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961.
安徽24种常用中药材中铅的含量分析 总被引:1,自引:1,他引:0
采用原子吸收分光光度法(AAS)测定了安徽省24种常用中药材中铅的含量。结果表明,所测中药材中铅的含量与其药用部位有关:由高到低顺序为:叶类中药材,树皮类中药材,花类中药材,根类中药材,果实种子类中药材;叶类中药材最容易受到环境铅的污染,应引起重视。 相似文献
962.
Miniaturized potentiometric membrane sensors for quinine incorporated with molecular imprinted polymer (MIP) were synthesized and implemented. Planar PVC based polymeric membrane sensors containing quinine‐methacrylic and/or acrylic acid‐ethylene glycol methacrylate were dispensed into anisotropically etched wells on polyimide wafers. The determination of quinine was carried out in acidic solution at pH 6, where positively charged species predominated prevalently. The suggested miniaturized planner sensors exhibited marked selectivity, sensitivity, long‐term stability and reproducibility. At their optimum conditions, the sensors displayed wide concentration ranges of 4.0×10?6–1.0×10?2mol L?1 and 1.0×10?5–1.0×10?2 mol L?1 with slopes of about 61.3–55.7 mV decade?1; respectively. Sensors exhibit detection limits of 1.2×10?6 and 8.2×10?6 mol L?1 upon the use of methacrylic and acrylic acid monomers in the imprinted polymer, respectively. Validation of the assay method according to the quality assurance standards (range, within‐day repeatability, between‐day variability, standard deviation, accuracy, and good performance characteristics) which could assure good reliable novel sensors for quinine estimation was justified. Application of the proposed flow‐through assay method for routine determination of quinine in soft drinks was assayed and the results compared favorably with data obtained by the standard fluorimetric method. 相似文献
963.
Rosa Olivé‐Monllau Mireia Baeza Jordi Bartrolí Francisco Céspedes 《Electroanalysis》2009,21(8):931-938
A novel amperometric sensor based on a rigid graphite‐epoxy composite of which composition is near to the percolation is reported. The electrochemical response of the novel transducer material was evaluated in terms of reproducibility of the fabrication process and reproducibility and repeatability of the analytical signal. The signal to noise ratio was improved. atomic force microscopy (AFM) technique was used to obtain qualitatively information. Amperometric detection of chlorine in water was carried on at a set potential of ?250 mV vs. Ag/AgCl. The developed flow injection analysis (FIA) system responded linearly to chlorine concentration between 0.15 mg L?1 and 4 mg L?1with a sensitivity of ?0.20 μA L mg?1. The proposed system was applied to real samples from swimming‐pool water. No significant difference was observed regarding the standard method. 相似文献
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966.
称取0.5 g试样,用盐酸、硝酸、硫酸分解,铅以硫酸铅沉淀的形式分离.以过硫酸铵为氧化剂,氨性溶液中沉淀分离铁、锰等共存元素,加氟化物掩蔽铝、硫脲掩蔽铜,调节溶液pH=5.0~6.0,加入碘化钾消除镉的干扰,以二甲酚橙为指示剂,用ED TA标准溶液滴定.将沉淀物重新溶解,用原子吸收光谱法测定其中的锌量.在0.2% ~1... 相似文献