ELECTROKINETIC CHARACTERISTICS OF CALCINED KAOLINITE IN AQUEOUS ELECTROLYTIC SOLUTIONS

In this work, the electrokinetic characteristics of calcined kaolinite in aqueous solutions has been studied in the presence of the electrolytes of NaCl , KCl , NH 4 Cl , NaNO 3, MgCl 2, CaCl 2 and AlCl 3, through electrophoretic measurement. The experimental results have shown that the zeta potential was closely dependent on the valence and concentration of the electrolytic cations, but not on the type of the cations. The higher the valence and the concentration were, the stronger the impact to the zeta potential was. Al 3+ could reverse the potential sign from negative to positive. In addition, it was found that the monovalent anions of Cl - and [Formula: see text] made a big difference to the zeta potential at the same dosage.

ELECTROKINETIC STUDIES OF MINERALS IN AQUEOUS SOLUTIONS THROUGH ELECTROACOUSTIC MEASUREMENT

Electrokinetic property of various minerals in aqueous solutions has been studied through electroacoustic measurement in the present work. This study was carried out on the particles of calcite ( CaCO 3), magnetite ( Fe 3 O 4), quartz ( SiO 2), and galena ( PbS ) in an aqueous NaCl solution. Electrophoretic measurement was also applied to magnetite and quartz particles for the comparison of the two methods. The experimental results have shown that the point of zero charges (PZCs) of calcite, magnetite, and galena were at pH 12.5, 3.8 and 2.8, respectively, while no PZC for quartz appeared in the pH range of 1.5–11. The electroacoustic and electrophoretic measurements have obtained the same PZC and similar curves of zeta potential vs pH for magnetite and quartz particles in aqueous solutions. In addition, it has been found that a specific adsorption of Na + cation was applied to magnetite surfaces in aqueous solutions if the electrolyte ( NaCl ) concentration in the solution is high enough, leading the isoelectric point to shift rightward. This observation might be more remarkable in electroacoustic measurement than electrophoretic measurement.

Capillary electrophoretic measurement of tissue metabolites

A method for the measurement of tissue metabolites from rabbit urinary bladder using capillary electrophoresis (CE) has been developed. The method generates a reproducible electropherogram containing >20 peaks, including NAD, NADH, lactate, UDP-glucose, phosphocreatine, creatine, ATP, ADP, GTP, and UTP, from <20 nl of extract solution generated from 1.1 nl (or ∼1.2 μg) of tissue in <40 min. Multiple samples from the same bladder produce SE comparable with enzymatic or nuclear magnetic resonance (NMR) measurements of metabolites: phosphorus-NMR measurement requires 106 more tissue than CE; individual enzymatic measurements using 100 μl/sample require 2,000 μl, a 105 greater volume than required by CE for the same number of metabolites. CE detects about three times more peaks than phosphorus-NMR on a similar time scale. Comparable measurements using enzymatic analysis would require ∼10 times longer. The combination of minimal tissue volume requirements, rapid measurement, and reproducibility makes CE a valuable tool in the investigation of simultaneous changes in multiple metabolites from minute tissue samples.