and Yan (5) reported that they successfully separated high polarity explosives using CEC with nonporous C18-coated material and a mobile phase with a low concentration of organic modifier and SDS added to the mobile phase to increase the wettability of the particle surface. Zhang and colleagues (9) also reported that very polar compounds could be separated by mixed-packing CEC with a stationary...

in present research work, homogeneous anion exchange membranes based on polysulfone (qapsfs) were prepared via chloromethylation, amination and alkalization. in amination step, trimethylamine and n,n,n',n'-tetramethyl-1,6-hexanediamine were used as amination and crosslinking agents, respectively. the chloromethylated polysulfone was characterized by 1hnmr spectroscopy and chloromethylation degr...

heterogeneous proton exchange membranes (pem) are synthesized using the dry phase inversion technique. the casting solutions are prepared by dispersing a finely ground cation exchange resin particle in n,n-dimethylacetamide (dmac) solution of polyvinyl-chloride (pvc). results show that ion exchange capacity is increased with the addition of 1 %-wt nanosilica (from 0.14 to 0.27 meq/g) while it i...

Phase diagram of the spin-1 quantum Heisenberg model with both exchange as well as single-ion anisotropy is constructed within the framework of pair approximation formulated as a variational procedure based on the Gibbs-Bogoliubov inequality. In this form adapted variational approach is used to obtain the results equivalent with the Oguchi’s pair approximation. It is shown that the single-ion a...

Phase diagram of the spin-1 quantum Heisenberg model with both exchange as well as single-ion anisotropy is constructed within the framework of pair approximation formulated as a variational procedure based on the Gibbs-Bogoliubov inequality. In this form adapted variational approach is used to obtain the results equivalent with the Oguchi’s pair approximation. It is shown that the single-ion a...

A new poly(ionic liquid)-grafted silica stationary phase was prepared and characterized. It was then applied for multi-mode chromatographies, including ion-exchange, reversed-phase, and hydrophilic interaction liquid chromatographies for the effective separation of anions, hydrophobic compounds, and small polar molecules, respectively.

a hydrmetallurgical study based on the extraction of zn and pb from a nigerian sphalerite mineral leached with 4 m hydrochloric acid has been undertaken. triphenylphosphite (tpp) has proved to be very effective for the extraction of zinc. with 2 m tpp and at ambient temperature of 25±2°c; 35.71% and 66.7% of pb and zn were extracted, respectively, into the organic phase within 60 min. the recov...

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Ion exchange resins have been used to help formulate pharmaceuticals since the late 1950's. During that time they have proved to be safe and effective excipients and are now used in many commercial formulations throughout the world. In this article we will look at some of the common problems faced by formulators and how using ion exchange resins may be able to solve them. Ion exchange resins ar...