Fiber analyses

Fiber Analysis. Paper may be composed of one or several types of fibers, eg, animal, vegetable, mineral, and synthetic (see Eibers). Paper is generally composed of woody vegetable fibers obtained from coniferous (softwood) and deciduous (hardwood) trees. QuaUtative and quantitative methods have been developed to determine the fibrous constituents in a sheet of paper (see TAPPI T401). However, the proliferation in the number and types of pulping processes used have made the analysis of paper a much more complex problem. Comprehensive reviews of the methods are given in References 20 and 23. 

The detergent method for insoluble fiber superseded the cmde fiber method and became the method of choice for insoluble fiber analysis until the 1980s, when methods were developed to recover soluble fiber as well. Some analysts still prefer the NDF procedure for insoluble fiber. The method is simple, inexpensive, reproducible, and amenable to routine assays. The disadvantage is the inabiUty to recover the soluble fraction. See Reference 14 for more information on detergent methods. 

Epidermal nerve fiber analysis by immunocytochemical techniques using the panaxonal marker protein gene product 9.5 (PGP 9.5) allows the study of epidermal innervation by small fiber C and A5 nerve fibers (McCarthy et al. 1995 Holland et al. 1997). Studies of skin biopsies of HIV infected patients with DSP or ATN showed reduction in the number of epidermal fibers in distal areas of the lower extremities with an inverse correlation between neuropathic pain intensity and epidermal nerve fiber density (Polydefkis et al. 2002) (Fig. 4.3). There were also fewer epidermal fibers in HIV seropositive patients without clinical evidence of neuropathy, suggesting that HIV infection may be associated with the loss of cutaneous innervation even before the onset of sensory symptomatology (McCarthy et al. 1995). 

The light intensity of the 3000 A lamps was determined as previously described ( ). Yarn samples were knit on a Lawson Fiber Analysis Knitter (FAK), and yarn tensile testing was performed on an Instron Model 1101 (TM-M) constant rate of extension testing machine. 

Goering, H. K. and Van Soest, P. J. (1970) Forage Fiber Analysis, Agricultural Research Service/United States Department of Agriculture, Washington, DC. 

Saura-Calixto F, Garcia-Alonso A, Goni I and Bravo L. 2000. In vitro determination of the indigestible fraction in foods an alternative to dietary fiber analysis. J Agric Food Chem 48 3342-3347. 

While as a general means of material study the method is universal in its capabilities, it is primarily in the analysis of polymers that it is useful for forensic purposes. The area where it is perhaps most needed and which also demonstrates the methodological approach best is that of fiber analysis. 

Fiber analysis Polymer identification and testing (chemistry)... 

The most sensitive method for CVAA has recently been reported by Wooten et al. (39) using solid-phase microextraction to concentrate the derivatized analyte. Urine, with added ammonium acetate buffer and PhAsO as an internal standard, was derivatized directly with 1,3-propanedithiol and the derivative concentrated on a poly(dimethylsiloxane) (PDMS) solid-phase microextraction (SPME) fiber. Analysis was by automated GC/MS using SIM of the isotopic MH+ ions. An impressive detection limit of 7.4pg/ml was reported, using a benchtop GC/MS system. The method was validated using spiked human urine. 

If the question of fiber composition is recognized by both the manufacturer and the user, the choice of a fiber furnish which has the necessary qualities is achieved by agreement. When the fiber source is unknown to the purchaser, a fiber analysis is a necessary requirement. Procedures for fiber analysis are well standardized and reliable—e.g., TAPPI standard T401 (3) and ASTM D1030 ( 4). 

We thank the staff of the R. H. Lowie Museum of Anthropology for their assistance in providing well-provenanced textiles. Thanks to Dr. Wilfred Ward, USD A Regional Lab, Albany, California, for the confirmatory camelid fiber analysis. Also, many thanks for the help for so long... 

The visual evoked potential recordings in LHON become desynchronized early in the disease. This is accompanied by a prolonged latency and reduction in peak amplitude. In the later stages of the disease, visual evoked potentials may diminish entirely. Nerve fiber analysis shows severe and progressive loss of the NFL. 

Case BW, Sebastien P, McDonald JC. 1988. Lung fiber analysis in accident victims A biological assessment of general environmental exposure. Arch Environ Health 43 178-179. 

Murai Y, Kitagawa M, Hiraoka T. 1997. Fiber analysis in lungs of residents of a Japanese town with endemic pleural plaques. Arch Environ Health 52 263-269. 

Murai Y, Kitagawa M, Matsui K, et al. 1995b. Asbestos fiber analysis in nine lung cancer cases with high asbestos exposure. Arch Environ Health 50 320-325. 

Use Manufacture of chemicals, condensation reactions, catalyst in making acetate fibers. Analysis of minerals, slags, and fluxes determination of arsenic in metals separation of polonium from tellurium fungicide, germicide. 

Details of single fiber analysis have been given by Bresee. Therefore, in this chapter, only highlights of some of the important methods for fiber identification have been considered. 

In many cases, matching fibers from the scene with those from the clothing of a suspect or a victim is the required analysis. In others, the identification of the particular type of fiber is important. In the first instance, microscopy is the usual technique employed in the second, chemical testing is necessary. Recorded police files contain numerous cases on in which the conclusion as to guilt or innocence is based primarily on fiber analysis. This exercise is limited to the identification of textile fibers as to general type by solubility measurements. 

The problems associated with the isolation and analysis of cell walls are (1) those arising from the preparation of cell wall material, (2) those associated with the isolation of wall components, (3) those associated with the fractionation of the carbohydrate polymers. There are also problems associated with the determination of the constituent sugars, their mode of occurrence, and fine structural details these are discussed later. The problems encountered in dietary fiber analysis and lignin determination, and measures for overcoming them, have been discussed at some length in a recent review (Selvendran and Du Pont, 1984) and will not be described in this chapter. 

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