D. Gallimore

Inductively Coupled Plasma-Mass Spectrometry of Synthetic Elements: 99Tc:

In the current social climate of growing environmental responsibility and concern, the public interest demands that the nuclear industry effectively monitor the environmental consequences of fuel production, reprocessing, and waste disposal. Furthermore, for protection of worker safety and national security, operational importance is also placed upon controlling production and disposal of synthetic elements. Therefore, the selection of appropriate analytical techniques for environmental surveillance and process control of radionuclides must satisfy these criteria.

Determination of trace impurities in uranium oxides by laser ablation inductively coupled plasma mass spectrometry

Laser ablation inductively coupled plasma mass spectrometry was used to perform a semi-quantitative determination of 23 impurity elements in a U3O8 certified reference material (CRM). Matrix-matched, single-point calibration was achieved by using another CRM from the same series of standards. Based on uncertainties derived from error propagation, most measured concentrations fell within one standard deviation of certified values. Under optimum laser sampling conditions, limits of detection (LODs) for low m/z elements were found to be about 1 µg g–1; high m/z elements had LODs approximately 100 times lower. Upper limits of quantification were generally in the low mg g–1 range. Median short-term signal reproducibility was 8% relative standard deviation when an internal reference isotope (234U) was used. Reproducibility was poorer when the internal reference was not used or when the same area of the target was ablated in replicate.

Elemental composition in sealed plutonium-beryllium neutron sources.

Five sealed plutonium-beryllium (PuBe) neutron sources from various manufacturers were disassembled. Destructive chemical analyses for recovered PuBe materials were conducted for disposition purposes. A dissolution method for PuBe alloys was developed for quantitative plutonium (Pu) and beryllium (Be) assay. Quantitation of Be and trace elements was performed using plasma based spectroscopic instruments, namely inductively coupled plasma mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). Pu assay was accomplished by an electrochemical method. Variations in trace elemental contents among the five PuBe sources are discussed.

Determination of neptunium in plutonium materials by ICP-MS

An ICP-MS analytical method as an alternative to the current radiochemical method was developed to analyze trace level 237Np in bulk plutonium materials. In this method, 237Np is determined together with a suite of trace elements during a single analysis using one dissolution solution. Method validation was achieved through precision examination, spike recovery study, detection limit determination, comparison of results with the radiochemical method, and laboratory intercomparison studies on Pu metals. The ICP-MS method significantly reduced the analysis cost, the sample amount, consumption of chemicals and waste generation, as well as the sample turnaround time.

Plutonium oxalate precipitation for trace elemental determination in plutonium materials

An analytical chemistry method has been developed that removes the plutonium (Pu) matrix from the dissolved Pu metal or oxide solution prior to the determination of trace impurities that are present in the metal or oxide. In this study, a Pu oxalate approach was employed to separate Pu from trace impurities. After Pu(III) was precipitated with oxalic acid and separated by centrifugation, trace elemental constituents in the supernatant were analyzed by inductively coupled plasma-optical emission spectroscopy with minimized spectral interferences from the sample matrix.

Inductively coupled plasma—mass spectrometry drift correction based on generalized internal references identified by principal components factor analysis

Abstract Abstract factor analysis is applied to repeated measurements of inductively coupled plasma—mass spectrometry (ICP-MS) responses for several elemental masses in a multielement standard. During good operation, over 90% of the variance in response is accounted for by two or three factors. These factors tend to correlate with different mass ranges, and these correlations allow a rational basis for selection of candidates for internal reference elements. Internal references selected from these candidates were used to evaluate three different mathematical methods for correcting ICP-MS responses of all elements. The line ratio internal reference method and the analyte internal reference correlation method, which use a single internal reference for all elemental masses, improved precisions for most elements but decreased or had no effect on precisions of other elements. The generalized internal reference method, which may use more than one elemental mass in the correction calculation, improved precisions for all elements in most experiments.