Radionuclide sensors

Some extractants have been used in the development of selective sensors for radionuclides. These have been noted in Tables 9.1 through 9.3 and briefly mentioned above. They were recently reviewed in detail.99 In addition to column sensor formats, extractants have been coated onto passivated ion-implanted planar silicon (PIPS) diodes to create selective radionuclide sensors.152153 Though not a focus of this review, it is worth noting the such sensors, combining separation and detection in a single functional unit, have potential for use in process-monitoring applications. 

Egorov, O. B., Fiskum, S. K., O Hara, M. J., and Grate, J. W., Radionuclide sensors based on chemically selective scintillating microspheres Renewable column sensor for analysis of 99Tc in water, Anal. Chem., 71, 5420-5429, 1999. 

This configuration meets all die fimctional requirements for effective radionuclide sensors. The packed column format provides for efficient fluidic processing of the sample for preconcentration. The detection method is radiometric via die process of scintillation. Selective chemistry is in very close proximity to the scintillation material and retains the radionuclides for counting. These new column sensors represent a novel and advantageous approach for detection of radionuclides vdien selective preconcentration is required. 

Regarding to the online connectivity of the detectors, LSCs [20,21] together with its modified versions for radionuclide sensors [22—24] and ICP-MS [25—27] have been successfully coupled to... 

J.W. Grate, O. Egorov, M. O Hara, T.A. DeVol, Radionuclide sensors for environmental monitoring from flow injection solid-phase absorptiometry to equilibration-based preconcentrating minicolumn sensors with radiometric detection, Chem. Rev. 108 (2008) 543—562. 

Gamma EDR in air and water was entirely determined by cosmic rays, whereas in bottom sediments - by natural-origin radionuclides. Depth-depending increase in the counting rate of PRM-K scintillation sensor (from 50-m depth and below) within all energy ranges (Fig.3), save for 1.8-2.5 MeV (Fig. 4b), was due to natural factors -namely to increase in salinity, thus of concentration, with depth. 

A variety of assay formats are used with immuno. sensors, One of ihe most common methods u.sc.s two an-lib()dies, one that is immobilized on the sensor surface and is used in capture the target analyte, and one ihai is labeled and is used to detect the captured analyte (a [Pg.733]

Although there are many radioactivity detectors available, there has been very little development of analytical instruments or radiochemical sensors suitable for rapid and selective quantification of beta- and alpha-emitting radionuclides such as c, Sr, and TRU actinides in water or process streams. Current baseline analytical methods for these analytes are based on tedious manual radiochemical analysis methods performed in centralized laboratories. 

Figure 1. Preconcentrating minicolumn sensor concept for selective capture of radionuclides with transduction to a light output signal by the process of...

Our initial work in automating laboratory analysis of radionuclides in nuclear waste has now advanced to the development of sensors and instruments for nonlaboratory settings. Our sensor for Tc in groundwater was selected for prototype engineering development, and a field test was conducted at the Hanford site in September 2002. This unit successfully quantified the Tc activity in Hanford groundwater samples. The automated Tc analyzer has been under development for use at the Hanford site, and was selected in a conqietitive process for incorporation into the Hanford Waste Treatment Plant. 

In contrast, the five remote sensor technologies for detecting and identifying underwater or underground nuclear tests (radionuclide, seismic, infrasound, hydroacoustic, and... 

Online detection of radionuclides is also integrated in sensors developed for environmental monitoring. Sensors are constituted by a preconcentrating minicolumn packed with scintillating microspheres, which integrates radiochemical separation and radiometric detection steps within a... 

K. D. Abney, T. M. Foreman, R. J. Butcher, S. A. Kinkead, New synthetic routes to b-halogenated derivatives of cobalt dicarbollide, Inorg. Chem. 1995, 34, 5215 (c) C. Vinas, S. Gomez, J. Bertran, J. Barron, F. Teixidor, J.-F. Dozol, H. Rouquette, R. KivekSs, R. SiUanpaa, C-substituted bis(dicarbollide) metal compounds as sensors and extractants of radionuclides from nuclear wastes, J. Organomet. Chem. 1999, 581, 188 (d) C. Vinas, S. Gomez, J. Bertran, F. Teixidor, J.-F. Dozol, H. Rouquette, New polyether-substituted metallacarboranes as extractants for Cs and Sr from nuclear wastes, Inorg. Chem. 1998, 37, 3640. 

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