Hydrogen isotope exchange between fluoroform (CF3H) and water. 3. Catalysis by −OH-type anion exchange resins, and the effect of added dimethyl sulfoxide

1983 ◽  
Vol 61 (6) ◽  
pp. 1301-1305 ◽  
Author(s):  
E. Allan Symons ◽  
John H. Rolston ◽  
Lorraine A. Baldisera ◽  
John C. G. Drover ◽  
J. Douglas Bonnett
Keyword(s):  
Anion Exchange ◽  
Hydrogen Isotope ◽  
Ion Solvation ◽  
Hydroxide Ion ◽  
Anion Exchange Resins ◽  
Resin Beads ◽  
Observed Behaviour ◽  
Pore Liquid ◽  
Exchange Resins ◽  
Aqueous Slurry

Anion exchange resins like Rexyn 201(OH) and Amberlyst A-26 have been shown to be active catalysts for deuterium transfer between water and fluoroform. Under stirred slurry conditions at 50 °C the Rexyn 201 is 25 × more effective than NaOH on a per-hydroxide-ion basis. Addition of DMSO to the aqueous slurry produces an increase in Rexyn 201 reactivity, but the resin advantage over homogeneous −OH declines to zero by ~30 mol% DMSO. At 70 mol% DMSO the resin is less effective by a factor of ~100. Local fluoroform solubility and hydroxide ion solvation effects, including phase separation, in the pore liquid of the resin beads appear to be responsible for the observed behaviour.

Comparison of cation/anion exchange resin methods for multi-element testing of acidic soils

Soil Research ◽  
1994 ◽  
Vol 32 (2) ◽  
pp. 229 ◽  
Author(s):  
MJ Mclaughlin ◽  
PA Lancaster ◽  
PG Sale ◽  
NC Uren ◽  
KI Peverill
Keyword(s):  
Anion Exchange ◽  
Chemical Methods ◽  
Simultaneous Extraction ◽  
Extraction Procedures ◽  
Anion Exchange Resins ◽  
Resin Beads ◽  
Resin Membrane ◽  
Exchange Resins ◽  
Time Required ◽  
Bead Method

Increasing laboratory costs and time constraints have stimulated development of techniques which allow the simultaneous extraction of many elements from soil. We assessed several techniques using cation/anion exchange resins which allow the simultaneous extraction of Ca, Mg, K, Al, Mn and P from soil. Elements are extracted by shaking soil either with resin beads or resin membranes in distilled water. The resin is separated from the soil and elements are desorbed using BaCl2/HCl. Concentrations of elements in solution are then determined by conventional chemical methods. Using 50 soils which varied in acidity/fertility, a comparison was made between concentrations of elements extracted by the resin methods and commonly used extraction procedures. Apart from Al, concentrations of elements extracted by the resin procedures correlated well with conventional extraction procedures, although P was less well correlated (R2 < 0.8) than cations (R2 > 0.8). All the resin procedures have the potential to reduce the time required for analysis of Ca, Mg, K, Mn and P in soils. The resin membrane method offers considerable speed and cost advantages over the unconfined resin bead method.

Removal of Hydrophobic and Hydrophilic Constituents by Anion Exchange Resin

1999 ◽  
Vol 40 (9) ◽  
pp. 207-214 ◽  
Author(s):  
J.-P. Croué ◽  
D. Violleau ◽  
C. Bodaire ◽  
B. Legube
Keyword(s):  
Molecular Weight ◽  
Anion Exchange ◽  
Water Source ◽  
Atomic Ratio ◽  
Size Exclusion ◽  
Salting Out ◽  
Anion Exchange Resins ◽  
Hydrophilic Character ◽  
Exchange Resins

The objective of this work was to compare the affinity of well characterized NOM fractions isolated from two surface waters with strong (gel matrix and macroporous matrix) and weak anion exchange resins (AER) using batch experiment conditions. The structural characterization of the fraction of NOM has shown that the higher the hydrophilic character, the lower the C/O atomic ratio, the lower the SUVA, the lower the aromatic carbon content and the lower the molecular weight. In general (not always), strong AER was more efficient to remove DOC than weak AER. For the same water source (Suwannee River), the higher the molecular weight of the NOM fraction, the lower the affinity with AER. Increasing the ionic strength favored the removal of the hydrophobic NOM fraction (“salting out” effect) while increasing the pH apparently reduced the removal of the hydrophilic NOM fraction. Results were discussed in terms of size exclusion, adsorption, anion exchange and also hydrophobic/hydrophilic repulsion.

scholarly journals Impact of anion exchange adsorbents on regional citrate anticoagulation

2020 ◽  
pp. 039139882094773
Author(s):  
Karin Strobl ◽  
Stephan Harm ◽  
Ute Fichtinger ◽  
Claudia Schildböck ◽  
Jens Hartmann
Keyword(s):  
Anion Exchange ◽  
Regional Citrate Anticoagulation ◽  
Liver Support ◽  
Anion Exchange Resins ◽  
Increased Risk ◽  
Extracorporeal Liver Support ◽  
Target Molecules ◽  
Exchange Resins ◽  
The Impact

Introduction: Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations. Methods: Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption. Results: Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment. Conclusions: The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

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