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Instrumentation and instrumental methods

Instrumentation and Instrumental Methods of Analysis (see also next topic). The principle purposes of instrumentation in the chemical industry are to measure and control physical changes and chemical reactions. Instrumental methods of analysis concern the application of... [Pg.374]

In this section, we define each of ilic six figures of merit listed in Table 1 3. These ligurcs are then used throughout the remainder of the text in discussing various instruments and instrumental methods. [Pg.19]

Leniart D S 1979 Instrumentation and experimental methods in double resonance Multiple Electron Resonance Spectroscopy ed M M Doric and J H Freed (New York Plenum) ch 2, pp 5-72... [Pg.1588]

Pick s second law of difflision enables predictions of concentration changes of electroactive material close to the electrode surface and solutions, with initial and boundary conditions appropriate to a particular experiment, provide the basis of the theory of instrumental methods such as, for example, potential-step and cyclic voltanunetry. [Pg.1924]

Greet R, Peat R, Peter L M, Pletcher D and Robinson J 1993 Instrumental Methods in Electrochemistry (Chichester Southampton Electrochemistry Group/Ellis Horwood)... [Pg.1949]

Present day techniques for structure determination in carbohydrate chemistry are sub stantially the same as those for any other type of compound The full range of modern instrumental methods including mass spectrometry and infrared and nuclear magnetic resonance spectroscopy is brought to bear on the problem If the unknown substance is crystalline X ray diffraction can provide precise structural information that m the best cases IS equivalent to taking a three dimensional photograph of the molecule... [Pg.1052]

Before the widespread availability of instrumental methods the major approach to structure determination relied on a battery of chemical reactions and tests The response of an unknown substance to various reagents and procedures provided a body of data from which the structure could be deduced Some of these procedures are still used to supple ment the information obtained by instrumental methods To better understand the scope and limitations of these tests a brief survey of the chemical reactions of carbohydrates is m order In many cases these reactions are simply applications of chemistry you have already learned Certain of the transformations however are unique to carbohydrates... [Pg.1052]

Data for the several flame methods assume an acetylene-nitrous oxide flame residing on a 5- or 10-cm slot burner. The sample is nebulized into a spray chamber placed immediately ahead of the burner. Detection limits are quite dependent on instrument and operating variables, particularly the detector, the fuel and oxidant gases, the slit width, and the method used for background correction and data smoothing. [Pg.727]

Time, Cost, and Equipment Acid-base titrations require less time than most gravimetric procedures, but more time than many instrumental methods of analysis, particularly when analyzing many samples. With the availability of instruments for... [Pg.313]

Frequently an analyst must select, from several instruments of different design, the one instrument best suited for a particular analysis. In this section we examine some of the different types of instruments used for molecular absorption spectroscopy, emphasizing their advantages and limitations. Methods of sample introduction are also covered in this section. [Pg.388]

The second factor influencing detection limits is the instrumental method used to monitor the reaction s progress. Most reactions are monitored spectrophotometrically or electro-chemically. The scale of operation for these methods was discussed in Chapters 10 and 11 and, therefore, is not discussed here. [Pg.640]

Most of the experimental information concerning copolymer microstructure has been obtained by physical methods based on modern instrumental methods. Techniques such as ultraviolet (UV), visible, and infrared (IR) spectroscopy, NMR spectroscopy, and mass spectroscopy have all been used to good advantage in this type of research. Advances in instrumentation and computer interfacing combine to make these physical methods particularly suitable to answer the question we pose With what frequency do particular sequences of repeat units occur in a copolymer. [Pg.460]

The quahty of an analytical result also depends on the vaUdity of the sample utilized and the method chosen for data analysis. There are articles describiag Sampling and automated sample preparation (see Automated instrumentation) as well as articles emphasizing data treatment (see Chemometrics Computer technology), data iaterpretation (see Databases Imaging technology), and the communication of data within the laboratory or process system (see Expert systems Laboratory information managet nt systems). [Pg.393]

Instrumental Methods. A variety of spectroscopic techniques are available for the characterization of siUcones. Descriptions of these techniques and Hterature references relevant to siUcone analysis are summarized in Table 12. [Pg.59]

Instrumental Methods for Bulk Samples. With bulk fiber samples, or samples of materials containing significant amounts of asbestos fibers, a number of other instmmental analytical methods can be used for the identification of asbestos fibers. In principle, any instmmental method that enables the elemental characterization of minerals can be used to identify a particular type of asbestos fiber. Among such methods, x-ray fluorescence (xrf) and x-ray photo-electron spectroscopy (xps) offer convenient identification methods, usually from the ratio of the various metal cations to the siUcon content. The x-ray diffraction technique (xrd) also offers a powerfiil means of identifying the various types of asbestos fibers, as well as the nature of other minerals associated with the fibers (9). [Pg.352]

Ion Scattering Spectroscopy (ISS) is one of the most powerful and practical methods of surface analysis available. However, it is undemtilized due to a lack of understanding about its application and capabilities. This stems from its history, the limited number of high-performance instmments manufactured, and the small number of experienced surface scientists who have actually used ISS in extensive applications. Ironically, it is one of the easiest and most convenient sur ce analytical instruments to use and it provides usehil information for almost any type of solid material. [Pg.514]

The bombardment of a sample with a dose of high energetic primary ions (1 to 20 keV) results in the destruction of the initial surface and near-surface regions (Sect. 3.1.1). If the primary ion dose is higher than 10 ions mm the assumption of an initial, intact surface is no longer true. A sputter equilibrium is reached at a depth greater than the implantation depth of the primary ions. The permanent bombardment of the sample with primary ions leads to several sputter effects more or less present on any sputtered surface, irrespective of the instrumental method (AES, SIMS, GDOES. ..). [Pg.106]

Quite generally, each sensitive spectiometric approach today requires instruments of rapidly escalating cost, and these have to be centralised for numerous users, with resident experts on tap. The experts, however, often prefer to devote themselves to improving the instruments and the methods of interpretation so there is a permanent tension between those who want answers from the instruments and those who have it in their power to deliver those answers. [Pg.235]

Sampling for Gases and Vapors Many gases and vapors can be sampled by deviees whieh indicate the eoncentration of the substance during sampling or shortly thereafter, without the necessity for chemical analysis. These direct reading devices are convenient and useful when properly calibrated. Other substances cannot be sampled by this method, because no appropriate instrument is available, and indirect methods which require laboratory analysis of the sample must therefore be used. Such analyses are often delayed by days or weeks, depending upon laboratory schedules. [Pg.265]

Analyses of kinetie data are based on identifying the eonstants of a rate equation involving the law of mass aetion and some transfer phenomena. The law of mass aetion is expressed in terms of eoneentrations of the speeies. Therefore, the ehemieal eomposition is required as a funetion of time. Laboratory teehniques are used to determine the ehemieal eomposition using an instrument tliat is suitably ealibrated to give the required data. The teehniques used are elassified into two eategories, namely ehemieal and physieal methods. [Pg.155]

Various teehniques have been employed for testing and sereening hazardous eompounds produeed in the CPI. The results obtained from these instruments assist the designers and teehnologists in seale-up of the plants. The suitability of the various instruments and test methods... [Pg.924]

Different available measurement instruments and evaluation methods are described in Chapter 12. Some specific methods to evaluate local ventilation systems are described in this section. All local ventilation systems should be evaluated regularly. The evaluation procedures can be divided into detailed and simple, as well as direct and indirect, procedures. The detailed procedures need special instruments and competence, whereas it should be possible to use the simple procedures every day. Since the simple procedures do not measure directly the performance of the exhaust, it is usually necessary to calibrate a simple procedure by using a detailed procedure. ... [Pg.1012]

The probable largest inconsistency in all measurements is the fact that, regardless of the instruments used and the methods applied, we never find the true value of the quantity that is being measured. It is possible to improve the... [Pg.1123]

Qualitative tests and chemical degradation have been to a large degree replaced by instrumental methods of structure determination. The most prominent methods and the str-uctural clues they provide are ... [Pg.519]

It is often experimentally convenient to use an analytical method that provides an instrumental signal that is proportional to concentration, rather than providing an absolute concentration, and such methods readily yield the ratio clc°. Solution absorbance, fluorescence intensity, and conductance are examples of this type of instrument response. The requirements are that the reactants and products both give a signal that is directly proportional to their concentrations and that there be an experimentally usable change in the observed property as the reactants are transformed into the products. We take absorption spectroscopy as an example, so that Beer s law is the functional relationship between absorbance and concentration. Let A be the reactant and Z the product. We then require that Ea ez, where e signifies a molar absorptivity. As initial conditions (t = 0) we set Ca = ca and cz = 0. The mass balance relationship Eq. (2-47) relates Ca and cz, where c is the product concentration at infinity time, that is, when the reaction is essentially complete. [Pg.34]

Delahey, P., New Instrumental Methods in Electrochemistry, Interscience, London (1954) Potter, E. C., Electrochemistry, Principles and Applications, Cleaver-Hume, London (1961)... [Pg.115]

The coil (wound on a light metal former) can be suspended by a fine strip of phosphor bronze between the pole pieces. Attached to this suspension is a small mirror which reflects on to a scale a beam of light which is focused upon it. An instrument of this kind is known as a D Arsonval galvanometer and is used in potentiometer circuits and various methods of measurement of resistance. [Pg.243]

Inhibitor control can be effected by conventional methods of chemical analysis, inspection of test specimens or by instrumentation. The application of instrumental methods is becoming of increasing importance particularly for large systems. The techniques are based on the linear (resistance) polarisation method and the use of electrical resistance probes. They have the advantage that readings from widely separated areas of the plant can be brought together at a central control point. (See Section 18.1.)... [Pg.783]

The purpose for which the analytical data are required may perhaps be related to process control and quality control. In such circumstances the objective is checking that raw materials and finished products conform to specification, and it may also be concerned with monitoring various stages in a manufacturing process. For this kind of determination methods must be employed which are quick and which can be readily adapted for routine work in this area instrumental methods have an important role to play, and in certain cases may lend themselves to automation. On the other hand, the problem may be one which requires detailed consideration and which may be regarded as being more in the nature of a research topic. [Pg.6]

The methods dependent upon measurement of an electrical property, and those based upon determination of the extent to which radiation is absorbed or upon assessment of the intensity of emitted radiation, all require the use of a suitable instrument, e.g. polarograph, spectrophotometer, etc., and in consequence such methods are referred to as instrumental methods . Instrumental methods are usually much faster than purely chemical procedures, they are normally applicable at concentrations far too small to be amenable to determination by classical methods, and they find wide application in industry. In most cases a microcomputer can be interfaced to the instrument so that absorption curves, polarograms, titration curves, etc., can be plotted automatically, and in fact, by the incorporation of appropriate servo-mechanisms, the whole analytical process may, in suitable cases, be completely automated. [Pg.8]

Whilst an instrumental method is ideally suited to the performance of a large number of routine determinations, for an occasional, non-routine, analysis it is often simpler to use a classical method than to go to the trouble of preparing requisite standards and carrying out the calibration of an instrument. [Pg.8]

Clearly, instrumental and classical methods must be regarded as supplementing each other. [Pg.8]


See other pages where Instrumentation and instrumental methods is mentioned: [Pg.269]    [Pg.968]    [Pg.1282]    [Pg.639]    [Pg.640]    [Pg.710]    [Pg.813]    [Pg.402]    [Pg.326]    [Pg.2203]    [Pg.278]    [Pg.7]    [Pg.132]    [Pg.267]    [Pg.274]    [Pg.950]    [Pg.1037]    [Pg.69]    [Pg.139]    [Pg.919]   


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