Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Quantitative applications using

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

Table 2 Possible Quantitative Applications Using MALDI-TOF MS... Table 2 Possible Quantitative Applications Using MALDI-TOF MS...
Quantitative applications using multiple isotopic archives... [Pg.395]

This approach will not be practical for some time to come. The fundamental properties of surfactants (micelle formation, enrichment at interfaces) mean that the activity of a surfactant will usually differ from its absolute concentration (1). Just as serious is the technical problem that current surfactant-selective electrodes suffer from response which varies with their past and recent history they are also sensitive to the concentration of nonsurfactant ions. The result is that quantitative applications use electrodes not in direct measurements relating potential to concentration, but as indicators of the end point of a titration. In this latter application, it is not important that the electrode potential be exactly reproducible, but only that the potential change sharply as the surfactant concentration changes. For the titration of an anionic surfactant with a cationic surfactant, the electrode used for end point detection can be chosen to respond to either surfactant. Because of the drift in electrode potential, titrations must be conducted to an inflection in the titration curve rather than to a specific millivolt value. Details of the potentiometric titration methods can be found earlier in this chapter. The electrodes have also been demonstrated as detectors for flow injection analysis. [Pg.513]

One of the earliest NDT applications for laser-based profilometry systems was for the inspection of marine boiler tubes. Under funding from the U.S. Navy", several systems were developed that were capable of rapidly and accurately mapping the inside surface of 25 mm and 50 mm diameter boiler tubing. Features such as internal pitting and corrosion can be located and quantitatively assessed using computer-graphic analysis. The system employs an... [Pg.1063]

The focus of this section is the emission of ultraviolet and visible radiation following thermal or electrical excitation of atoms. Atomic emission spectroscopy has a long history. Qualitative applications based on the color of flames were used in the smelting of ores as early as 1550 and were more fully developed around 1830 with the observation of atomic spectra generated by flame emission and spark emission.Quantitative applications based on the atomic emission from electrical sparks were developed by Norman Lockyer (1836-1920) in the early 1870s, and quantitative applications based on flame emission were pioneered by IT. G. Lunde-gardh in 1930. Atomic emission based on emission from a plasma was introduced in 1964. [Pg.434]

Chemical kinetic methods of analysis continue to find use for the analysis of a variety of analytes, most notably in clinical laboratories, where automated methods aid in handling a large volume of samples. In this section several general quantitative applications are considered. [Pg.636]

Three common quantitative applications of radiochemical methods of analysis are considered in this section the direct analysis of radioactive isotopes by measuring their rate of disintegration, neutron activation, and the use of radioactive isotopes as tracers in isotope dilution. [Pg.644]

The results for the tunneling splitting calculated with the use of some of the earlier proposed reaction paths for a single PES (4.40) (with the parameters adopted here) are collected by Bosch et al. [1990]. All of them underestimate by at least an order of magnitude the numerically exact value 10.6 cm which is also given in that paper. The parameters C and Q hit the intermediate region between the sudden and adiabatic approximations, described in sections 2.5 and 4.2, and neither of these approximations is quantitatively applicable to the problem. [Pg.99]

Cyclic voltammetry can also be useful for quantitative purposes, based on measurements of the peak current (equation 2-1). Such quantitative applications require the establishment of the proper baseline. For neighboring peaks (of a mixture), the baseline for the second peak is obtained by extrapolating the current decay of the... [Pg.39]

The problems involved in quantitative analysis using NMR spectroscopy, have been discussed by several authors and it is evident that it still causes a lot of problems as especially pointed out by Hays55 in his excellent review on the subject. Thus in liquid state NMR spectroscopy the quantitative estimation of atoms and groups involves the use of normal analytical method. In the case of solid state NMR spectroscopy, however, the application of the cross-polarization technique results in signal enhancements and allows repetition rates faster than those allowed by the carbon C-13 Tl. Therefore, the distortion of relative spectral intensities must always be considered a possibility, and hence quantitative spectra will not always be obtained. [Pg.19]

Optional mathematical derivations. The How do we do that feature sets off derivations of key equations and encourages students to appreciate the power of mathematics by showing how it enables them to make progress and answer questions. All quantitative applications of calculus in the text are confined to this feature. The end-of-chapter exercises that make use of calculus are identified with a [cl... [Pg.16]

The instrument scan mode called selected reaction monitoring (SRM) is generally used for quantitative applications. SRM is similar to selected ion monitoring (SIM) in single quadrupole MS. The difference is that a product ion from the decomposition reaction in the collision cell is measured instead of a single ion formed in the... [Pg.831]

We begin by reviewing the principles of SECM methods, and present an overview of the instrumentation needed for experimental studies. A major factor in the success of SECM, in quantitative applications, has been the parallel development of theoretical models for mass transport. A detailed treatment of the theory for the most common SECM modes that have been used to study liquid interfaces is therefore given, along with key results from these models. A comprehensive assessment of the applications of SECM is provided and the prospects for the future developments of the methodology are highlighted. [Pg.290]

Another parameter essential for quantitative applications of micropipettes is the internal ohmic resistance, R. It is largely determined by the solution resistance inside the narrow shaft of the pipette, and can be minimized by producing short (patch-type) pipettes. The micropipette resistance has been evaluated from AC impedance measurements. Beattie et al. measured the resistance of micropipettes filled with aqueous KCl solutions (0.01, 0.1, and 1 M) [18b]. The value obtained for a 3.5/am-radius pipette was within the range from 10 to 10 As expected, the tip resistance was inversely proportional to the concentration of KCl in the filling solution. In ref. 18b, the effect of pipette radius on the tip resistance was evaluated using a constant concentration of KCl. The pipette resistance varied inversely with the tip radius. The iR drop was found to be 4.5-8 mV for the pipette radii of 0.6 to 19/rm when 10 mM KCl was used. [Pg.388]

The quantitative application of the law of mass action to electrolytes in solution is somewhat limited in scope. However, the law proves to be useful in the elucidation of many of the phenomena connected with precipitation, and the behavior of mixed electrolytes. [Pg.603]

Dry column chromatography [528] provides several improvements over traditional column chromatography, such as better resolution and high speed. Another important characteristic is the near-quantitative applicability of TLC results in dry column analysis. Knowledge of the TLC characteristics of a sample is useful before column chromatography is employed. Careful control of the moisture content of the adsorbent is crucial to the dry column as well as other types of chromatography. [Pg.231]


See other pages where Quantitative applications using is mentioned: [Pg.429]    [Pg.270]    [Pg.38]    [Pg.429]    [Pg.270]    [Pg.38]    [Pg.713]    [Pg.94]    [Pg.261]    [Pg.424]    [Pg.441]    [Pg.129]    [Pg.94]    [Pg.62]    [Pg.170]    [Pg.34]    [Pg.191]    [Pg.205]    [Pg.137]    [Pg.91]    [Pg.418]   
See also in sourсe #XX -- [ Pg.485 , Pg.486 , Pg.487 , Pg.488 , Pg.489 , Pg.490 , Pg.491 , Pg.492 , Pg.493 , Pg.501 , Pg.502 , Pg.586 , Pg.587 ]




SEARCH



Applications quantitative

Atomic emission spectroscopy quantitative applications using

Molecular quantitative applications using

Precision quantitative applications using

Quantitative Applications Using Molecular Luminescence

Quantitative applications using calculations

Quantitative applications using potentiometric titrations

Voltammetry quantitative applications using

© 2024 chempedia.info