Reasons for determination

There are two main reasons for determining biogenic amines in foods (1) their potential toxicity and (2) the possibility to use them as food quality markers (quality control of raw materials, monitoring fermentation processes, process control, etc.) [281]. 

Table 11 Reason for Determination of Cereal Proteins in Foods and Food Products...

The reasons for determining the alcohol content of foods and beverages are many. A brief examination was carried out by Amelio (1), large parts of which are reexamined here. 

The measure of mass is important with respect to calculating mass balance. However, the elemental composition of biomass is normally ill defined. Another reason for determining biomass is the need for a reference when calculating specific rates (q ) q = r /x. An ideal measure for the biocatalysts in a bioreaction system of interest would be their activity, physiological state, morphology or other classification rather than just their mass. Unfortunately, these are even more difficult to quantify objectively and this is obviously why the biomass concentration is still of the greatest interest. 

It is essential to document all outstanding issues and include a plan to resolve these, no matter how small. This plan should include the name of an accountable person responsible for the action item and the estimated completion date. In the system acceptance report, specific reasons for determining that the system is validated should be stated this statement should take into account outstanding issues. Many minor issues can render a system invalidated ( death by a thousand cuts ). 

The reason for determining overall migration is that the food contact material may bring about an unacceptable change in the composition of the food (Article 3 of the framework Regulation (EC) 1935/2004). The methods of determining the overall migration into the aqueous simulants (A, B and C) are as follows ... 

Tritium occurs most commonly in water as water itself (HTO). Except for radiological monitoring purposes, the main reason for determining tritium in water is to assess whether the supply is being replenished by rainfall or not. As mentioned earlier, tritiated organic compounds, usually insoluble, are used commercially mainly in luminous equipment or in medicine and research. Such material may eventually end up in tip leachates, effluents and incinerator gases. 

Another reason for determining the potency of different ecotoxicants is to establish structure-activity relationships. In ecotoxicology, these can be used to predict the toxicity of new compounds that share the molecular or physiochemical properties of chemical classes for which structure-activity relationships have been established. The relationships could be derived with fish but can be done more quickly and at less cost with cells. As a result, fish cell lines have been used to develop structure-cytotoxicity relationships for several chemical categories184. The cytotoxicity of lipophilic chemicals was predicted by their octanol/water coefficient184 176. The cytotoxicity of metals was predicted by chemical hardness184. 

A significant reason for determining accurate anharmonic force fields for benzene is that they serve as input into dynamical studies of overtone spectra and intramolecular energy transfer. In previous studies, we have used the force fields developed by Pulay et... 

However, there is a very usefiil reason for determining the type of luminescence decay curve present. Confirming the presence of an exponential decay curve means that only one type of emitter is jn sent. If a logarithmic decay process is found, it usually means that more than one type of emitting center is present, or that two or more decay processes are operative. While this does not occur very often, it is useful to know if such is present. This phenomenon occurs more in cathode-ray phosphors than in lamp phosphors, i.e.- sulfides vs oxide- hosts. 

Which of the following are important reasons for determining the amino acid sequences of proteins ... 

We need to know how effectively cell membranes discriminate between various solutes—is ether, or is a more polar solvent such as ijobutanol, or perhaps the less polar decane, a better model A second reason for determining the solvent characteristics of the permeability barrier is that this approach will help us to identify, the region of the cell membrane which indeed forms the major permeability barrier. Is it the cell membrane interior region, or is it a region close to the membrane surface We will return to this point in following sections of this chapter. 

Among the optical analysis methods, near-infrared (NIR) spectroscopy is the most popular method because of its non-destructive nature, the low operating cost and the fast response times (Armenia et al., 2007), and it also has been successfully applied to quality control in food (Pi et al., 2009 Leroy et al., 2003 Subbiah et al., 2008), petrochemical, pharmaceutical, clinical and biomedical and environmental sectors (Ripoll et al., 2008). Near-infrared (0.7-2.5pm 12900-4000cm-i) spectroscopy is further classified into NIR reflectance spectroscopy and NIR transmission spectroscopy. NIR can be non-dispersive (filter-based instrumentation), dispersive and use Fourier transform-based instrumentation. Table 1 lists some NIR spectroscopic applications suitable for pesticides determination. All these researches have shown the possibility and reasonability for determination of pesticide concentration using NIR spectroscopy. 

The main reason for determining a specific constituent like calcite, organic carbon, and pyrite or a selective bounding form of elements is the necessity to perform selective extractions. Solid-phase extraction of (in)organic compounds continues to be the leading technology for the exhaustive extraction of selective compounds from soil samples. 

Another important reason for determining amino acid sequences is that they provide a chemical tool for studying our evolutionary history. Proteins resemble one another in amino acid sequence if they have a common evolutionary ancestry. Let s look at a specific example. 

For instability appearance analysis it is essential not only to develop the main equations of transfer but to formulate boundary conditions, because dissipative structures appear more frequently near phase boundaries and may be caused by fluctuations of boundary conditions. It is of great practical interest to investigate the role of capillary [5] and electrosurface [6] forces in inducing the instability of mobile phase boundaries. That is the reason for determining boundary conditions for the transfer equation system characterizing the interface of two mobile media (liquid-gas or liquid-liquid). Let be the radius-vector drawn from any fixed space point to another on the phase boundary and n a unit vector normal to the interface and directed towards the interior of phase 1 (the second phase would be written as phase 2). The tangential unit vector at the interfacial surface would be t. Then conjugation conditions for velocities, temperatures, concentrations and electric fields at the interface would be ... 

For other radionuclides which are at least temporarily concentrated in particular organs or tissues of the body, monitoring of specific sites is recommended. Examples are radioiodine, which is taken up by the thyroid, and inhaled radioactive particles which are retained in the lungs. Localized monitoring is also recommended when intake is through a wound, or when there are other reasons for determining the distribution of the radionuclide(s) within the body. 

This section describes several reasons for determining colouring agents in cosmetic products. The determinations have regulatory, forensic, or manufacturing significance as presented below. 

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