A new mass spectrometer system was developed for studying laser ablation and performing analytical chemistry. The system is based on an ion trap used in an ion-storage (IS) mode, coupled with a reflectron time of flight mass spectrometer (TOFMS). The LA-IS/TOF-MS can be used for MALDI or direct ionization of samples on a probe tip. This paper will describe the system configuration and related operating principles for measuring sensitive and accurate isotopic ratios. Preliminary measurements identified ultra-trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Survey analyses of uranyl acetate, hair samples, and mushrooms demonstrated that this technology can be applied to a wide range of sample materials.

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Yields (%) Substrate Dose ( x loao ev ml.-l) Non-volatile Polymer (non-diffusible) Maltose 4.44 83 1.4 Glucose 1.46 75 1.3 Glucose 4.44 62 45 1 : 4-Gluconolactone 4.54 68 51 Lactic acid 4.54 40 4.8 Glycollic acid 4.54

A comprehensive radiochemical isolation procedure and data analysis/interpretation method for the nuclear forensic investigation of Th has been developed. The protocol includes sample dissolution, chemical separation, nuclear counting techniques, consideration of isotopic parent-daughter equilibria, and data interpretation tactics. Practical application of the technology was demonstrated by analyses of a questioned specimen confiscated at an illegal drug synthesis laboratory by law enforcement authorities. IntroductionThe Isotope Sciences Division and the Forensic Science Center of the Livermore National Laboratory have been developing the discipline of nuclear forensic analysis for several years. Trace radionuclide contaminants and isotopic signatures in nonradioactive species can provide important clues to the origin of a sample. Application of our techniques to specimens of uranium and plutonium has allowed the determination of the types of nuclear reactors used for isotope production, the chemical procedures used during sample purification, and the date on which a specimen was last purified or cast. Such measurements are particularly relevant for the forensic analysis of samples of nuclear materials that are interdicted in countersmuggling operations.The element thorium is as amenable to nuclear forensic techniques as are U and Pu, and radiochemical analyses of trace nuclides in Th can frequently provide information about a specimen that allows it to be traced back to the original ore. The minor Th isotopes provide a means for determining whether the material was recovered and repurified after utilization for the generation of nuclear power. Other radioactive and nonradioactive constituents of a Th specimen can provide clues about separation techniques used in the preparation of the material, as well as the time that the sample was last purified.In addition to the properties that make Th a material of potential interest to nuclear smugglers, thorium oxide can be used to catalyze the production of phenylacetone (P2P) from phenylacetic and acetic acids. 1 P2P is a methamphetamine precursor and a Schedule II controlled substance. Thus, determination of the source and age of illicit Th samples can be of interest outside the traditional nuclear arena, and in activities as seemingly remote as illegal drug manufacture by synthetic organic methods.In this paper, we describe a general and comprehensive method for nuclear forensic analysis of samples containing Th, with the focus on radioactive isotopic signatures. We initially provide a background tutorial on the theory of nuclear forensics, describe an applicable radiochemical separation scheme, and specify radiation counting requirements. These protocols were then implemented to obtain results from a real-world evidentiary specimen, seized in a law-enforcement raid on a clandestine drug lab.

The decomposition of glycollic acid solutions induced by y-radiation in vacuo and in the presence of oxygen has been followed quantitatively. The concentrations of glycollic, glyoxylic, tartaric, oxalic, and formic acid, formaldehyde, and carbon dioxide have been measured directly, and by new colorimetric methods in the cases of glycollic and glyoxylic acid. A mass balance for carbon has been obtained, and degradation pathways are advanced to explain the results.