Azocalix[4]pyrrole Amberlite XAD-2: New polymeric chelating resins for the extraction, preconcentration and sequential separation of Cu(II), Zn(II) and Cd(II) in natural water samples

Preparation of porous nano-calcium titanate microspheres and its adsorption behavior for heavy metal ion in water

“…The Langmuir equation is applicable to homogeneous sorption, where the sorption of each sorbate molecule onto the surface has equal sorption activation energy. The logarithmic expression of the Freundlich equation is [18] ln q e = ln K F + 1 n ln C e (2) where q e is the equilibrium metal ion concentration on the adsorbent (mg g −1 ), C e is the equilibrium metal ion concentration in solution (mg L −1 ), and K F (L mg −1 ) and n are the Freundlich constants for adsorption capacity and adsorption intensity, respectively, and which are characteristics of the system. The Freundlich equation is employed to describe heterogeneous systems and reversible adsorption and is not restricted to the formation of monolayers.…”

“…SPE techniques offer high enrichment factor, rapid phase separation, low-cost and lower organic solvent consumption as well as the ability to combine with different detection techniques in on-line or off-line mode. The main solid-phase extraction sorbents are chelating resin [2,3], modified silica [4,5], active carbon [6] and carbon nanotubes [7]. Solid-phase extractions, based on nanoparticulate metal oxides such as TiO 2 and Al 2 O 3 , have particularly been found to have very high enrichment capacity for separation and preconcentration of metal ions from environmental water [8][9][10][11][12].…”

A New Thioamide Derivative for Separation and Preconcentration of Multi Elements in Aquatic Environment by Cloud Point Extraction

“…Due to the low concentration of these metals in the environmental and biological samples and interfering effects, a preconcentration/separation technique is generally necessary prior to the determination. For this purpose, various analytical procedures have been used, such as adsorption on activated carbon [3,4] co-precipitation [5,6] column extraction [7,8] ion-selective electrode [9,10] liquid-liquid extraction (LLE) [11] and cloud-point extraction (CPE) [12][13][14][15][16][17][18][19][20][21][22].…”

Octa-<i>O</i>-Methoxy Resorcin [4] Arene Amberlite XAD-4 Polymeric Chelating Resin for Solid Phase Extraction, Preconcentration, Separation and Trace Determination of Ni(II), Cu(II), Zn(II) and Cd(II) Ions

“…The nitration of Amberlite XAD-4 beads, the reduction of the nitrated resin and the subsequent diazotization of the amino resin was carried out by the procedure reported earlier for Amberlite XAD-2 [84]. The resulting diazotized resin was allowed to react with octa-O-methoxy resorcin [4] arene (1.0 g dissolved in 50 mL of 10% NaOH) at 0˚C -5˚C for 48 h. The dark brown coloured beads were filtered, successively washed with double distilled water and finally dried for further studies.…”