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Quantitative applications involving

The use of ultrasound-assisted slurry is a simple, efficient alternative to circumvent problems associated to digestion of samples with complex matrices derived from the required hazardous conditions, but also to leaching when efficiencies are not quantitative. Applications involving slurries prepared by ultrasonic assistance are continuously proposed with different detection systems, which demonstrate the versatility of slurries for metallic elements determination. [Pg.149]

The Mole Concept and Chemical Compounds—In this section, the concept of atomic mass is extended to molecular mass, the mass in atomic mass units of a molecule of a molecular compound, and formula mass, the mass in atomic mass units of a formula unit of an ionic compound. Likewise, the concept of the Avogadro constant and the mole is now applied to compounds, with emphasis on quantitative applications involving the mass of a mole of compound— the molar mass M. For several elements, we can distinguish between a mole of molecules (for example, P4) and a mole of atoms (that is, P). [Pg.100]

Analytical chemistry is often described as the area of chemistry responsible for characterizing the composition of matter, both qualitatively (what is present) and quantitatively (how much is present). This description is misleading. After all, almost all chemists routinely make qualitative or quantitative measurements. The argument has been made that analytical chemistry is not a separate branch of chemistry, but simply the application of chemical knowledge. In fact, you probably have performed quantitative and qualitative analyses in other chemistry courses. For example, many introductory courses in chemistry include qualitative schemes for identifying inorganic ions and quantitative analyses involving titrations. [Pg.2]

Perhaps the most useful application of ISS stems from its ability to monitor very precisely the concentration and thickness of contaminants on metals during development of optimum processing and cleaning operations. One particularly important application involves quantitatively monitoring total carbon on cleaned steels before paint coating. This has been usefid in helping to develop optimum bond... [Pg.523]

The eigenvalue problem was introduced in Section 7.3, where its importance in quantum mechanics was stressed. It arises also in many classical applications involving coupled oscillators. The matrix treatment of the vibrations of polyatomic molecules provides the quantitative basis for the interpretation of their infrared and Raman spectra. This problem will be addressed tridre specifically in Chapter 9. [Pg.88]

Finally, it should be kept in mind that quantification is often problematic in surface analysis and characterization. Firstly because some techniques are not really suited for quantification, but also in cases such as infrared spectroscopy where one does not really know precisely how deep into the material one is probing. Although, there are many good examples of semi-quantitative applications that involve measuring relative band intensities that relate to changes in a surface property. However, for problem solving revealing qualitative differences is often sufficient information to be able to identify cause and move on to look for a potential solution. [Pg.677]

A final observation is in order the quantitative application of the equilibrium thermodynamical formalism to living systems and especially to ecosystems is generally inadequate since they are complex in their organisation, involving many interactions and feedback loops, several hierarchical levels may have to be considered, and the sources and types of energy involved can be multiple. Furthermore, they are out-of-equilibrium open flow systems and need to be maintained in such condition since equilibrium is death. Leaving aside very simple cases, in the present state of the art we are, therefore, limited to general semiquantitative statements or descriptions (e.g. ecosystem narratives ). [Pg.123]

Basic Principles. Egerton (47-50) has given admirable summaries of the background theory and the equations required for quantitative application of EELS to the determination of specimen composition suffice it to note that ionization energies depend upon the type of shell (K, L, etc.) and upon the atomic number (Z) of the atom involved. Their values have been accurately... [Pg.444]

In theory, the wave equations of quantum mechanics can be used to derive near-correct potential-energy curves for molecular vibrations. Unfortunately, the mathematical complexity of these equations precludes quantitative application to all but the very simplest of systems. Qualitatively, the curves must take the anharmonic form. Such curves depart from harmonic behavior by varying degrees, depending on the nature of the bond and the atom involved. However, the harmonic and anharmonic curves are almost identical at low potential energies, which accounts for the success of the approximate methods described. [Pg.371]

The majority of quantitative applications using UV-Vis involve measurement of the standards and samples of comparable concentrations in rapid succession using... [Pg.164]

Two main types of analysis are required (a) qualitative determination of the presence of elements and (b) quantitative determination of the amount of elements or species of interest contained in pharmaceutical products. Most analyses for pharmaceutical applications involve separation steps combined with ICP-MS, such as HPLC-ICP-MS or gel electrophoresis and the analysis of gel blots by LA-ICP-MS. Phosphorylated proteins (e.g., (3-casein) have been measured by LA-ICP-MS with a detection limit of 16pmol. HPLC-ICP-MS has been employed for the identification and quantification of metabolites of bradykinin in human and rat plasma.1... [Pg.457]

Ref J.Mitchell, Jr D.M.Smith, "Aqua-merry/ Application of the Karl Fischer Reagent to Quantitative Analysis Involving Water, Interscience, NY(1948)... [Pg.476]

The phase rule applies to true equilibrium systems, where the equilibrium can be reached from either side, and. furthermore, lakes no accoum of the lime involved to attain equilibrium. The phase rule is a qualitative statement., whereas the law of mass action (concentration effect I is quantitatively applicable to those equilibrium systems where the reaction which occurs may be considered to take place in a homogeneous system, e.g gas phase, or. solution phase. (See also Chemicnl Reaction Rate.). [Pg.349]

It seems to me that the difficulties of rigorous proof of principles from axioms or the intricacies involved in the quantitative application of the principles to chemical problems should not prevent an open-minded person from accepting these principles without understanding the details of their proof nor from searching for qualitative applications of them. [Pg.126]

The calibration methods most frequently used to relate the property to be measured to the analytical signals acquired in NIR spectroscopy are MLR,59 60 principal component regression (PCR)61 and partial least-squares regression (PLSR).61 Most of the earliest quantitative applications of NIR spectroscopy were based on MLR because spectra were then recorded on filter instruments, which afforded measurements at a relatively small number of discrete wavelengths only. However, applications involving PCR and PLSR... [Pg.374]

Quantitation Once protein expression profiling activities characterize qualitative features, the attention turns to delineating protein interactions and mechanistic pathways responsible for disease. These studies also require rapid sequence determination/confirmation combined with accurate and sensitive quantitative analysis. The quantitation approaches would allow for direct comparison of protein amounts (absolute or relative) from a variety of cellular states. Because of the reasons stated previously, quantitative applications are likely to be less dependent on 2-DGE and rely primarily on formats that involve specific purification and/or chromatographic separation with mass spectrometry. [Pg.76]

R. J. Smith, Methods Carbohydr. Chem., 4, 36-41 (1964) K. Fischer, Angew. Chem., 48,394-396 (1935) J. Mitchell and D. M. Smith, Aquametry. Application of the Karl Fischer Reagents to Quantitative Analysis Involving Water, Interscience, New York, 1948. [Pg.221]

Reversible Equilibria. As noted in Table I, there are many reversible equilibria available in alkali metal vapors to accomodate external stresses and perturbations. The liquid t vapor equilibrium is of fundamental importance in connection with heat pipes (1) and also in many applications, e.g. lithium in fusion (25). Equilibria involving clustering (beginning with atom-atom recombination to the diatom (3, 4)) are just beginning to be understood quantitatively. Equilibria involving ionization are of major importance for the readily ionized alkali metal species (18, 19, 38). A final equilibrium which has apparently been much less studied (1) is the "Mott" metal-insulator transition which occurs for all alkali metal vapors at high density (52, 53). [Pg.400]


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Quantitative applications involving calculation

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