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S N Willie

Publications and source records attributed to S N Willie.

4 recordsLinked to original sources
PubMed2001

What's new with the NRC certified reference material program.

The environmental CRMs currently available from NRC Ottawa comprise four natural waters for trace elements, four biological tissues for trace elements and methylmercury, three marine sediments for major and trace elements (one sediment has certified values for butyltins) and one fish tissue for organochlorines (PCBs, dioxins). Although significant effort has been expended to maintain this suite of materials, several new initiatives have also recently been completed or are in progress. The certified value for arsenobetaine in Dogfish Muscle CRM DORM-2 has been established. The certification approaches, as well as the studies to determine extraction efficiency of this organoarsenic compound, are presented. A stability study has been completed for Hg in a natural water sample and plans are underway for production of a CRM. Assessment of micronutrient stability in seawater for the purposes of CRM production is continuing and progress on this initiative is discussed.

Animals↗
PubMed1998

Determination of total mercury in biological tissues by flow injection cold vapour generation atomic absorption spectrometry following tetramethylammonium hydroxide digestion.

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 present in samples was determined by flow injection cold vapour atomic absorption spectrometry after reduction to elemental mercury vapour using NaBH4. A sample throughput of 100 measurements per hour was achieved after a 30 min dissolution with TMAH. The relative standard deviation for 20 micrograms l-1 Hg was 1.3% (n = 11) and the limit of detection was 0.1 microgram l-1 (3 sigma). The proposed method was validated by the analysis of a suite of certified marine biological reference materials, DORM-2 (dogfish muscle), DOLT-2 (dogfish liver) and TORT-2 (lobster hepatopancreas), with calibration against simple HgII standards.

Flow Injection Analysis↗