Analysis of Moisture

These technical aspects show that the moisture content is an important measure that must be assessed carefully. One should be aware that the moisture content of a coal consists usually of three parts  

1) Surfece moisture is water adhering to the surfece of the coal and is also called free moisture. 

2) Inherent or hygroscopic moisture is equivalent to bed, equilibrium, or capacity moisture and is assumed to be the water held in the pores and capillaries of the coal. 

3) Physically and chemically bonded water is not easy to determine and refers mainly to water of hydration of mineral matter, which is usually approximately 8wt% of the ash varying between 2 and 20wt% further details are discussed in Section 3.11.3. 

The proximate moisture will determine the water residing within the coal matrix comprising all forms except crystallization water of the mineral matter. Because of the discrimination between surface and inherent moisture, which add up to the total moisture, two-stage methods are applied to determine as-received and air-dried moisture. 

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Table 3 Wm Values for Various Starches Obtained from BET Analysis of Moisture Uptake Isotherms...

Papaveraceae, alkaloids in, 2 75 Papaverine, 2 87-88 from vanillin, 25 554 Paper, 18 89-132. See also Papermaking analysis of moisture and fluid resistance for, 18 101... 

MEK/sec.-butyl alcohol (25/75) primarily used for the analysis of moisture, ethyl alcohol, and diethyl ether in single-base propellants containing nitrocellulose of approximately 13.15% nitrogen. 

Jankovic, D., Kiintz, M. and Van Mier, J.G.M. (2001) Numerical Analysis of Moisture Flow and Concrete Cracking by means of Lattice Type Models. Proceedings of FraMCoS-4, Cachan, France 1, 231-238. 

FIGURE 5.18 PCR (o), PLS ( ), and simplex () harmonious plots for NIR analysis of moisture in soy samples. The PCR and PLS 1 factor models are in the lower right comer, and the respective models are 8 and 7 factors in the upper left comer. The simplex models converged to RR and GRR models. The RMSEC values are with n — 1 degrees of freedom. 

York, P. Analysis of moisture sorption hysteresis in hard gelatin capsules, maize starch, and maize starch drug powder mixtures. J. Pharm. Sci. 1981, 33, 269-273. 

Table 3 BA values for various starches obtained from BET analysis of moisture uptake isotherms...

Eckert E. and Faghri M. (1980) A general analysis of moisture migration caused by temperature difference in an unsaturated porous medium, Int. J. Heat Mass Transfer, vol. 23, pp.1613-1623. Int. J. Heat Mass Transfer, 23, 1613-1623, 1980. 

Stewart, J.L. Analysis of moisture content of whole cigarettes by nondestructive nuclear magnetic resonance R DM, 1983, No. 23, June 6, see www.rjrtdocs.com 509525381 -5382. 

Ormarsson, S., 1999. Numerical analysis of moisture- related distortions in sawn timber, PhD thesis, Chalmers University of Technology, Gdteboig, Sweden. 

The Association of Official Analytical Chemists (AOAC) publishes reference methods for the analysis of moisture in foods. Some of these methods are summarized in Table 3. 

Microwave analysis of moisture is also known as LOD (loss on drying), drying test, or total volatile solids. For many years, the standard oven test was used for moisture determination. Although very accurate, the test could take many hours to complete, depending on the sample. The time lapse rendered it practically useless for anything except a final quality control check. The new microwave moisture/solids analyzers were introduced about 20 years ago. They offer rapid, accurate moisture/solids analysis in a fraction of the time it took to run a standard oven-drying test. 

Roels S, Carmehet J Analysis of moisture flow in porous materiab using microfocus X-ray radiography, Int J Heat Mass Transf49(25—26) 4762-4772, 2006. 

F. E. L. Tobing, M. S. Shephard, and S. S. Stemstein, Finite element analysis of moisture effects in graphite-epoxy composites, Comput. Struct. 16, 457-469 (1983). 

NIR analysis of liquids has the longest history of all sampling types simple two-filter, two-wavelength instruments have been used for decades, mainly for the analysis of moisture in various liquid media. The sample presentation of liquids seems to be much simpler than that of solids, but there are several factors influencing the accuracy and precision of the analysis that need to be addressed for a successful liquid analysis. 

Choice of the type of measurement to be used for control depends on the process. Under isothermal conditions, the moisture content of solid materials varies with relative humidity, but in adiabatic processes, a determining factor is wet-bulb temperature. An exact analysis of moisture content can best be found by an absolute-humidity measurement, however. 

Non-destructive and rapid analysis of moisture distribution in farmed Atlantic salmon (Salmo salar) fillets using visible and near-infrared hyperspectral imaging. Innovative Food Sci. Emerg. TechnoL, 18, 237—245. 

The efficiency of the various milling procedures is usually determined by the analysis of moisture, ash, fat, and color of refined products. The most common way to determine milling efficiency is by the quantification of ash (AACC Methods 08-03 and 08-12), because the degree of refining is inversely related to the mineral content. This is because bran contains 20 times more ash than the endosperm. Ash is determined gravimetrically after burning or incinerating a sample at temperatures of 600°C. There are other less accurate methods that can predict ash content. The most popular used today is the NIRA. 

TGA has also been used in the analysis of moisture and ash content of flours, and the moisture content of pasta, coffee and powdered milk. 

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