Synthesis of Carrier Ampholytes for Isoelectric Focusing Containing Sulfonic and Phosphonic Acid Groups Covering a Wide pH Range

1977 ◽  
pp. 111-120 ◽  
Author(s):  
Jaesool Shim ◽  
Prashanta Dutta ◽  
Cornelius F. Ivory

Ampholyte based isoelectric focusing (IEF) simulation was conducted to study dispersion of proteins in a horseshoe microchannel. Four model proteins (pls = 6.49, 7.1, 7.93 and 8.6) are focused in a 1 cm long horseshoe channel under an electric field of 300 V/cm. The pH gradient is formed in the presence of 25 biprotic carrier ampholytes (ΔpK = 3.0) within a pH range of 6 to 9. The proteins are focused at 380 sec in a nominal electric field of 300 V/cm. Our numerical results show that the band dispersions of a protein are large during the marching stage, but the dispersions are significantly reduced when the double peaks start to merge. This rearrangement of spreading band is very unique compared to linear electrokinetic phenomena (capillary electrophoresis, zone electrophoresis or electroosmosis) and is independent of channel position and channel shape. Hence, one can perform IEF in complex geometries without incorporating hyperturns.


2011 ◽  
Vol 183-185 ◽  
pp. 616-620
Author(s):  
Jun Feng Zhu ◽  
Guang Hua Zhang ◽  
Zhuo Miao ◽  
Shan Shan Yang ◽  
Bo Zhou

The hydrated cerium oxide (CeH) was synthesized and it was loaded on amino methylene phosphonic acid resin (APAR) to form the hybrid adsorbent CeH-APAR. The structure and thermal properties of CeH-APAR were tested by FTIR and TGA. And then, it was investigated that pH values and temperatures affected the adsorption property of CeH and CeH-APAR for fluoride ion. The results showed that CeH-APAR hybrid sorbent formed by Ce4+ and APAR with coordination bond is relatively stable below 270°C. Its adsorption property is similar to that of CeH, i.e. it is less affected by pH value, so it can be used in a wide pH range. Besides, under a stable pH, adsorption capacity of CeH-APAR also increases along with increasing temperature. As a result, it is a temperature-controlled sorbent and belongs to chemical adsorption.


1973 ◽  
Vol 73 (3) ◽  
pp. 483-488 ◽  
Author(s):  
F. Adlkofer ◽  
H. Schleusener ◽  
L. Uher ◽  
A. Ananos ◽  
C. Brammeier

ABSTRACT Crude IgG of sera from 3 patients with Graves' disease, which contained LATS-activity and/or thyroid antibodies, was fractionated by isoelectric focusing in a pH-range between 6.0 to 10.0. LATS-activity was found in IgG-subfractions from pH 7.5 to 9.5, thyroglobulin antibodies and thyroid microsomal antibodies from pH 6.0 to 10.0. It was not possible to separate LATS-activity from the thyroid antibodies by this technique. The results indicate that LATS and the thyroid antibodies are heterogeneous and of polyclonal origin.


1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.


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