BaFe12O19 powders with nanocrystaUine sizes were produced by sol-gel auto-combustion method. The precursors were prepared under the molar ratios of citric acid to the metal nitrate of 0.5, 1.0 and 1.5. Appropriate eth...BaFe12O19 powders with nanocrystaUine sizes were produced by sol-gel auto-combustion method. The precursors were prepared under the molar ratios of citric acid to the metal nitrate of 0.5, 1.0 and 1.5. Appropriate ethylene diamine （C2H8N2） was added in order to adjust pH of 7. The ions distribution of citric acid at different pH explains the effect of citric acid in the starting solution. The XRD patterns of the as-burnt powders and annealing powders show different phases for different citric acid content. In addition, the lattice constants （a, c） derived from X-ray diffraction pattern were changed from 0.58881 nm to 0.58997 nm and 2.32057 nm to 2.32296 nm respectively. The data from VSM indicated that the powder with high citric acid content took on good magnetic properties. Pure single BaFe12O19 of the specific maximum magnetization M（1 T）≈ 49.73 Am^2/kg, the specific remanent magnetization Mr ≈ 30.77 Am^2/kg and the coercive force He≈ 467 kA/m was produced when the molar ratios of citric acid to the metal nitrate was 1.5.展开更多
目的:采用离子色谱法测定枸橼酸芬太尼原料药和注射液中枸橼酸的含量。方法:分析柱为Thermo Dionex Ion Pac^(TM) AS11-HC,流动相为氢氧化钾溶液(梯度洗脱),流速为1.0 m L/min,柱温为35℃,进样量为20μL,检测器为抑制型电导检测器。结果...目的:采用离子色谱法测定枸橼酸芬太尼原料药和注射液中枸橼酸的含量。方法:分析柱为Thermo Dionex Ion Pac^(TM) AS11-HC,流动相为氢氧化钾溶液(梯度洗脱),流速为1.0 m L/min,柱温为35℃,进样量为20μL,检测器为抑制型电导检测器。结果:枸橼酸检测质量浓度线性范围为0.115 7~74.05μg/m L(r=0.999 5);定量限为0.115 0μg/m L,检测限为0.040 0μg/m L;精密度、稳定性、重复性试验的RSD<2.0%;加样回收率为99.6%~101.5%(RSD=0.68%,n=9)。结论:该方法环保、简便,准确度和精密度良好,适用于枸橼酸芬太尼原料药及注射液中枸橼酸的含量测定。展开更多
基金Project supported by the Shanghai Nano-Technology Promotion Center and Science and Technology of Shanghai Municipality (Grant No.O452nm049)
文摘BaFe12O19 powders with nanocrystaUine sizes were produced by sol-gel auto-combustion method. The precursors were prepared under the molar ratios of citric acid to the metal nitrate of 0.5, 1.0 and 1.5. Appropriate ethylene diamine （C2H8N2） was added in order to adjust pH of 7. The ions distribution of citric acid at different pH explains the effect of citric acid in the starting solution. The XRD patterns of the as-burnt powders and annealing powders show different phases for different citric acid content. In addition, the lattice constants （a, c） derived from X-ray diffraction pattern were changed from 0.58881 nm to 0.58997 nm and 2.32057 nm to 2.32296 nm respectively. The data from VSM indicated that the powder with high citric acid content took on good magnetic properties. Pure single BaFe12O19 of the specific maximum magnetization M（1 T）≈ 49.73 Am^2/kg, the specific remanent magnetization Mr ≈ 30.77 Am^2/kg and the coercive force He≈ 467 kA/m was produced when the molar ratios of citric acid to the metal nitrate was 1.5.
