Hair analysis is used in some branches of alternative medicine as a method of investigation to assist diagnosis. It is very useful when a history of drug use is difficult or impossible to obtain. In this re-search sus...Hair analysis is used in some branches of alternative medicine as a method of investigation to assist diagnosis. It is very useful when a history of drug use is difficult or impossible to obtain. In this re-search suspended droplet liquid phase microextraction (SDLME) coupled with high-performance liquid chromatography and photodiode array detection (HPLC-DAD) was used for preconcentration and analysis of scopolamine in hair samples. Therefore scopolamine was extracted from 2.0 g hair sample incubated in methanol (5 h, 50°C) and adjusted to pH 7.4 with, Na2HPO4–H3PO4 buffer solution (donor phase, P1) into an organic phase (P2) 350 μl n-octanol and then back extracted into a micro drop of aqueous acceptor phase (P3), adjusted at pH 3, with HCL. The extraction time, T1 (from P1 to P2) was 2 min and T2 (from P2 to P3) was 30 min. Optimum instrumental conditions were included;A C18 reverse phase column with water-acetonitrile-methanol (80:10:10) as the mobile phase was used and wavelength for UV detec-tion was 205 nm. The linear range was 10 to 10000 ng●mL–1, enrichment factor, detec-tion limit and relative standard deviation were 77, 0.1 ng●mL–1 and 5.4 respectively.展开更多
Let R be a ring,X a class of R-modules and n≥1 an integer.We intro-duce the concepts of Gorenstein n-X-injective and n-X-flat modules via special finitely presented modules.Besides,we obtain some equivalent propertie...Let R be a ring,X a class of R-modules and n≥1 an integer.We intro-duce the concepts of Gorenstein n-X-injective and n-X-flat modules via special finitely presented modules.Besides,we obtain some equivalent properties of these modules on n-X-coherent rings.Then we investigate the relations among Gorenstein n-X-injective,n-X-flat,injective and fiat modules on X-FC-rings(i.e.,self n-X-injective and n-X-coherent rings).Several known results are generalized to this new context.展开更多
文摘Hair analysis is used in some branches of alternative medicine as a method of investigation to assist diagnosis. It is very useful when a history of drug use is difficult or impossible to obtain. In this re-search suspended droplet liquid phase microextraction (SDLME) coupled with high-performance liquid chromatography and photodiode array detection (HPLC-DAD) was used for preconcentration and analysis of scopolamine in hair samples. Therefore scopolamine was extracted from 2.0 g hair sample incubated in methanol (5 h, 50°C) and adjusted to pH 7.4 with, Na2HPO4–H3PO4 buffer solution (donor phase, P1) into an organic phase (P2) 350 μl n-octanol and then back extracted into a micro drop of aqueous acceptor phase (P3), adjusted at pH 3, with HCL. The extraction time, T1 (from P1 to P2) was 2 min and T2 (from P2 to P3) was 30 min. Optimum instrumental conditions were included;A C18 reverse phase column with water-acetonitrile-methanol (80:10:10) as the mobile phase was used and wavelength for UV detec-tion was 205 nm. The linear range was 10 to 10000 ng●mL–1, enrichment factor, detec-tion limit and relative standard deviation were 77, 0.1 ng●mL–1 and 5.4 respectively.
基金supported by a scholarship from the Graduate Research Assistantships in Developing Countries Program of the Commission for Developing Countries of the International Mathematical Union.
文摘Let R be a ring,X a class of R-modules and n≥1 an integer.We intro-duce the concepts of Gorenstein n-X-injective and n-X-flat modules via special finitely presented modules.Besides,we obtain some equivalent properties of these modules on n-X-coherent rings.Then we investigate the relations among Gorenstein n-X-injective,n-X-flat,injective and fiat modules on X-FC-rings(i.e.,self n-X-injective and n-X-coherent rings).Several known results are generalized to this new context.
