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采用高效液相色谱法同时测定了口服液中的咖啡酸和阿魏酸含量,用Shim-pack VP-ODS柱(150 mm×4.6 mm,0.3μm),流动相:乙腈-3%的冰醋酸水溶液(体积比为11∶89),流速:1.0 mL/min,检测波长:321 nm.咖啡酸和阿魏酸的浓度与峰面积呈良好的线性关系,其线性范围分别为0.126~63.0 μg/mL(r=0.999 7)和0.120~24.0 μg/mL(r=0.999 9),平均回收率(n=3)分别为100.7%和99.9%,相对标准偏差(RSD)分别为2.11%和2.12%,检出限分别为42 ng/mL和43 ng/mL,样品中咖啡酸和阿魏酸的平均含量分别为3.26μg/mL和2.36μg/mL.Abstract: An HPLC method was established for the simultaneous determination of ferulic acid and caffeic acid in oral liquid. The Shim-pack VP-ODS column (150 mm×4.6 mm, 0.3 μm) was used with a mobile were detected at a wavelength of 321 nm. The flow rate was 1.0 mL/min and the injection volume was 20 μL. The calibration curve was linear in the range of 0. 126-63.0 μg/mL (r=0. 999 7) for caffeic acid and 0. 120-24.0 μg/mL (r=0. 999 9) for ferulic acid. The average recovery (n=3) was 100.7% with RSD 2. 11% for caffeic acid and was 99.9% with RSD 2.12% for ferulic acid. The detection limit was 42 ng/mL for caffeic acid and 43 ng/mL for ferulic acid. The average content of the samples was 3. 26 μg/mL for caffeic acid and 2.36 μg/mL for ferulic acid. 相似文献
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在pH=4.8的Britton-Robinson(B-R)缓冲溶液中,用循环伏安法研究了甲苯胺蓝(TB)与硫酸软骨素(cs)的相互作用.在最佳实验条件下,TB与CS通过静电作用形成复合物,导致溶液的氧化峰电流和还原峰电流均明显降低,其峰电流差值(△ip)与CS的浓度成正比,据此建立了一种测定CS浓度的新方法,测定的线性范围为1.0~21.0μg/mL,相关系数R=0.9981,检测限(3σ)为0.26μg/mL.该法应用于硫酸软骨素针剂的测定,结果满意. 相似文献
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基于肾上腺素在高碘酸钾-鲁米诺碱性体系中的后化学发光反应,结合流动注射技术,建立了测定肾上腺素的流动注射-化学发光(FI(CL)方法.该方法简单、快速、灵敏,线性范围为3.0×10-5~1.2×10-4 g/L(r=0.996 9),检出限为3.0×10-7 g/L(3σ).对5.0×10-5 g/L的肾上腺素标准溶液进行11次平行测定,相对标准偏差为2.0%.将其应用于肾上腺素注射液中肾上腺素含量的测定,结果令人满意.同时,还初步探讨了该化学发光反应的发光机制. 相似文献
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在我国现行教育体系中,英语教学一直有着较大的阻碍。主要原因在于英语教师涉及到母语环境问题,由于学生较少使用英语,导致语言的表达能力和阅读能力无法提升。可以理解为,在初中英语考试中,学生较常出现的问题是在于阅读理解,而不是在于规范化的填空。故此,本文将以英语阅读为主要研究对象,以期能够通过相关问题的研究,提出有效的教学策略。 相似文献
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基于阿魏酸对鲁米诺-铁氰化钾化学发光体系的抑制作用,建立了阿魏酸的流动注射抑制化学发光分析法,在优化的实验条件下,阿魏酸浓度在4.0×10~(-7)~4.0×10~(-6) mol/L之间时,与化学发光强度减小值呈现良好线性关系,检出限为2.4×10~(-7) mol/L,对1.0×10~(-6) mol/L阿魏酸的相对标准偏差为1.4%(n=9),将其应用于复方当归注射液中阿魏酸含量的测定,结果令人满意.此外,结合化学发光光谱和紫外吸收光谱对抑制化学发光机理进行了初步探讨.Abstract: Based on the fact that the chemiluminescence intensity of the luminol- K3Fe(CN)6 system is inhibited in the presence of ferulic acid, a novel flow injection chemiluminescence inhibition method for the determination of ferulic acid was developed. Under the optimum conditions, the decrease in chemiluminescence intensity was linear with ferulic acid concentration in the range from 4. 0 × 10~(-7) to 4.0 × 10~(-6) mol/L.The detection limit was 2.4 × 10~(-7) mol/L and the relative standard deviation was 1.4% for 1.0 × 10~(-6) mol/L ferulic acid (n=9). When applied to the determination of ferulic acid in Fufang Danggui Injection samples, this method gave satisfactory results. Furthermore, combining the chemiluminescence spectra with the UV absorption spectra, the paper presents a brief discussion of their chemiluminescence inhibition mechanisms. 相似文献
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研究了基于邻苯二胺聚合膜的纳米金自组装NADH修饰玻碳电极的制备,并探讨了肾上腺素在此修饰电极上的电化学行为,在pH=7.2的磷酸盐缓冲液中,肾上腺素在该修饰电极上产生一个灵敏的氧化峰,峰电流与肾上腺素浓度在3.0×10-6~5.0×10-5 mol/L范围内呈良好的线性关系,检出限为3.15×10-7 mol/L.该方法可用于盐酸肾上腺素注射液中肾上腺素的检测. 相似文献
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采用自组装技术、交流阻抗法研究了对巯基苯硼酸对铝在3.5% NaCl溶液中的腐蚀行为.实验表明,随着对巯基苯硼酸浓度的变化和组装时间的不同缓蚀效率有所不同.当对巯基苯硼酸浓度为3.2×10~(-3) mol/L,组装时间为12 h时腐蚀电流最小,缓蚀效率最高,达98%以上.Abstract: The corrosion behavior of aluminum with 4-mercaptophenyl-boronic acid in a 3.5% NaCl solution was studied, using the self-assembly technology and EIS (electrochemical impedance spectroscopy).The efficiency of corrosion inhibition was found to vary with the concentration of 4-mercaptophenyl-boronic acid and the assembly time. A 4-mercaptophenyl-boronic acid concentration of 3.2×10~(-3) mol/L in combination with an assembly time of 12h was the optimum condition, under which the corrosion current was the smallest and efficiency was the highest (98%). 相似文献