A Specific Synergistic Effect in Ionic Liquid Chelate Extraction Based on Neutral Ternary Chloro-complex Formation

Enhanced Retention of Chelating Reagents in Octadecylsilyl Silica Phase by Interaction with Residual Silanol Groups in Solid Phase Extraction of Divalent Metal Ions

“…1 The performances of a variety of extraction systems, each consisting of an extracting reagent and an extraction solvent, have been studied, so that a suitable extraction system is selectable for each general application. Extracting reagents with novel selectivities have been extensively developed, while alternative media for organic solvents such as ionic liquids [2][3][4][5] and supercritical fluids 6 have been lately studied by taking into account their harmful effects on the environment. Solid-phase extraction (SPE) of metal ions using octadecylsilyl silica (ODS) has also been developed in this respect.…”

Formation of Minimal Third Phase in Ionic Liquid Extraction System with Trioctylphosphine Oxide and Its Possible Application to Extraction Concentration

“…After pipetting 20 mm 3 of the liquid phase and adding it to 5.0 cm 3 of an aqueous solution (pH 3.0) (Fig. 3A), 40 mm 3 of C4mimTf2N was added. The liquid phase became unified with the IL phase and sank under the aqueous phase (Fig.…”

“…Ionic liquids (ILs) have attracted attention as novel fluid media and hydrophobic ILs, including 1-alkyl-3-methyl imidazolium hexafluorophosphates (CnmimPF6) and bis(trifluoromethanesulfonyl)imides (CnmimTf2N), have often been used as an extraction solvent in solvent extraction for metals. [1][2][3][4][5][6] Trioctylphos phine oxide (TOPO) is a well-known lipophilic monodentate Lewis base, and is often used in traditional metal extraction as an extractant or a synergistic agent. Also in the IL extraction, the possible use of TOPO has been energetically investigated.…”

Synergistic Ion-pair Extraction of Strontium Ion with Tri-n-octylphosphine Oxide and Dicyclohexano-18-crown-6

“…In the extraction of Sr, however, TOPO has been used only as a synergistic extraction agent for its chelate extraction. [10][11][12] Our research group has investigated various IL extraction research for metals [13][14][15][16][17][18] including Sr. 19,20 In our fundamental investigation of several extraction separation techniques using a cyclohexane/water/IL triphasic system, 21 we found a clue that two neutral extractants, TOPO and dicyclohexano-18-crown-6 (DC18C6), may show some unique synergistic effect in ion-pair extraction of Sr into cyclohexane using bis(trifluoromethanesulfonyl)imide (Tf2N -), which is well known as an IL anion, as counteranion. In previous, only limited paper 22 was published on the synergistic effect of TOPO and a crown ether with suitable cavity; the researchers discuss ion-pair extraction of silver(I) (ionic radius = 129 nm) into chloroform with TOPO, dibenzo-18-crown-6 and picrate.…”