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The extraction of selected metal ions by an extraction chromatographic (EXC) resin containing N,N,N',N'-tetraoctyl-3,6-dioxaoctane diamide (DOODA) on a porous methacrylate support was measured from nitric acid and hydrochloric acid. Metal ion extraction with the DOODA resin was compared to structurally similar diglycolamide (DGA) resins containing the extractants N,N,N',N'-tetraoctyl-diglycolamide (TODGA; DGA, Normal resin) and N,N,N',N'-tetra(2-ethyl-1-hexyl)-diglycolamide (TEHDGA; DGA, Branched resin). The EXC resins were studied via batch uptake, column elution, extraction capacity, and column stability experiments focusing on potential applications in analytical radiochemistry and nuclear medicine isotope production and purification. The DOODA resin exhibited similar extraction trends to the DGA resins for many metal ions, however, the capacity factors (k') were reduced, typically following the trend of DGA, normal > DGA, branched > DOODA. The selectivity of DOODA resin towards rare earth elements, trivalent actinides, and some transition metal ions, particularly Cd, Ca, and Ac, is quite different from the existing DGA resins, but follows trends previously identified in solvent extraction experiments. The capacity for extraction of Ca(II) and Eu(III) from nitric acid was higher for the DOODA resin than either DGA resin, while all resins exhibited little extractant loss to the mobile phase over >18,000 bed volumes of elution. [ABSTRACT FROM AUTHOR]

The rapid measurement of Ra in steel samples is very important in the event of a radiological emergency. Ra ( T = 1600 y) is a natural radionuclide present in the environment and a highly toxic alpha-emitter. Due to its long life and tendency to concentrate in bones, Ra ingestion or inhalation can lead to significant committed dose to individuals. A new method for the determination of Ra in steel samples has been developed at the Savannah River Environmental Laboratory. The new method employs a rugged acid digestion method that includes hydrofluoric acid, followed by a single precipitation step to rapidly preconcentrate the radium and remove most of the dissolved steel sample matrix. Radium is then separated using a combination of cation exchange and extraction chromatography, and Ra is measured by alpha spectrometry. This approach has a sample preparation time of ~ 8 h for steel samples, has a very high tracer yield (> 88%), and removes interferences effectively. A Ba yield tracer is used so that samples can be counted immediately following the separation method, avoiding lengthy ingrowth times that are required in other methods. [ABSTRACT FROM AUTHOR]

The rapid measurement of Sr in steel samples is important in the event of a radiological emergency as well as for the characterization of routine nuclear decommissioning samples. A new method for the determination of radiostrontium in 1-2 g steel samples has been developed at the Savannah River Environmental Laboratory. The new method employs a rugged acid digestion that includes hydrofluoric acid, followed by a single preconcentration step to rapidly collect the radiostrontium and remove nearly all of the high iron content. A fusion step can be implemented after the steel dissolution when soil, concrete, or highly refractory particles are present. The Sr + Sr and/or Y are separated using extraction chromatographic resins and measured radiometrically, either by gas flow proportional counting or liquid scintillation counting. Several approaches for the measurement of Sr + Sr, Sr, and discrimination between Sr and Sr are discussed. This approach has a sample preparation time of 6-8 h for steel samples. [ABSTRACT FROM AUTHOR]

A new rapid method has been developed that provides high quality low-level measurements of Sr in concrete samples with an minimum detectable activity of <1 mBq g. The new method is fast, meets new decommissioning regulatory limits and is robust even if refractory particles are present. The method utilizes a rapid fusion to ensure total dissolution of samples and rapid preconcentration and separation of Sr from 5 to 10 g concrete samples. When, the Sr/Sr ratio is high, Sr can be isolated from up to 5 g concrete samples, total Sr measured, and then Sr determined via Y separated after a period of ingrowth. Another approach allows the immediate determination of Sr in 10 g concrete aliquots without waiting for Y ingrowth, in instances where the shorter lived Sr is unlikely to be encountered. [ABSTRACT FROM AUTHOR]

A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. This approach has a sample preparation time for limestone and marble samples of <4 h. [ABSTRACT FROM AUTHOR]

A new method that rapidly pre-concentrates and measures Ra from hydraulic fracturing wastewater samples was developed in the Savannah River Environmental Laboratory. The method improves the quality of Ra measurements using gamma spectrometry by providing up to 100 × pre-concentration of Ra from this difficult sample matrix, which contains very high levels of calcium, barium, strontium, magnesium and sodium. The high chemical yield, typically 80-90 %, facilitates a low detection limit, important for lower level samples, and indicates method ruggedness. Ba-133 tracer is used to determine chemical yield and correct for geometry-related counting issues. The Ra sample preparation takes <2 h. [ABSTRACT FROM AUTHOR]