Flame photometry applications

Instrumentation. Flame Characteristics. Flame Processes. Emission Spectra. Quantitative Measurements and Interferences. Applications of Flame Photometry and Flame Atomic Emission Spectrometry. 

Applications of Flame Photometry and Flame Atomic Emission Spectrometry... 

Estrogens, Natural, the Determination and Significance of (Brown), 3, 158 Flame Photometry (MacIntyre), 4, 1 Flocculation Tests and their Application to the Study of Liver Disease (Reinhold), 3, 84... 

Flame photometry is the name given to the technique that measures the intensity of the light emitted by analyte atoms in a flame. It is the oldest of all the atomic techniques. It is not highly applicable because of the low temperature of the flame. Only a handful of elements can be measured with this technique, including sodium, potassium, lithium, calcium, strontium, and barium. The technique was formerly used... 

Five liquid membrane electrodes (Table 13.3) are now commercially available and have found wide application in the testing of electrolytes in biological and technological systems. All five electrodes perform well in the concentration range over which the Nernstian slope is maintained, i.e., from 10 -10 moldm . These electrodes to a certain extent have replaced in both chemical and clinical laboratories the more traditional instrumental methods of analysis, such as flame photometry and atomic absorption spectrometry. There are, of course, many more liquid membrane electrodes, but the availability of satisfactory solid electrodes has greatly restricted their development and practical application. 

Atomic absorption and flame emission spectroscopy, also called flame photometry, are two methods of quantitative analysis that can be used to measure approximately 70 elements (metals and non-metals). Many models of these instruments allow measurements to be conducted by these two techniques, which rely on different principles. Their applications are numerous, as concentrations in the mg/l (ppm) region or lower can be accessed. 

BurrieTMarti, F., and J. Ramirez-Munoz Flame Photometry. A Manual of Methods and Applications, 3. Edition. Amsterdam Elsevier Publ. 1960. 

Flame photometry has promise for the measurement of sodium, lead, and potassium. An application to measurement of sodium and alkali metals has been reported. The continuous measurement of sulfur-containing particles has received considerable attention. The motivation for observation of sulfur-containing particles comes from concern about the potential hazard posed by sulfate in the atmosphere. 

Each spectroscopic method has a characteristic application. For example, flame photometry is still applicable to the direct determination of Ca and Sr, and to the determination of Li, Rb, Cs and Ba after preconcentration with ion-exchange resin. Fluorimetry provides better sensitivities for Al, Be, Ga and U, although it suffers from severe interference effects. Emission spectrometry, X-ray fluorescence spectrometry and neutron activation analysis allow multielement analysis of solid samples with pretty good sensitivity and precision, and have commonly been applied to the analysis of marine organisms and sediments. Recently, inductively-coupled plasma (ICP)... 

Flame Photometry, Principles and Applications (Margoshes and Vallee). 3 353... 

APPLICATIONS OF FLAME PHOTOMETRY . /lND FLAME - ATOMIC EMISSION SPECTROMETRY... 

Analytical applications have been found for all parts of the electromagnetic spectrum ranging from microwaves through visible radiation to gamma (y) rays (Table 1). The emission and absorption of electromagnetic radiation are specific to atomic and molecular processes and provide the basis for sensitive and rapid methods of analysis. There are two general analytical approaches. In one, the sample is the source of the radiation in the other, there is an external source and the absorption or scattering of radiation by the sample is measured. Emission from the sample may be spontaneous, as in radioactive decay, or stimulated by thermal or other means, as in flame photometry and fluorimetry. Both approaches can be used to provide qualitative and quantitative information about the atoms present in, or the molecular structure of, the sample. 

D5. Dawson, J. B., The application of photon counting techniques to flame photometry. Method. Phys. Anal., No. Spec. Sept., 32-38 (1971). 

With the use of fuels that produced hotter flames, earlier flame photometers became useful for analyzing elements beyond the alkali and alkaline earth metals. The development of atomic absorption spectrophotometers in the late 1960s provided the analytical chemist with a better tool for many of these applications. Later developments in high-temperature flame photometry narrowed the analytical applications of low-temperature flame photometry even further. The utility of the flame photometer to the clinical chemist, however, was not diminished until the development... 

The analysis of clinical samples represents a typical application of flame photometry. Concentrations of sodium, potassium, and lithium in blood and urine are well within instrument working ranges. The specificity of the technique is a distinct advantage. Automated models of flame photometers, available during the past 25 years, are typically designed to serve the needs of the clinical chemist. Instrument calibration protocols are built into instruments to facilitate the timely analysis of sodium, potassium, and lithium in clinical samples. 

There are at least 25 USP or BP formulation monographs that use flame photometry to assay ions of interest (Table This technique is applicable to a variety of situations because of the relatively low cost per sample (in analyst time, instrument capital expense, and testing supplies) reasonable precision (typical relative standard deviation values are 0.6% for sodium, 1% for potassium, and 2% for lithium) low sample volume requirements (as low as 10 pi in some cases) and ease of operation. 

Because carbon dioxide is nonpolar, the separation of polar compounds by supercritical carbon dioxide is difficult. Thus, polar modifiers are often used for the separation of phenols and amines. Derivatization has also been employed to obtain nonpolar analytes in some applications. The UV detector has mainly been used for the detection of polar compounds. Oxidative and reductive amperometric detection was also utilized with a detection limit of 250 pg for oxidative detection of 2,6-dimethylphenol. The detection of amines has generally been achieved by FID. Other detectors used for the detection of polar analytes include Fourier transform infrared (FTIR), photodiode array, and flame photometry. 

A variety of electrochemical methods have been incorporated into automated systems. The most widely used Mec-trochemical approach involves ion-selective electrodes. These electrodes have replaced flame photometry for the determination of sodium and potassium in many analyzers and have lately found direct application in the measurement of other electrolytes and indirect application in the analysis of several other serum constituents. The operating principle of ion-selective electrodes is given in some detail in Chapter 4. The relationship between ion activity and the concentration of ions in the specimens must be established with calibrating solutions, and frequent recalibration must be done to compensate for alterations of electrode response. 

It is the object of this review to provide a critical account of modem flame photometry in the light of the basic principles of the method. No attempt has been made to provide a catalog of the innumerable articles appearing on the subject, but it is hoped that this chapter will help clinical chemists to decide whether flame photometry is applicable to a particular problem and perhaps to suggest ways of overcoming diflBculties with the method. 

Volume 4 of this series covers again aspects of Clinical Chemistry ranging from discussions of analytical methods to reviews on the biochemistry of disease, centering around the physiology and pathology, for instance, of a hormone or of a vitamin, and including the pertinent chemical procedures. Recent developments in immunoelectrophoresis, microliter analysis, and flame photometry are treated with a view to their concrete applications. 

A simple example serves to illustrate the use of these statistics in reducing data to key statistical values. Table 1.1 gives one day s typical laboratory results for 40 mineral water samples analysed for sodium content by flame photometry. In analytical science it is common practice for such a list of replicated analyses to be reduced to these descriptive statistics. Despite their widespread use and analysts familiarity with these elementary statistics care must be taken with their application and interpretation in particular, what underlying assumptions have been made. In Table 1.2 is a somewhat extreme but illustrative set of data. Chromium and nickel concentrations have been determined in waste water... 

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