Light microscopy quantitative

Plant-fiber identification is described in TAPPI T8 and TIO. In order to identify synthetic fibers, it usually is necessary to conduct solubihty and physical properties tests in addition to light microscopy observations. Systematic sampling is required to obtain quantitative information on sample composition. Because different types of pulps contain varying numbers of fibers per unit weight, it is necessary to multiply the total number of each kind of fiber by a relative weight factor, thereby the weight percentage that each fiber type contributes to the sample can be deterrnined. 

With a resolution of 0.01 qm this technique outperforms optical light microscopy (0.1 pm) and is used, e.g., to examine fine particles such as metal fume. When linked to other facilities such as dispersive X-ray analysis, quantitative data can be obtained. 

In this Chapter we will concentrate on the methods of food microscopy rather than the details of results of individual investigations. The reader is referred to Holcomb and Kalab [17], Holcomb [18], and Kalab [19], for an introduction to the details of the microscopical literature of Food Science. We begin with a discussion of some of the more common microscopical techniques in use in Food Science, especially their more uncommon applications. These are rarely published and they are usually confined to industrial applications. Included is a section on quantitative light microscopy. Finally we deal with some of the newer technologies which have yet to be applied widely to food. 

The methods that have proved effective for quantitative determination of phases in clinkers are based on light microscopy (Section 4.2.1), X-ray diffraction (Section 4.3.2) and calculation from the bulk chemical analysis. The last two of these are applicable also to cements. SEM with image analysis (Section 4.3.1) shows promise, but other methods that have been investigated, such as IR spectroscopy, appear to have little potential. Sections 4.4.2 to 4.4.5 describe a method of calculation from the bulk analysis and Section 4.4.6 compares the results of the various methods. 

Different light microscopy techniques, such as autoradiography and quantitative fluorescence microscopy (QFM), have been used to examine the influence of penetration enhancers on percutaneous absorption. 

Masters BR, Kino GS. Charge coupled devices for quantitative Nipkow Disk real-time scanning confocal microscopy. In Shotton D, ed. Electron light microscopy The principles and practice of video-enhanced contrast, digital intensified fluorescence, and confocal scanning light microscopy. New York Wiley-Liss, 1993. 

The distribution of enzyme in carriers is also critical to understanding catalyst activity. Jeroen van Roon, et al. quantitatively determined intraparticle enzyme distribution of Assemblase using light microscopy. They reported the enzyme was distributed heterogeneously and its concentration was radius-dependent. Our laboratory reported the use of infrared microspectroscopy for... 

The basis for rate cements to individual kinds is cement composition based principally on chemical determinations, to which belong insoluble residue and loss on ignition. They are principally linked with cement additions. For quantitative slag content determination from long time the light microscopy is used, and the accuracy of this method is assessed to be 5 % (Fig. 1.6). Lastly also the methods of separation in heavy liquids are recommended, based on the density differences of individual cement components clinker about 3.1 g/cm, slag 2.85 g/... 

Cariou, B. Ranc, R. and Sorrentino, F., "Industrial Application of Quantitative Study of Portland Cement Clinker Through Reflected Light Microscopy," Proceedings of the 10th International Conference on Cement Microscopy, International Cement Microscopy Association,SanAntonio,Texas, 1988, pp. 277-284. 

LM light microscopy Qual = qualitative Quant = quantitative. Not always possible (1,5,10,26). 

Light microscopy (LM) is regularly used to obtain rapid, inexpensive qualitative and quantitative information in food analysis. The first routine use of LM in food analysis was for the identification of adulteration (e.g., the presence of chicory root in coffee) or contamination (insect, rodent, microbial, and foreign bodies). Bright-field, polarizing, and fluorescent microscopy are the three traditional LM techniques used most frequently in food analysis. The basic instrument is a conventional compound (bright-field) microscope, to which polarizing and fluorescence accessories are easily attached. 

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