Magnetic susceptibility: instrumentation and analytical applications including bioscience, catalysis, and amorphous materials

Abstract

They had very limited stability in aqueous solution with a consequent loss of catalytic activity.This was changed with the introduction of immobilized enzymes (10-12). Free or water-soluble enzymes were immobilized or made insoluble by combination with some inert matrix either by entrapment or chemical reaction to ensure insolubility. In either case, it was shown that enzymes retained activity for long periods of time. Thus, it has been noted that a single sample of immobilized glucose oxidase has been used for several thousand determinations (10).The new developments and the proliferation of publications and patents on immobilized enzymes have led to widespread use and intensive work with automated instrumentation and enzyme electrodes. The high-speed and rather sophisticated instrumentation has, of course, been a tremendous asset in the clinical chemistry laboratory.Enzyme electrodes have probably been the most interesting application of immobilized enzymes. These electrodes have been the combination of an insoluble enzyme with some porous organic polymer which is used as a coating for an electrochemical sensor. These have been especially useful in such systems as whole blood or biological media, where sample preparation has been a major problem.The format of this article continues to be that which was used previously. Again, as was done in the last review, the enzyme nomenclature follows the recommendations of the International Commission of Enzyme Nomenclature (13). LITERATURE CITED(1) . M. Fishman and H. F.

Optimizing the Magnetic Response of Suspensions by Tailoring the Spatial Distribution of the Particle Magnetic Material

“…analytical chemistry, magnetic measurements-or magnetic field-responsive materials. [14][15][16] As a matter of fact, many of these magnetic field-responsive materials -e.g. field-responsive fluids, foams, elastomers or gels-are built by incorporating colloidal ferromagnetic particles to a diamagnetic matrix.…”

Magnetometry: aspects of instrumentation and applications including catalysis, bioscience, and geoscience

“…The crystal and molecular structure of Mnbiocomplex is presented. In our last review (57) we surveyed the interesting work on magnetic monopoles presented by Cope. Most of his work has been published in bio-oriented journals, and is likely to escape the attention of chemists and physicists.…”

“…As we pointed out in our earlier reviews (56,57), "amorphous magnetic materials" have attracted considerable attention because of their technological applications in the large-scale applications of magnetically soft materials for transformer cores and other electrical devices. Analytical chemists should note that such amorphous systems consist of metal-metalloid compositions, and their professional contribution to these relatively new materials lies not only in analyzing the elemental composition but most importantly in measuring the magnetic parameters, such as the remanent magnetization (<rr) the coercive force (Hc) and finally the magnetic energy product (B-H).…”

“…It has been well established that magnetometry has proved to be extremely useful in the characterization of these systems at the microand macroscopic levels, dealing with their electronic and bulk structures, analysis of various components present, and so on. The first eleven reviews on "Magnetic Susceptibility" appeared during 1962 to 1982 (39,(49)(50)(51)(52)(53)(54)(55)(56)(57). This 1984 version covers L. N. Mulay Is a professor of Solid Stale Science In the Materials Science and Engineering Department at the Pennsylvania State University since 1967 and served as chairman of the corresponding interdisciplinary program from 1967 to 1972.…”

Measurement and Modelling of Gradient Magnetic Fields for Bio-Chemical Separation Processes

“…Advantages of gradient magnetic fields for intensification of heat and mass transfer processes that occur especially in catalytic reactors have been presented in the literature [20], [21], [22]. Furthermore, the effects of gradient magnetic fields on the acceleration of chemical processes on water and other chemical suspensions at the molecular level have also been presented in the literature [23], [24], [25], [26], [27], [28], [29].…”