Evaporation experiments were undertaken to determine the volatility of parts-per-million concentrations of boron in water and dilute HCl in the presence and absence of equimolar mannitol and/or cesium. Multiple 10 mL aliquots prepared identically were evaporated to various extents or just to dryness and heated 10-20 min after reaching dryness under filtered air at 60 °C. Boron was only retained quantitatively in water during evaporation and after reaching dryness in the presence of equimolar mannitol and cesium. Boron was retained quantitatively in dilute HCl solution during evaporation, without mannitol or cesium. But it could be retained when the dilute HCl just reached dryness and thereafter only in the presence of equimolar mannitol. Isotopic measurements of the evaporating solutions and residues indicate that the heavier isotope, 11 B, is preferentially lost from the nearneutral and acidic solutions examined. The results are pertinent for procedures requiring preconcentration of boron.
We have developed and prepared a new type of substrate by impregnating silica with silver for surfaceenhanced Raman scattering (SERS). The effects of several experimental conditions of preparation, including the drying temperature, the molar ratio of Ag to Si, the calcination time and the calcination temperature, were investigated and varied to give a better surface enhancement efficiency of the substrate. X-ray diffraction and transmission electron microscopy were used to measure the relative abundance of silver metal and the size of silver particles in the substrates. The results provided useful information that would be helpful in explaining the surface-enhanced performance of silica-supported silver substrates prepared under different conditions. The SERS spectra of several organic dyes were used to demonstrate the performance of the silver-silica substrate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.