Radiochemical activation analysis

Activation analysis may be applied in many variants. Neutron activation analysis (NAA) is the most widely used, but often charged particle activation or photon activation are more advantageous. If the energy of the projectiles can be varied, many variations are possible. The application of the manifold methods of activation depends on the availability of research reactors and accelerators. In addition, purely instrumental or radiochemical methods may be used. In instrumental activation analysis, the samples are measured after irradiation without chemical separation, whereas radiochemical activation analysis includes chemical separation. 

Orvini, E. and Delfanti, R. (1979). Determination of arsenic at nanogram level in biological tissues by radiochemical activation analysis, Radiochem. Radioanal. Letters,, 199-206. 

In radiochemical activation analysis (RAA), the various techniques of activation analysis (AA), i.e., neutron activation analysis (NAA), photon activation analysis (PAA), and charged particle activation analysis (CPAA) are combined with radiochemical separation procedures with the intention of extending the capabilities offered by the purely instrumental methods. 

A recently defined and new objective has been trace element speciation, which provides information about the physical/chemical state of the trace elements. Species separated by chemical methods are subsequently determined by instrumental or radiochemical activation analysis. 

The term RAA is used for the conventional form of radiochemical activation analysis with post-irradiation chemical processing, as well as - in a broad sense—for all types of AA involving chemical and radiochemical operations. 

The apphed pretreatment techniques were digestion with a combination of acids in the pressurized or atmospheric mode, programmed dry ashing, microwave digestion and irradiation with thermal neutrons. The analytical methods of final determination, at least four different for each element, covered all modern plasma techniques, various AAS modes, voltammetry, instrumental and radiochemical neutron activation analysis and isotope dilution MS. Each participating laboratory was requested to make a minimum of five independent rephcate determinations of each element on at least two different bottles on different days. Moreover, a series of different steps was undertaken in order to ensure that no substantial systematic errors were left undetected. 

Byrne AR, and Kucera J (1991) Radiochemical neutron activation analysis of traces of vanadium in biological samples A comparison of prior dry ashing with post-irradiation wet ashing. Fresenius f Anal Chem 340 48-52. 

Byrne AR, and Versieck J (1990) Vanadium determination at the ultratrace level in biological reference materials and serum by radiochemical neutron activation analysis. Biol Trace Elem Res 27 529-540. 

Byrne AR, Deemelj M, Kosta L, and Tusek-Znidaric M (1984) Radiochemical neutron activation analysis in standardization of trace elements in biological reference materials at the nanogram level. Mikrochim Acta [Wien] 1 119-126. 

Kucera J, and Soukal L (1993) Determination of As, Cd, Cu, Hg, Mo, Sb and Se in biological reference materials by radiochemical neutron activation analysis. J Radioanal Nud Chem 168 185-199. 

Pietra, R., Fortaner, S., and Sabbioni, E. (1993). Use of Chelex 100 resin in preconcentration and radiochemical separation neutron activation analysis applied to environmental toxicology and biomedical research. /. Trace Microprobe Tech. 11, 235-250. 

The characteristics of radiochemical methods are well known [435]. An overview of the determination of elements by nuclear analytical methods has appeared [436]. Some selected reviews of nuclear methods of analysis are available charged particle activation analysis [437,438], instrumental neutron activation analysis [439-441] and ion-beam analysis [442]. 

Activation analysis, the application of radiotracers and other radiochemical methods in innovative trace analysis are indispensable, first of all in the preparation of standard reference samples. 

The need for special facilities for work involving neutron activation analysis and radiochemical measurements has been referred to above in Section 4.3.6. Other safety factors may also influence your choice of method. For example, you may wish to avoid the use of methods which require toxic solvents, such as benzene and certain chlorinated hydrocarbons, or toxic reagents, such as potassium cyanide, if alternative procedures are available. Where Statutory Methods have to be used, there may be no alternative. In such cases, it is essential that staff are fully aware of the hazards involved and are properly supervised. Whatever method is used, the appropriate safety assessment must be carried out before the work is started. Procedures should be in place to ensure that the required safety protocols are followed and that everyone is aware of legislative requirements. 

Olariu, A., Constantinescu, M., Constantinescu, O., et al. (1999). Trace analysis of ancient gold objects using radiochemical neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry 240 261-267. 

Radiochemical purification, activation analysis and, 1 322-323 Radio-frequency plasmas commercial applications of, 17 110, 111 economics of, 17 111, 112 use of, in chemical synthesis, 17 89-112 Radioisotopes, use in medical diagnosis and imaging, 36 25-26... 

During the late 1960s and early 1970s, neutron activation analysis provided a new way to measure bulk chemical composition. Neutron activation analysis utilizes (n,y) reactions to identify elements. A sample is placed in a nuclear reactor where thermal neutrons are captured by atoms in the sample and become radioactive. When they decay, the radioactive isotopes emit characteristic y-rays that are measured to determine abundances. Approximately 35 elements are routinely measured by neutron activation analysis. A number of others produce radioactive isotopes that emit y-rays, but their half-lives are too short to be useful. Unfortunately, silicon is one of these elements. Other elements do not produce y-ray-emitting isotopes when irradiated with neutrons. There are two methods of using neutron activation to determine bulk compositions, instrumental neutron activation analysis (INAA) and radiochemical neutron activation analysis (RNAA). 

Applications of Radiochemical Methods to Analytical Chemistry)(In col lab with T.C.Castorina, PicArsn). Activation analysis is the quantitative detn of elements by the measurement of the radioactivity produced in them by nuclear bombardment... 

Trace Elements in Coal by Neutron Activation Analysis with Radiochemical Separations... 

Procedures for the determination of 11 elements in coal—Sb, As, Br, Cd, Cs, Ga, Hg, Rb, Se, U, and Zn—by neutron activation analysis with radiochemical separation are summarized. Separation techniques include direct combustion, distillation, precipitation, ion exchange, and solvent extraction. The evaluation of the radiochemical neutron activation analysis for the determination of mercury in coal used by the Bureau of Mines in its mercury round-robin program is discussed. Neutron activation analysis has played an important role in recent programs to evaluate and test analysis methods and to develop standards for trace elements in coal carried out by the National Bureau of Standards and the Environmental Protection Agency. 

Versieck, J. and L. Vanbalieiibeighe Determination of Tin in Human Blood Semm by Radiochemical Neutron Activation Analysis,1 Analytical Chemistry. 1143 (June... 

For the following analyses, indicate whether radiochemical neutron activation analysis would be preferred to instrumental neutron activation analysis. If radiochemistry is indicated, briefly sketch the separation procedures to be used (a) the determination of ppm levels of Mo in flathead minnows, (b) the determination of the trace-element content of agricultural field-burning particulate matter, (c) the use of stable activable tracers to determine flow patterns in an ocean estuary, and (d) the determination of Dy in pine needles. 

Tomza U, Janicki T, Kossman S. 1983. Instrumental neutron activation analysis of trace elements in hair A study of occupational exposure to a non-ferrous smelter. Radiochem and Radioanal Letters 58 209-220. 

Neutron activation analysis techniques are frequently used for trace element analyses of coal and coal-related materials (Weaver, 1978). Precision of the method is 25%, based on all elements reported in coal and other sample matrices. Overall accuracy is estimated at 50%. Neutron activation analysis utilizing radiochemical separations (NAA-RC) is employed by investigators when the sensitivity for a particular element or group of elements is inherently low or when spectral interference for a given element in a specific matrix is too great to be detected adequately. This situation was more prevalent before the advent of Ge(Li) spectrometry when only low-resolution Nal(TI) detectors were available. 

Radiochemical Methods in Analytical Chemistry. Activation Analysis with Gamma-Ray Photons and Charged Particles. Chimica 21, No. 3, 116 (1967). 

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