Scott N Willie

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A new selenized yeast reference material (SELM-1) produced by the Institute for National Measurement Standards, National Research Council of Canada (INMS, NRC) certified for total selenium (2,059+/-64 mg kg(-1)), methionine (Met, 5,758+/-277 mg kg(-1)) and selenomethionine (SeMet, 3,431+/-157 mg kg(-1)) content is described. The +/-value represents an(More)
A suite of three ginkgo-containing dietary supplement Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST) with certified values for flavonoid aglycones, ginkgolides, bilobalide, and selected toxic trace elements. The materials represent a range of matrices (i.e., plant, extract, and finished(More)
A simple, rapid and reliable method was developed for the determination of total mercury in biological samples. Samples were solubilized using tetramethylammonium hydroxide (TMAH). The organically bound mercury was cleaved and converted to inorganic mercury by on-line addition of KMnO4. The decomposed mercury together with inorganic mercury originally(More)
A GC-ICP-MS method based on extraction and alkylation of butyltins with sodium tetraethylborate was used to quantitatively assess the fate of these analytes in solutions and sediments following exposure to gamma-irradiation. The effects of a 2.5 Mrad sterilization dose on three butyltin species in both methanolic calibration solutions and in sediment(More)
This work explores the performance of laser ablation-inductively coupled plasma mass spectrometry using different types of single-collector devices (sector field and time-of-flight instrumentation) for lead isotopic analysis of bronze coins, minted in the ancient city of Bilbilis. The aim of the study was achieving sufficient discrimination power to reveal(More)
Total mercury in biological samples was determined by flow injection (FI) cold vapour atomic absorption spectrometry (CVAAS) following tissue solubilization with formic acid. A mixture of potassium bromide and potassium bromate was used to decompose organomercury compounds prior to their reduction with sodium borohydride. A gold amalgam system was used to(More)
A method for the determination of U and Th at sub-ppt levels in high-purity Pb samples using extraction chromatography with ICPMS detection is described. Following acid digestion, uranium and thorium are separated from the lead matrix using UTEVA resin. Sorption and elution procedures were optimized, the potential reusability of the chromatographic resin(More)
A rapid and simple on-line method is described for the preconcentration of Mn, Co, Ni, Cu, Zn, Cd and Pb from sea water using 8-hydroxyquinoline immobilized onto silicone tubing (Sil-8-HQ) via the Mannich reaction. Recoveries between 35 and 95% and limits of detection in the ppt range were obtained using a 2 m long Sil-8-HQ tube with a sample flow rate of(More)