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电感耦合等离子体发射光谱(ICP)检测电生理导管可沥滤物的试验方法研究
本文采用电感耦合等离子体发射光谱法检测电生理导管中四种可沥滤物:硫酸钡,颜料黄53,颜料棕24和二氧化钛的含量。经方法验证,该方法校准曲线线性良好,线性范围达4~6个数量级;检出限极低,小于0.1μg/m L;回收率达到95%~103%;实验室内检测变异系数小于3%。该方法可同步测量多种超低痕量金属元素,大大减少了样品预处理和样品使用量,具有实用性和经济性,值得推广使用。
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The sample preparation of samples containing bovine serum albumin (BSA), e.g., as used in transdermal Franz diffusion cell (FDC) solutions, was evaluated using an analytical quality-by-design (QbD) approach. Traditional precipitation of BSA by adding an equal volume of organic solvent, often successfully used with conventional HPLC-PDA, was found insufficiently robust when novel fused-core HPLC and/or UPLC-MS methods were used. In this study, three factors (acetonitrile (%), formic acid (%) and boiling time (min)) were included in the experimental design to determine an optimal and more suitable sample treatment of BSA-containing FDC solutions. Using a QbD and Derringer desirability (D) approach, combining BSA loss, dilution factor and variability, we constructed an optimal working space with the edge of failure defined as Do0.9. The design space is modelled and is confirmed to have an ACN range of 8373%and FA content of 170.25%.
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A highly selective and stability-indicating HPLC-method, combined with appropriate sample preparation steps, is developed for β-artemether assay and profiling of related impurities, including possible degradants, in a complex powder for oral suspension. Following HPLC conditions allowed the required selectivity: a Prevail organic acid (OA) column (250 mm×4.6 mm, 5μm), flow rate set at 1.5 mL/min combined with a linear gradient (where A ? 25 mM phosphate buffer (pH 2.5), and B ? acetonitrile) from 30% to 75% B in a runtime of 60 min. Quantitative UV-detection was performed at 210 nm. Acetonitrile was applied as extraction solvent for sample preparation. Using acetonitrile-water mixtures as extraction solvent, a compartmental behaviour by a non-solving excipient-bound fraction and an artemether-solubilising free fraction of solvent was demonstrated, making a mobile phase based extraction not a good choice. Method validation showed that the developed HPLC-method is considered to be suitable for its intended regulatory stability-quality characterisation of β-artemether paediatric formulations. Furthermore, LC-MS on references as well as on stability samples was performed allowing identity confirmation of the β-artemether related impurities. MS-fragmentation scheme of β-artemether and its related substances is proposed, explaining the m/z values of the in-source fragments obtained.