Selenium fractionation and cycling in the intertidal zone of the Carquinez Strait. Quarterly progress report, January 1996--March 1996

Selenium fractionation and cycling in the intertidal zone of the Carquinez Strait. Quarterly progress report, October 1995--December 1995

“…The potential exists for fractionation of the isotopes if reduction of the selenium ._ is not complete. If this is found to be a problem, the *%e + 74Se spike (Zawislanski et.-al., 1995) can be added to the sample to compensate.…”

“…Velinsky and Cutter (1990) did not observe increased solubilization of non-target Se fractions due to sonication, but did report that sulfite does solubilize organic and inorganic Se species (Se IV and Se VI). Sequential extraction has been shown to remove the bulk of the organic, selenite, and selenate species (Zawislanski et al, 1995). Therefore, interference from other residual Se species in the elemental Se extraction should be minimal in comparison to elemental Se concentrations.…”

Selenium fractionation and cycling in the intertidal zone of the Carquinez Strait. Annual report, October 1, 1995--December 31,1996

“…Field and laboratory research conducted in 1994 and 1995 was described i n Zawislanski et al (1995) and the resultant preliminary conclusions are summarizeld below. Preliminary conclusions reached at that time were used to guide the design of research activities in 1996.…”

“…The sites needed to be downstream of the local refineries. Both sites are described in greater detail in the 1995 Annual Report (Zawislanski et al, 1995). That description is summarized below.…”

“…Although this extraction procedure has been shown to It= quite effective in removing elemental Se (Zawislanski et al, 1995), it should still be considered operationally-defined until more objective methods, such as x-ray absorption spectroscopy, are applied. , while Se oxidation is sluggish (Zawislanski and Zavarin, 1996).…”