Ultra-micro

Natelson, S. Routine use of ultra-micro methods in the clinical laboratory. Am. J. Clin. Path. (1951),... 

L. Olivier, N. Q. Ho, J. C. Grandidier, and M. C. Lafarie-Frenot, Characterization by Ultra-Micro Indentation of an Oxidized Epoxy Polymer, Pol. Degrad. Stab., 93,... 

Molecular and supramolecular devices incorporated into ultra-micro-circuits represent potential hardware components of eventual systems that might qualify as molecular computers, whose highly integrated architecture and operation would not be of the von Neumann type. On the biological side, the fabrication of components for sensory and motor protheses could be considered. All these entities may result from the self-assembly of suitably instructed subunits so that computing via self-assembly may be envisaged. 

Mechanisms of Actions of Macro-, Micro- and Ultra-Micro Elements Which are Included in Grinization Complexes... 

The ultra-micro-hardness of inorganic and organic salts has been measured for 15 substances. These are products usually produced in industrial crystallization. The hardness-force-dependency was examined and data are compared to those from literature. In the case of potassium nitrate a strong direction dependency of the hardness was observed. Also effects of impurities in the crystal lattice were analysed. In the end an attempt has been introduced to calculate the hardness of crystals from a physical model. 

For most substances used in the experiments an indentation force greater than 0.1 N leads to cracks or even lift-offs at the edges or the ends of the diagonals of the indentation produced by the Vickers pyramid. Therefore the values of the measured hardnesses have a large spread and usually are not reproducible. Most of the literature data were produced at a time where ultra-micro-hardness devices were not available, so that forces larger 5-10 N have been used. 

Recently a detailed study has been made of the methods required to obtain spectra of micro and ultra-micro amounts of sample 117). A focussing micro-illuminator is used for the detection of 1-10 micrograms of samples. Often, one can obtain the spectrum of impurities like fish-eyes in plastics by merely punching a hole the size of the imperfection in a masking material like cardboard and run the spectrum until the signal-to-noise level has reached a sufficient value to make an identification of the impurity. One can carry out a similar measurement in regions where the impurity appears to be absent and subtract the two spectra to enhance the spectra of the impurity relative to the more dominant polymer. 

Owing to the small current measured, Ohmic drop (also called IR-drop) effects in solution are much less pronounced. This includes that ultra-micro electrodes can be used in highly resistive media (including non-aqueous solution) and/or without the use of supporting electrolyte. 

Sobel, A. E., and A. Hanok Ultra Micro Quantitative Analysis in Clinical Laboratories. Mikrochim. Acta 39, 51 (1952). 

Haga, P. R. van Laboratory Table for Ultra-Micro-Techniques. Clin. Chim. Acta 8, 327 (1963). 

Alimarin, J. P., and M. N. Petrikova The Ultra-Micro Method of Chemical Analysis. II. The Electrolytic Separation. Zh. Analit. Khim. (Russ.) 5, 11 (1953) J. Anal. Chem. USSR (Engl. Transl.) 8, 11 (1953). 

Fig. 3.13 Popular ultra-micro electrode (UME) geometries, a radius of disk or finite conical electrode, r0 radius of hemispherical electrode, b inner radius of ring electrode, and c outer radius of ring electrode (after Zoski 2002)...

Pipetman Ultra Micro Pipette (French manufactured)... 

Hamilton Ultra Micro Syringe Pipet Hamilton Company P.O. Box 7500 Reno. NV 89502 4 H... 

Pipetman Ultra Micro Pipette (French manufactured) Analtech, Inc. 75 Blue Hen Drive Newark, DE 19711 12 1... 

When performing an analysis of the sample, the choice of method will be influenced by the quantity of sample available. The following terms refer to scale of working macro, semi-micro, micro and ultra-micro. 

Sasaki, M. (1964). An ultra-micro assay of serum cholinesterase with m-nitrophenol indicator. Rinsko Byori 12 555-8. 

Araki, S., Suzuki, S., Hobo, T., Yamada, M. Automated ion-exchange chromatography for the ultra-micro determination of alkali and alkaline-earth metals. Use of a double-jet hydrogen flame ionisation detector. Bunseki Kagaku 19, 493 (1970) AnaL Abstr. 21, 3235 (1971)... 

T. Takeuchi, D. Ishii, A. Saito, T. Ohki, Direct coupling of an ultra-micro-LC and a MS, J. HighResolut. Chromatogr. Chromatogr. Commun., 5 (1982) 91. 

Another device for automated development is the chamber constructed by Tyihak [4], in which the adsorbent layer is placed between two plates and the mobile phase flows under increased applied pressure. It can be operated in the linear or radial mode. Another automated device is the UMRC (Ultra Micro Rotation Chromatograph), where the eluent is delivered to the center of a rotating TLC plate [5]. A simple device was constructed by Delvorde and Postaire [6] in which the liquid is pumped out (by vacuum) which causes the flow of the mobile phase and decreases the vapor pressure. 

Mahoney E, Holt A, Swain M, Kilpatrick N The hardness and modulus of elasticity of primary molar teeth an ultra-micro-indentation study. J Dent 2000 28 589-594. 

Recent studies based on comparison between gel permeation chromatography and ultra/micro-filtration [119] have shown that whatever the chemical nature and shape of the model macromolecule used, it is possible to predict the cut-off value of a membrane by considering the hydrodynamic volume of the macromolecule. This parameter provides an appropriate definition of the effective solute size to be considered in hydrod)mamic models. 

Nl. Naftalin, L., and Stephens, A., A method for the determination of free plasma amino acids in ultra-micro quantities. Clin. Chim. Acta 12, 365-369 (1965). 

Sobel, A. E., Hirschman, A., and Besman, L., Estimation of ultra micro quantities of urea and Kjeldahl and aminoacid nitrogen. Anal. Chem. 19, 927-929 (1947). 

Separation operations are frequently classified according to the size of particles. No precise size definitions exist for terms such as ultra-, micro-, nano-, colloidal, and fine particle filtration. Different authors use different nomenclature in classifying separations in terms of size. A simplified classification is shown in Table 22.1. 

El, Exley, D., Detection of ultra-micro quantities of inorganic cations. Photoelec. Spectrometry, Group Butt. pp. 322-327 (1959). 

Sadek, F. S., and Reilley, C. N., Ultra-micro chelometric titration witir potentiometric end point detection. Microchem. J., 1, 183-201 (1957). 

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