Analytical characterization of a silica gel sorbent with thioetheric sites

Nanoadsorbents: Classification, Preparation, and Applications (with Emphasis on Aqueous Media)

“…The chemical modification of silica’s surface by immobilization of functional groups has been reported for extractive concentration of metal ions. , Zhang et al investigated the determination of trace metals in natural samples after preconcentration on modified silica gel and on modified silica nanoparticles. Silica gel and nanometer SiO 2 modified with 4-(2-aminoethylamino)- N -(2-(2-aminoethyl amino)ethyl) butanamide (SG-AAEB and nanometer SiO 2 -AAEB), which were prepared based on chemical immobilization, were used as sorbents for the solid phase extraction of Cu(II), Fe(III), and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES).…”

Solid phase extraction of gold(III) on silica gel modified with benzoylthiourea prior to its determination by flame atomic absorption spectrometry

“…Hence, the sorption capacity was found to be 0.92 ± 0.04 mmol g −1 for Au(III) for three parallel works. Gold(III) could be most probably coordinated to a free electron pair of sulfur and oxygen atom of the benzoylthiourea group as suggested before for silica gel sorbent with thioetheric sites (Gentscheva et al 2007). Au(III) can react with active sites of benzoylthiourea at a 1:1 ratio, on the basis of ligand content on the sorbent.…”

“…In recent years, separation and preconcentration methods for gold have been reported, in which the common adsorbents of gold were ligandmodified silica gel (Komendova-Vlasankova and Sommer 2002;Hajkova et al 2000;Gentscheva et al 2007;Pu et al 1998;Liu et al 2000a), activated carbon (Chakrapani et al 2001, Nakbanpote et al 2000, and chelating resin with selective functional groups such as sulfur phosphorus resin (Sanchez et al 2001), and macroporous resin containing imidazoline groups (Su et al 1995), aminoguanidinyl group containing polymeric matrix (Jermakowicz-Bartkowiak and Kolarz 2002), diol anchored poly(p-CMS-DVB) micro beads (Kavakli et al 2006), chitosan resin (Chang and Chen 2006) and modified chitosan resin (Fujiwara et al 2007).…”

A perspective on diverse adsorbent materials to recover precious palladium and the way forward

“…108 Silica and alumina have been studied for sequestering metal ions. 109,110 These mesoporous materials are endowed with relatively low cost, good thermal, mechanical stability and higher catalytic performance. 110,111 Mesoporous silica such as SBA-15 (Santa Barbara Amorphous) has evinced more attention in recent years in view of their higher pore volumes, huge surface area and tunable pore size.…”