This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This...This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.展开更多
Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal pla...Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal plain of the Laizhou Bay in northeast China,was used,of which the top 54 m containing all marine facies was focused,to test the feasibility of colorimetry as a climate indi-cator using visible light reflectance spectra and L＊a＊b＊measurement results. The results show a good correction between lightness and calcium carbonate content in marine-terrigenous deposits;therefore,these deposits can be used as a proxy to study climate changes. Factor-analysis on the first derivative values of the raw visible light reflectance spectra produced three principal factors corresponding to goethite,organic matter,and hematite. Down hole variations in the three fac-tor scores,lightness,calcium carbonate content,and grain size were quite consistent. Moreover,high lightness and low factor scores in goethite,hematite,and organics indicated glacial regression deposits,while low lightness and high factor scores in goethite,hematite,and organics indicated interglacial transgression deposits.展开更多
文摘This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.
基金The National Natural Science Foundation of China under contract No. 40602018the Chinese Offshore Investigation and Assessment ("908" Program) under contract No. 908-01-ZH2the Marine Welfare Research Project under contract No. 200805063
文摘Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal plain of the Laizhou Bay in northeast China,was used,of which the top 54 m containing all marine facies was focused,to test the feasibility of colorimetry as a climate indi-cator using visible light reflectance spectra and L＊a＊b＊measurement results. The results show a good correction between lightness and calcium carbonate content in marine-terrigenous deposits;therefore,these deposits can be used as a proxy to study climate changes. Factor-analysis on the first derivative values of the raw visible light reflectance spectra produced three principal factors corresponding to goethite,organic matter,and hematite. Down hole variations in the three fac-tor scores,lightness,calcium carbonate content,and grain size were quite consistent. Moreover,high lightness and low factor scores in goethite,hematite,and organics indicated glacial regression deposits,while low lightness and high factor scores in goethite,hematite,and organics indicated interglacial transgression deposits.
