Environmental samples, radiochemical analysis

Cooper EL, Milintawisamai M, Panyatipsakul Y. 1993. Implementation of a radiochemical procedure for the analysis of isotopes of Pu, Am and Cm in food and environmental samples. Sci Total Environ 130/131 177-186. 

Long-lived radionuclides occur at extremely low concentrations, especially in environmental samples, therefore several authors have proposed matrix separation and enrichment of the analytes before analysis.21,24,26,3 39 Radiochemical methods often require very careful and time consuming separation and enrichment processes and measurement procedures of a-, (3- and -emitting radioactive species at the trace and ultratrace level using conventional radioanalytical techniques 40-43 Trace/matrix separation, which is performed offline or online in order to avoid possible isobaric interferences, matrix effects and to reduce the detection limits for the determination of long-lived radionuclides, is also advantageous before ICP-MS measurements as the most widely applied mass spectrometric technique. 

The spectrometer has also been applied successfully to the counting of environmental samples contaminated with worldwide fallout, reactor effluent, and debris from nuclear cratering experiments. In addition, it has been possible to carry out a variety of laboratory experiments not practical in the past because of the need for laborious radiochemical analysis such experiments have involved the analysis of several hundred samples each containing up to 20 isotopes. 

X-ray and Coincidence Spectrometry Applied to Radiochemical Analysis of Environmental Samples... 

Radiochemical analysis will continue to be important in many aspects of the use of nuclear fuels, including spent-fuel analysis monitoring reprocessing for process performance or safeguards analyzing environmental samples for contamination and... 

The radioanalytical methods of determining 55Fe and 63Ni were worked out by Holm et al.6 and Skwarzec et al.11 Figures 11.1 and 11.2 illustrate the procedures for the radiochemical analysis of 55Fe and 63Ni in aquatic environmental samples. 

Johns, F.B., et al., Radiochemical Analytical Procedures for Analysis of Environmental Samples, EMSL-LV-0529-17, USEPA, Las Vegas, NV (1979). 

NAA has been used to determine selenium levels in environmental samples. Dams et al. (1970) reported a detection limit of lxlO 10 g/m3 selenium using nondestructive NAA for determining selenium in air particulate matter. For determining selenium levels in soil, radiochemical variants of NAA have been commonly employed (Bern 1981). Instrumental neutron activation analysis (INAA) is frequently used to determine selenium concentrations in water and can also be used to distinguish between selenium(IV) and selenium(VI) oxidation states (Bern 1981). INAA is also used to determine selenium concentrations in air (Bern 1981). 

An accuracy of 0.2 ng has been reached in the analysis of biological and environmental samples containing about 4 ng Au on irradiation in the thermal neutron flux of 1 x 1013 n cm 2 s 1 during 6 days652 and subsequent radiochemical separation. 4.7 ppb and 1.9 ppb of Au was detected653 by INAA in two human kidney stones (one oxalate and one phosphate). There are indications that the trace element content of hair correlates with the body stores of these elements, particularly with those of bone654. The INAA of hair samples taken from osteoporosis patients showed 2.32 1.32 ngg 1 content of Au in osteoporotic hair and 3.57 1.90 ngg-1 in normal hair655. 

Radioiodine plays an important role in the diagnosis and treatment of various thyroid disorders. Production methods for various iodine isotopes, namely, and are briefly described in this paper. The chemistry of iodine and radiation effects in aqueous solutions and isotopic exchange reactions are also reviewed. An understanding of the chemistry of iodine is essential in isotope production, and for developing the procedure to prepare the radioactive iodine labeled pharmaceuticals. In radiochemical analysis of iodine, most environmental and biological samples can be accurately analyzed by neutron activation at trace levels. The use of potassium iodide (KI) has become an important remedy to prevent the harmful effects of radioiodine exposure under nuclear accident conditions. The inhibitory effect of KI administration on thyroid radioactive iodine uptake is discussed. 

The analysis of trace iodine in biological, as well as environmental, samples is of immense interest in this review. Special attention is given to the radiochemical analysis with neutron activation of I and I. 

Chemical analysis of trace iodine, in either biological or environmental samples, always encounters problems of interference from impurities and uncertainty in chemical yield of analysis. As discussed previously in Chemistry of Iodine Relevance to Radiochemical Studies and Nuclear Properties of Iodine Isotopes , the chemistry of iodine is very complex and isolation or purification of iodine from the sample is a major obstacle in a traditional chemical analysis. 

All chromatographic methods (liquid, liquid-liquid, liquid-solid, gas, gas-liquid, and gas-solid chromatography) are used in radiochemical analysis of food and environmental samples. Equipment for the evaluation of paper and thin-layer radiochromatograms is commercially available. The radiation detectors used vary according to the type and energy of the radiation emitted by the measured radionuclides. Use is made of ionization chambers, proportional counters, and Geiger-Miiller, scintillation, and semiconductor detectors. 

Dermelj M and Byrne AR (1997) Simultaneous radiochemical neutron activation analysis of iodine, uranium and mercury in biological and environmental samples. Journal of Radioanalytical and Nuclear Chemistry 216 13-18. 

Glover et al. (1998, 2001) developed an ultra-sensitive method for the analysis of Th in bioassay and environmental samples and pre-concentration radiochemical neutron activation analysis (PC-RNAA) was applied. In the pre-irradiation procedure, Th was concentrated using... 

Since some detectors are unable to discriminate between radioisotopes, e.g. proportional counters, and others require a sample matrix clean-up, sample pretreatment is very often unavoidable. Thus, radionuclides are isolated before measurement to avoid the presence of other radionuclides and interfering elements, and therefore radiochemical methods usually include separation steps in their protocols. Apart from a limited number of radionuclides that can be analyzed by high-resolution gamma spectrometry, e.g. " Mn, °Co, " Cs, Cs, " Eu, Eu, and Sb, direct analysis is impossible, that is the sample needs to be previously chemically processed. Furthermore, if samples to be analyzed have low activities, e.g. environmental samples, a preconcentration procedure is mandatory. 

Fajardo, Y., J. Avivar, L. Ferrer, E. Gomez, M. Callas, and V. Cerda. 2010. Automation of radiochemical analysis by applying flow techniques to environmental samples. Trends Anal. Chem. 29 1399—1410. 

Brauer, F.P. and Kaye, J.H. (1974). Detection systems for the low-level radiochemical analysis of iodine-131, iodine-129, and natural iodine in environmental samples, IEEE Trans. Nucl. Sci. 21,446. 

Brauer, F. P. and Kaye, J. H. Detection Systems for the Low-Level Radiochemical Analysis of Iodine-131, Iodine-129, and Natural Iodine In Environmental Samples. IEEE (Inst. Elec. Electron. Eng.), Trans. Nucl. Scl. NS-iL. No. 1, 496 (1974). 30 5867... 

CLOR. 1978. Procedure for radiochemical and chemical analysis of environmental and biological samples. Raport no. CLOR-110/D, Centralne Laboratorium Ochrony Radiologicznej, Warszawa. 

WiLDHAGEN D and Keivan V (1993) Determination of platinum in environmental and geological samples by radiochemical neutron activation analysis. Anal Chim Acta 274 257-266. 

The application of microtron photon activation analysis with radiochemical separation in environmental and biological samples was described by Randa et al. (2001), and both flame and plasma emission spectroscopic methods are also widely used. A more recently developed technique is that of laser-excited atomic fluorescence spectrometry (LEAFS) (Cheam et al. 1998). 

Randa Z, Kucera j and Soukal L (2001) Possibilities of simultaneous determination of lead and thallium in environmental and biological samples by microtron photon activation analysis with radiochemical separation. J Radioanal Nucl Chem 248 149-154. 

The analysis of iodine at trace levels is reviewed in detail. Classical radiochemical procedures commonly been used in various samples, but neutron activation is probably more popular in environmental and biological samples. Gamma-spectrometric methods are often used in conjunction with Nt A. 

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