scholarly journals Self‐Assembled Anion‐Binding Cryptand for the Selective Liquid–Liquid Extraction of Phosphate Anions

2020 ◽  
Vol 132 (46) ◽  
pp. 20660-20664
Author(s):  
Rebecca Andrews ◽  
Sabera Begum ◽  
Christopher J. Clemett ◽  
Robert A. Faulkner ◽  
Michael L. Ginger ◽  
...  
Keyword(s):  
Liquid Extraction ◽  
Anion Binding ◽  
Liquid Liquid Extraction ◽  
Phosphate Anions ◽  
Self Assembled

scholarly journals Self‐Assembled Anion‐Binding Cryptand for the Selective Liquid–Liquid Extraction of Phosphate Anions

2020 ◽  
Vol 59 (46) ◽  
pp. 20480-20484
Author(s):  
Rebecca Andrews ◽  
Sabera Begum ◽  
Christopher J. Clemett ◽  
Robert A. Faulkner ◽  
Michael L. Ginger ◽  
...  
Keyword(s):  
Liquid Extraction ◽  
Anion Binding ◽  
Liquid Liquid Extraction ◽  
Phosphate Anions ◽  
Self Assembled

scholarly journals Highly Efficient, Tripodal Ion-Pair Receptors for Switching Selectivity between Acetates and Sulfates Using Solid–Liquid and Liquid–Liquid Extractions

2020 ◽  
Vol 21 (24) ◽  
pp. 9465
Author(s):  
Marta Zaleskaya ◽  
Łukasz Dobrzycki ◽  
Jan Romański
Keyword(s):  
Binding Sites ◽  
Liquid Extraction ◽  
Ion Pair ◽  
Anion Binding ◽  
Binding Modes ◽  
Anion Receptor ◽  
X Ray ◽  
Liquid Liquid Extraction ◽  
Solid Liquid Extraction ◽  
Solid Liquid

A tripodal, squaramide-based ion-pair receptor 1 was synthesized in a modular fashion, and 1H NMR and UV-vis studies revealed its ability to interact more efficiently with anions with the assistance of cations. The reference tripodal anion receptor 2, lacking a crown ether unit, was found to lose the enhancement in anion binding induced by presence of cations. Besides the ability to bind anions in enhanced manner by the “single armed” ion-pair receptor 3, the lack of multiple and prearranged binding sites resulted in its much lower affinity towards anions than in the case of tripodal receptors. Unlike with receptors 2 or 3, the high affinity of 1 towards salts opens up the possibility of extracting extremely hydrophilic sulfate anions from aqueous to organic phase. The disparity in receptor 1 binding modes towards monovalent anions and divalent sulfates assures its selectivity towards sulfates over other lipophilic salts upon liquid–liquid extraction (LLE) and enables the Hofmeister bias to be overcome. By changing the extraction conditions from LLE to SLE (solid–liquid extraction), a switch of selectivity from sulfates to acetates was achieved. X-ray measurements support the ability of anion binding by cooperation of the arms of receptor 1 together with simultaneous binding of cations.

Comparison of Sorption and Extraction Methods for Recovery of Trace Organics from Water

1983 ◽  
Vol 15 (6-7) ◽  
pp. 149-159 ◽  
Author(s):  
V C Blok ◽  
G P Slater ◽  
E M Giblin
Keyword(s):  
Solvent Extraction ◽  
Methylene Chloride ◽  
Extraction Methods ◽  
Liquid Extraction ◽  
Standard Mixture ◽  
Liquid Liquid Extraction ◽  
Trace Organics ◽  
Tenax Gc

Several commercially available adsorbents were compared with solvent extraction methods for their utility in recovering trace organics from water. The adsorbents examined included Amberlite XAD-2, XAD-4 and XAD-8, Ambersorb XE340 and XE348 and Tenax-GC. All were found to produce high artifact levels, even after extensive clean-up, making them unsuitable for the analysis of trace organics in water. Quantitatively, Likens-Nickerson or continuous liquid-liquid extraction with méthylene chloride gave better recoveries than the adsorbents. Qualitatively, extractive methods were preferred as they yielded much lower levels of impurities than the adsorbents. These methods of recovering trace organics were evaluated using a standard mixture of compounds added to the water at a level of 55 µg/l. Likens-Nickerson extraction gave comparable recoveries of this mixture at 55 µg/l and 11 µg/l.

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