Iron(II) Sulphate (Fricke Solution) Oxidation Yields for 8·9 and 13·6keV X-rays from Synchrotron Radiation

The oxidation yields (G) for 8.86 and 13.55 keV X-rays produced by synchrotron radiation were measured using an iron(II) sulphate (Fricke) solution. Monoenergetic X-rays were produced using a silicon crystal monochromator. The X-rays were absorbed in 0.4 M sulphuric acid-iron(II) sulphate solution and FeIII ion yields were measured and corrected for escape fractions resulting from scattering using Monte Carlo calculations. Doses in the solution were determined using a thin window, parallel plate chamber calibrated against a primary standard free-air chamber at the Electrotechnical Laboratory (Osaka, Japan). Yields (G) of 1.50 +/- 0.06 and 1.43 +/- 0.06 mumol J-1 were obtained for 8.86 and 13.55 keV X-rays respectively.

Detection of Pb-LIII edge XANES spectra of urban atmospheric particles combined with simple acid extraction

Pb-LIII edge XANES spectra of atmospheric particles are directly obtained by fluorescent XAFS spectroscopy using a 19-element solid state detector (SSD). Particulate sample was collected on a quartz fiber filter using a high-volume air sampler, and the filter was cut into small pieces (25x25 mm). Then, surface layer of the filter piece was scaled and accumulated in order to enhance the particle density per filter unit. Use of 10 pieces of the surface layer enables the measurement of Pb-LIII edge XANES spectra on beamline BL01B1 at SPring-8, Hyogo, Japan. The shape of the Pb-LIII edge XANES spectra of the particulate sample is similar to the shapes of the spectra for PbS, PbCO(3), PbSO(4) and/or PbCl(2). Additionally, the filter sample is also divided into water-soluble, 0.1 M HCl-extractable, and residual fractions of Pb compounds by a simple acid extraction procedure. We discuss the possibility of Pb speciation in the particulate samples with combination of highly sensitive XANES spectroscopy and simple acid extraction.