Quantitative for the

Susceptibility to radiation damage must be considered seriously if reference samples are to be calibrated for use in place of absolute systems. For the measurement of absolute C He, H) cross sections, films of polystyrene (CH) (which is relatively radiation hard) have been used successfiiUy, the RBS determination of carbon providing implied quantitation for the hydrogen present in the film. For a durable laboratory reference sample, however, there is much to recommend a known ion-implanted dose of H deep within Si or SiC, where the loss of hydrogen under room temperature irradiation will be neghgible. 

ITie BET method is the most widely used procedure for determining the surface area of porous materials. In this chapter, BET results were obtained from single point measurements using a Micromeritics Flowsorb II 2300 surface area analyzer. A mixture of nitrogen in helium (30 70 mole percentage) was used. Although this simple method is not quantitative for the microporous materials studied in section 5, it still allows qualitative comparisons to be made. 

The constant 607 is a combination of natural constants, including the Faraday constant it is slightly temperature-dependent and the value 607 is for 25 °C. The IlkoviC equation is important because it accounts quantitatively for the many factors which influence the diffusion current in particular, the linear dependence of the diffusion current upon n and C. Thus, with all the other factors remaining constant, the diffusion current is directly proportional to the concentration of the electro-active material — this is of great importance in quantitative polarographic analysis. 

The last point has been studied more quantitatively for the electrolyte LiOjCCH Fy (x+y=3) / DMSO [97,105], Semiempirical quantum-mechanical calculations with the help of MOP AC [143] show that the mean electron density at the oxygen atoms q(0) decreases for these acetates by about 0.1 unit with increasing fluorine content of the anion [97]. As a consequence ... 

The overall process shown as reaction (14) is a necessary consequence of the observed CH3D/CH4 ratio. To be consistent with a ratio of unity, this reaction must proceed without the liberation of free methyl radicals and must account quantitatively for the fate of the methyl zinc. The exact nature of reaction (14) is unknown but several important observations have been made. Decomposition of Zn(CD3)2 with C6H12 in a vessel conditioned using Zn(CH3)2 produced the expected yield of CD4 indicating that the additional hydrogen needed for reaction (14) does not come from the coating on the conditioned vessel. Since reaction (15) cannot compete successfully under the experimental conditions used, it is doubtful if the reaction... 

It may be possible to evaluate the percent extracted by a separate experiment. A solution of the analyte in the original solvent may be prepared such that WOTig (before extraction) is known. Following this, an extraction is performed on this solution using a particular volume of extracting solvent (V ). This volume of extract is then analyzed quantitatively for the analyte by some appropriate analysis technique. Knowing the concentration of the analyte and the volume of extract converted to liters (L ), one can calculate the percent extracted ... 

An attempt is made to account quantitatively for the volumes of activation, AV, of ligand substitution processes. Causes of the pressure-dependence of AV include solvational change, for which a versatile analysis is developed. The pressure-independent AV values of solvent exchange reactions are good measures of the non-sol-vational components of AV for related net reactions. For water exchange, one can predict... 

Ach on carbon orbital hybridization in hydrocarbons is not found to hold quantitatively for the boron hydrides. 

Finally, a striking property of metal-ammonia solutions is the large expansion of the liquid due to the solvated electrons. The apparent volume of the solvated electron remains roughly constant up to the metallic range, then shows a slight increase. It is about 100 cm3 mol. It is this effect that has led to the hypothesis that the electron forms a cavity for itself a cavity of radius 3.2 A accounts quantitatively for the excess volume. A model in which the electron moves in a cavity, and the surrounding liquid is polarized or solvated as it is round a cation, was first put forward by Jortner (1959), who showed that it was able to account for the absorption spectrum. Jortner s model, as modified by Mott (1967), Cohen and Thompson (1968) and Catterall and Mott (1969), will now be described. 

These authors were the first FGSE workers to make extensive use of the concept of free volume 42,44) and its effect on transport in polymer systems. That theory asserts that amorphous materials (liquids, polymers) above their glass transition temperature T contain unoccupied volume randomly distributed and in parcels of sufficient size to permit jumps of small molecules — and of polymer jumping segments — to take place. Since liquids have a fractional free volume fdil typically greater than that, f, of polymers, the diffusion rate both of diluent molecules and (uncrosslinked and unentangled) polymer molecules should increase with increasing diluent volume fraction vdi,. The Fujita-Doolittle expression 43) describes this effect quantitatively for the diluent diffusion ... 

To summarize, we have shown that the ideal Donnan model cannot account quantitatively for the ionic effects on gel swelling. Nevertheless, using the heuristic procedure introduced above, the Donnan theory can be used to predict qualitative trends. 

As soon as the current is turned on, lead chromate begins to roll off the anode and fall to the bottom of the cell. Very little adheres to the anode plate. After about 2 hr., shut off the current and allow the suspended particles to settle. Decant the clear liquid, wash the precipitate with hot water by a second decantation, collect the solid on a filter, and dry it in the air oven. The yield should be very nearly quantitative for the current used. 

Throughout this discussion, we have ignored consideration of the behavior of the surface potentials. In general, the surface dipole moments have provided qualitative support for the findings obtained from molecular area data. At this stage, however, we are not able to account quantitatively for the surface dipole moments. 

When small corrections are made to allow for the direct reaction of aniline with the ester, it can be shown that a quantitative yield of acetanilide is produced, so that nucleophilic catalysis accounts quantitatively for the observed reaction. 

The analytical data on monocarbonyls, olefins, and oxides of carbon were then used to strike a carbon balance for the purpose of finding what part of the cool-flame combustion products had been accounted for. The balance for n-hexane proved to be nearly quantitative. For the more highly branched isohexanes the carbon balance was much less complete. 

The He2A 2 state has nearly the same dissociation energy as the He (22J ion. This supports the idea that the excited He2 configurations can be described at small interatomic distances as an inner He core with an outer Rydberg orbital. This description is less quantitative for the heavier rare-gas pairs. The unusual maxima result either from curve crossing (e.g., C S ) or as for the state by a changeover in the... 

WWe have seen that sedimentation by centrifugation is used for protein purification. The methods of centrifugation can be used quantitatively for the assessment of protein size and shape. 

In order to account quantitatively for the rate data over the entire extent of reaction, it is necessary to consider the fact that sodium ethoxide is only slightly soluble in ammonia, and that its solubility is markedly increased by the addition of ethanol. It happens that, in accounting for the kinetics, the following arbitrarily chosen equilibrium is satisfactory. 

Leuthold, L. A., Grivet, C., Allen, M., Baumert, M., and Hopfgartner, G. (2004). Simultaneous selected reaction monitoring, MS /MS and MS3 quantitation for the analysis of pharmaceutical compounds in human plasma using chip-based infusion. Rapid Commun. Mass Spectrom. 18 1995-2000. 

To account quantitatively for the preceding effects, Sun et al. (1995) developed a model to simulate the influence of a surfactant on the magnitude of the sorption of a hydrophobic organic contaminant. The governing equation is given by... 

Chapter 4.4 addressed various aspects of qualitative identification of pollutants with common analytical techniques, such as chromatography and elemental analysis. Another integral component of environmental analysis is pollutant quantitation. For the data to be valid and usable, the analytes must be not only correctly identified but also properly quantified. 

Increased concentration of analytes in the acceptor matrix to levels over the limit of quantitation for the chosen analytical technique. 

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