Uranium analysis

UraniumCVI) carbonate solids, 25 431 UraniumCVI) orthophosphates, 25 433 Uranium-aluminum alloys, 25 421 Uranium analysis... 

Several methods that do not require chemical separation are available for measuring uranium in urine (in units of total mass or total activity). These methods include spectrophotometric (total mass), fluorometric (total mass), kinetic phosphorescence analysis (KPA) (total mass), and gross alpha (total activity) analyses (Wessman 1984). The most widely used methods for routine uranium analysis are a-spectrometry and liquid scintillation spectrometry. These methods utilize the natural radioactivity of uranium and are sensitive and require little sample preparation. Photometric techniques such as fluorometry and phosphorometry are less widely used, but kinetic phosphorescence analysis is becoming more widely used. Measurements of total uranium do not provide the relative isotopic abundance of the uranium isotopes, but this may only be important when converting between activity and mass when the isotopic ratios are uncertain. 

Considerable work has been done to develop methods for analysis of uranium in water. In 1980, the EPA published standardized procedures for measurement of radioactivity in drinking water which included uranium analysis by both radiochemical and fluorometric methods (Krieger and Whittaker 1980), and more recently developed an ICP-MS method. An example of each is provided below. 

Problem Pitchblende is the most commercially important compound of uranium. Analysis shows that 84.2 g of pitchblende contains 71.4 g of uranium, with oxygen as the only other element. How many grams of uranium can be obtained from 102 kg of pitchblende ... 

As an example, consider a client who requires total uranium analysis of 600 samples to be delivered at the beginning of each quarter. If the analysis schedule indicates a processing rate of 60 samples per day, then the sample load requires a minimum of 10 days for analysis. This period must include the following activities ... 

Standard Test Method for Analysis of Uranium and Thorium in Soils by Energy Dispersive X-Ray Fluorescence Spectroscopy Standard Test Method for Determination of Low Concentrations of Uranium in Oils and Organic Liquids by X-Ray Fluorescence Standard Test Method for Uranium Analysis in Natural and Waste Water by X-Ray Fluorescence... 

Neutron activation analysis is a sensitive technique for uranium analysis, but its use is limited by access... 

The majority of samples collected for uranium analysis have been urinary bioassay specimens from workers in the nuclear industry. Typically these measurements are performed to ascertain that the worker exposures are below a set limit. Aerosol samples from area monitors and personal samplers are routinely measured to estimate and minimize exposure levels. The exposure and bioassay results can be combined to produce improved metabolic models for the retention and elimination of uranium from humans. 

The quanitity of the raw material necessary to produce a reliable estimate of any element will depend on the selected detection instrument. In general, samples for uranium analysis are preconcentrated by evaporation, air-, freeze-, or oven-drying to remove water, and dry-ashing or wet-ashing to remove carbonaceous matter. For vegetation and soil, acid or alkali fusion followed by acid dissolution of the fusion cake is required to ensure dissolution of refractory materials. Aerosol, water, soft tissues, blood, and dry-ashed bone samples may be solubilized with mineral acids. 

Amoli, H.S., Barker, J., and Flowers, A. (2007). Closed vessels microwave digestion method for uranium analysis of soils using alpha spectroscopy, J. Radioanal. Nucl. Chem. TTi. 281-284. 

Ejnik, J.W, Todorov, T.I., MuUick, EG. et al. (2005). Uranium analysis in urine by inductively coupled plasma dynamic reaction cell mass spectrometry. Ana/. Bioanal. Chem. 382,73-79. 

Todorov, T.I., Xu, H., Ejnik, J.W. et al. (2009). Depleted uranium analysis in blood by inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom. 24,189-193. 

As mentioned earlier, UCFs process mainly natural uranium so that the presence, or operation, of a clandestine UCF may be difficult to identify by uranium analysis alone or even by isotopic composition measurements. However, the co-existence of uranium and fluorine in micrometer-sized particles can help recognize such an operation (Faure et al. 2014). SIMS methodology was used for this purpose on two real-life UF4 samples collected on filters and cotton cloth swabs in the purification and fluo-rination workshops and two CRM standards (CRM UF4 and CRM UOC) were used for calibration. In addition, two swipe samples, to which a relatively large amount of... 

Pestana, R.C.B., Sarkis, J.E.S., Marin, R.C. et al. (2013). New methodology for uranium analysis in swipe samples for nuclear safeguards purposes, J. Radioanal. Nucl Chem. 298, 621-625. 

Accurate uranium analysis, particularly for isotope measurements, is essential in many fields, including environmental studies, geology, hydrogeology, the nuclear industry, health physics, and homeland security. Nevertheless, only a few scientific books are dedicated to uranium in general and analytical chemistry aspects in particular. Analytical Chemistry of Uranium Environmental, Forensic, Nuclear, and Toxicological Applications covers the fascinating advances in the field of analytical chemistry of uranium. 

Cazoulat, A., Lecompte, Y., Bohand, S., et al, 2008. Urinary uranium analysis results on Gulf war or Balkans conflict veterans. Pathologie-biologie 56,77-83. 

The first application of ICP-MS for environmental radionuclide analysis was probably for the determination of thorium and uranium. The first paper describing uranium analysis of environmental samples was published by Boomer and Powell in 1987. In this work, they analysed seven environmental standard reference materials (SRMs). Igarashi et al. reported results for Th and U concentration in human bone and tissues in 1991. In addition, another (unique) report was also presented by Igarashi et al. in 1991. In this study, the authors determined Th in a thorotrast patient s liver. After these publications, the number of Th and U analysis papers rapidly increased, and ICP-MS is now the most popular analytical technique for determining these elements in both environmental and biological samples. 

Betelu S, Vautrin-Ul C, Ly J, Chausse A (2009) Screen-printed electrografted electrode for trace uranium analysis. Talanta 80 372-376... 

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