Microscopy, applications

For some dosage forms and applications, microscopy with image analysis may be the method of choice. For instance, topical suspensions containing a number of sohd excipients make it difficult to directly measure the particle size of the drag substance. Measurement difficulties will be particularly severe, the more stable the suspension, since it will be quite difficult to mechanically... 

Inductively Coupled Plasma. Mass Spectrometry Archaeological Applications. Microscopy Techniques Scanning Electron Microscopy. Surface Analysis X-Ray Photoelectron Spectroscopy Particle-Induced X-Ray Emission Auger Electron Spectroscopy. X-Ray Absorption and Diffraction X-Ray Diffraction - Powder. X-Ray Fluorescence and Emission X-Ray Fluorescence Theory. 

Clinical. Liquid Chromatography Clinical Applications Pharmaceutical Applications. Microscopy Overview. Pharmaceutical Analysis Overview. Sensors Overview. 

Applications Food. Immunoassays, Techniques Enzyme Immunoassays. Infrared Spectroscopy Near-Infrared. Lipids Fatty Acids. Liquid Chromatography Food Applications. Microscopy Applications Food. Nitrogen. Nitrosamines. pH. Phosphorus. Proteins Foods. Sampling Theory Practice. Sulfur. Water Determination. X-Ray Absorption and Diffraction X-Ray Absorption. 

See alsa Chemometrics and Statistics Multivariate Classification Techniques. Forensic Sciences Drug Screening in Sport Illicit Drugs Thin-Layer Chromatography. Gas Chromatography Overview Mass Spectrometry Forensic Applications. Liquid Chromatography Clinical Applications. Microscopy Applications Forensic. Spot Tests. 

A first example of application of microtomography is taken from life sciences. Here X-ray microscopy and microtomography allows to reconstruct the internal three-dimensional microstructure without any preparation and sometimes even of living objects. Fig. la shows an X-ray transmission microscopical image of bone (femoral head). Several reconstructed cross-sections are shown in Fig.lb. Fig.lc shows the three-dimensional reconstruction of this bone. 

A newer and perhaps more useful application of ellipsometry to Langmuir films is their lateral characterization via ellipsometric microscopy [146], A simple modification of the nuU ellipsometer allows one to image features down to 10-/im resolution. Working with a fixed polarizer and analyzer, some domains are at extinction while others are not and appear bright. This approach requires no fluorescent label and can be applied to systems on reflective supports. 

Transmission electron microscopy (TEM) can resolve features down to about 1 nm and allows the use of electron diffraction to characterize the structure. Since electrons must pass through the sample however, the technique is limited to thin films. One cryoelectron microscopic study of fatty-acid Langmuir films on vitrified water [13] showed faceted crystals. The application of TEM to Langmuir-Blodgett films is discussed in Chapter XV. 

Since scanning tunneling microscopy requires flat conducting surfaces, it is not surprising that most of its early application was to study inorganic materials [17, 19, 20, 29-34]. These studies include investigations of catalytic metal surfaces [24, 35-37], silicon and other oxides [21], superconductors [38], gold... 

P. R. Thornton, Scanning Electron Microscopy, Chapman and Hall, 1968. See also Scanning Electron Microscopy Systems and Applications, The Institute of Physics, London, 1973. 

One of the more recent advances in XPS is the development of photoelectron microscopy [ ]. By either focusing the incident x-ray beam, or by using electrostatic lenses to image a small spot on the sample, spatially-resolved XPS has become feasible. The limits to the spatial resolution are currently of the order of 1 pm, but are expected to improve. This teclmique has many teclmological applications. For example, the chemical makeup of micromechanical and microelectronic devices can be monitored on the scale of the device dimensions. 

Turrell G and Corset J (eds) 1996 Raman Microscopy Developments and Applications (New York Academic)... 

Biumioh B and Kuhn W (eds) 1992 Magnetic Resonance Microscopy Methods and Applications in Materials Science, Agriouiture and Biomedioine (Weinheim Wiiey-VCFI)... 

Schrader M, Bahimann K and Hell S W 1997 Three-photon-excitation microscopy Theory, experiment, and applications Optik 104 116-24... 

V Amelinck S, van Dyck D, van Landuyt J and van Trendelo G (eds) 1996 Handbook of Microscopy, Application In Materials Science, Solid State Physics and Chemistry 3 vols (Weinheim VCH)... 

Booker Gr, Laczik Z and Toeroek P 1995 Applications of Scanning Infra-red Microscopy to Bulk Semiconductors (Inst. Phys. Conf Ser., 146) pp 681-92... 

Bard A J and Fan F F 1993 Applications in electrochemistry Scanning Tunneiiing Microscopy and Spectroscopy ed D A Bonnell (Weinheim VCFI) oh 9... 

Flansma P K, Elings V B, Marti O and Bracker C E 1988 Scanning tunnelling microscopy and atomic force microscopy application to biology and technology Science 242 209... 

Rugar D, Mamin FI J, Guenther P, Lambert S E, Stern J E, McFadyen I and Yogi T 1990 Magnetic force microscopy general principles and application to longitudinal recording media J. Appl. Phys. 68 1169... 

Annis B K, Noid D W, Sumpter B G, Reffner J R and Wunderlich B 1992 Application of atomic force microscopy (AFM) to a block copolymer and an extended chain polyethylene Makromol. Chem., Rapid. Commun. 13 169 Annis B K, Schwark D W, Reffner J R, Thomas E L and Wunderlich B 1992 Determination of surface morphology of diblock copolymers of styrene and butadiene by atomic force microscopy Makromol. Chem. 193 2589... 

Lai R and John S A 1994 Biological applications of atomic-force microscopy Am. J. Physiol. 266 Cl... 

For bulk structural detemiination (see chapter B 1.9). the main teclmique used has been x-ray diffraction (XRD). Several other teclmiques are also available for more specialized applications, including electron diffraction (ED) for thin film structures and gas-phase molecules neutron diffraction (ND) and nuclear magnetic resonance (NMR) for magnetic studies (see chapter B1.12 and chapter B1.13) x-ray absorption fine structure (XAFS) for local structures in small or unstable samples and other spectroscopies to examine local structures in molecules. Electron microscopy also plays an important role, primarily tlirough unaging (see chapter B1.17). 

Fulian Q, Fisher A C and Denuault G 1999 Applications of the boundary element method in electrochemistry scanning electrochemical microscopy, part 2 J. Phys. Chem. B 103 4393... 

Gewirth A A and Niece B K 1997 Electrochemical applications of in situ scanning probe microscopy Chem. Rev. 971129... 

Sekatskii S K and Ketokhov V S 1996 Single fluorescence centres on the tips of crystal needles first observation and prospects for application in scanning one-atom fluorescence microscopy Appl. Phys. B 63 525-30... 

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