. The properties of nanocomposite were characterized by TEM, TGA, elementalanalysis CHNS, EDS, and BET techniques. The effective factors such as pH, nanocomposite amount, extraction time, eluent type, ionic strength and sample volume were optimized for quantitative determination of nickel (II) ions. The linear range of the calibration graph was between 5 and 500 ng mL-1 with limit of detection (LOD) 2.33 ng mL-1. Relative standard deviations (RSD) were 2.33%. Modified nanocellulose was used for measurement of the trace amounts of Ni (II) ions in the real samples such as human blood and urine with suitable fallouts. [ABSTRACT FROM AUTHOR]

Towards determination of trace amount of bismuth (III) ions in real samples, we used cellulose/CBIMMT-resulted-ligand nanocomposite for its preconcentration and separation. The proposed nanocomposite was synthesized by immobilization of a ligand resulted by 4-(4′-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole (CBIMMT) on nanocellulose. The properties of resulted nanocomposite were characterized by TEM, TGA, EDS, elemental analysis CHNS, and BET methods. Moreover, the density functional theory (DFT) was used to deep understanding the changes in the electronic structure of above-mentioned ligand upon Bi(III) adsorption. The most energetically favorable position of adsorption is achieved and the value of adsorption is calculated to be −543.5 kJ/mol that is indication of chemisorption. It is found that the charge distribution of ligand changes significantly upon Bi (III) surface interaction. The operational features such as pH, nanocomposite quantity, extraction time, eluent kind, ionic power and the volume of the sample were optimized for quantifiable determination of bismuth (III) ions. The calibration graph shows a linear range of Bi (III) between 10 and 500 ng mL−1 with the detection limit of 2.68 ng mL−1. The RSD was calculated to be 1.5%. The proposed nanocomposite was utilized as a sensitive sensor of bismuth (III) ions in the real samples. Unlabelled Image • Functionalization of nanocellulose with CBIMMT-resulted ligand • Determination of Bi (III) at ng mL−1 levels using this nanocomposite • The electronic structure of the ligand is strongly influenced by Bi adsorption. • The synthesized nanocomposite is very sensitive and selective towards Bi ions. [ABSTRACT FROM AUTHOR]

• The results of study demonstrate that a very sensitive method could be achieved by the development SPE method. • High preconcentration factor was obtained easily through this method and a detection limit at sub ng mL−1 level was achieved. • In this method preparation time as well as consumption of toxic organic solvents was minimized without affecting the sensitivity of the method. • The proposed method has been applied to the determination of Mn (II) ions at trace levels in real samples such as natural water and wastewater samples with satisfactory results. In order to preconcentrate and clarify the trace amounts of Mn (II) ions, a very efficient natural adsorbent was prepared by cellulose nanofiber and its modification of the surface. Cellulose nanofibers were made by wood pulp hydrolysis using a concentrated acid under sonicating and reflux conditions and modification by dithizone immobilization. The influential elements like pH of extraction, the quantity of nanocomposite, time of extraction, the ionic power and typical volume were made better for numerical clarification of Mn (II) ions. According to findings, there is a linear range for the optimized technique between 1.0 and 15 ng mL−1 by the detection limit of 0.29 ng mL−1. As shown by statistical analysis of the results, there are small intra- and inter-day precision values from 0.8 to 2.7% and 1.6–5.4%, respectively, high pre-concentration factor and enrichment factor. It was found that the maximum adsorption capacity of the nanosorbent is 137 mg g−1. High selectivity and sensitivity were observed in the nanocomposite in terms of detection of low Mn (II) ions concentration at the ng mL−1 level with high precision for the samples. [ABSTRACT FROM AUTHOR]

• SBA-15 was modified by dithiooxamide ligand using a simple method. • The dithiooxamide/SDS/SBA-15 nanocomposite is selective towards removal of cobalt (ll). • The surface of synthesized nanocomposite was investigated by TEM, BET, CHNS and TGA analyses. • The Freundlich isotherm showed better results than the Langmuir isotherm. • The negative variations of ΔG and the positive variations of ΔH was found for Co (II) adsorption. In this study, mesoporous SBA-15 was functionalized by dithiooxamide ligand through sodium dodecyl sulfate as intermediate. The obtained nanocomposite was considered as a strong adsorbent towards selective removal of the cobalt (II) ions from the industrial wastewater samples. Transmission Electron Microscopy (TEM) analysis, Brunauer-Emmett-Teller (BET) analysis, elemental CHNS (carbon, hydrogen, nitrogen, and sulfur) analysis, and thermo-gravimetric analysis (TGA) were used for characterization, particle size determination, confirming the presence of the used ligand, and measuring the nanocomposite stability, respectively. Effective parameters on the removal of the cobalt (II) ions such as pH, adsorbent dosage, concentration, and contact time have been evaluated. Results showed that the Freundlich isotherm has a bit better correlation coefficient compared to Langmuir isotherm (0.96 versus 0.94, respectively). The maximum amount of Co (II) ions adsorption on 1 g of nanocomposite (q m) is calculated to be 2500 mg/g that points to the excellent adsorption. Kinetic analyses were conducted using pseudo-first and second-order models and the regression results showed that the pseudo-second-order model is more accurate for the study of the cobalt adsorption due to the higher correlation coefficient (0.99 versus 0.83) compared to the pseudo-first-order model. The result of the present study points that the suggested nanocomposite can be positively used in treating industrial effluents containing cobalt ions. [ABSTRACT FROM AUTHOR]