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融合分子生物学技术与原子吸收光谱对血清中元素铜、铁和锌的化学形态进行研究。用60%乙醇低温(4℃)沉淀血清蛋白的方法将血清中的铜,铁,锌分为结合态和非结合态,原子吸收分光光度计分别测定血清中Cu,Fe和Zn三种元素的总量及非结合态含量,通过减差法求出血清中结合态元素含量,从而建立了Cu,Fe和Zn元素这两种化学形态的分离分析方法,并讨论了有关的实验条件。该方法铜、铁和锌的检出限分别为9·84×10-3μg·mL-1,2·76×10-2μg·mL-1,1·06×10-3μg·mL-1,相对标准偏差为0·30%~2·31%,回收率为95·0%~104·0%。该法已应用于SD大鼠血清中Cu,Fe和Zn三种元素不同化学形态的测量。 相似文献
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移动供热技术的关键在于蓄热材料。针对当前移动供热技术中,相变材料导热系数低、相变温度低、放热不稳定等不足,本文设计开发了一种新型纳米复合蓄热相变材料。研究了纳米铜、纳米锌、纳米铁、纳米镍和纳米铝对赤藻糖醇的蓄热性能影响,运用时间曲线法确定纳米铜作为基材的添加物。采用超声振荡预处理和添加分散剂等方法,发现按1:1添加的油酸与十二烷基硫酸钠二元混合物8 h无沉降。对纳米铜质量分数不同的六个纳米铜赤藻糖醇样本材料性能进行测定,结果表明添加0.4%的纳米铜赤藻糖醇过冷度下降89.5%,潜热值下降0.3%,固态、液态导热系数分别增大2.8倍和3.3倍。 相似文献
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常见金属离子含量的测定及烟草聚类分析研究 总被引:4,自引:0,他引:4
对5个烟叶产区的88个烟草样品, 利用火焰光度法和原子吸收光谱法分别测定其钾和镁、钠、锰、铁和锌的含量,应用模糊c-均值(FCM)聚类分析与系统聚类分析对这些样品分类。结果表明,模糊聚类分析对于烟草产地的判断具有积极的指导意义,其判断的准确性优于系统聚类分析。 相似文献
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采用燃烧法制备了Fe/Mo/MgO催化剂,用化学气相沉积法在1000℃下催化裂解甲烷制得了单壁纳米碳管.实验结果表明,550℃下焙烧的催化剂效果最好,适宜的酸碱性应该是催化剂具有较高活性的原因.用扫描电镜、透射电镜、高分辨透射电镜、热重分析和拉曼光谱等方法对制备的纳米碳管粗产品进行了表征.结果表明,该产物确为高质量单壁纳米碳管,其形态基本都以束状存在,且单壁纳米碳管直径分布较窄(0.85~1.22nm);对反应气氛的考察表明,CH4/N2=50/300为最佳,该气氛下所制得粗产物中单壁碳管的含量接近40%,经稀盐酸室温处理后,碳管含量可达到75%以上. 相似文献
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不同前处理方法对ICP-AES测定枸杞元素含量的影响 总被引:1,自引:0,他引:1
用ICP-AES测定中药材枸杞中锌、铅、锰、铁、铬、镁、钙、铜、钠、钾、镉11种元素。比较了常规湿法消化法、高压消化罐法和微波消解法处理样品对测定结果的影响。研究结果表明,高压消化罐法和微波消解处理样品,精密度和回收率较好。在选定的实验条件下,各元素间互不干扰,可在同一样品液中进行多种元素的分别测定。利用该方法测定其回收率在92.9%—101.0%之间,相对标准偏差在0.72%—2.40%之间。 相似文献
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采用微波消解-火焰原子吸收光谱法对汉中元胡中钾、钙、钠、镁、锌、锰、铜、铁8种金属元素的含量进行测试,测得结果分别为K(2033.97mg/kg)、Ca(600.87mg/kg)、Na(1395.55 mg/kg)、Mg(494.88mg/kg)、Zn(220.36mg/kg)、Mn(107.75mg/kg)、Cu(39.68mg/kg)、Fe(2462.79mg/kg)。相对标准偏差的范围为0.0356%—4.4288%,回收率的范围为96.8%—101.2%。微波消解-火焰原子吸收光谱法是一种简便而又灵敏的测定中草药中微量元素的方法。 相似文献
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Ultrasonic-assisted synthesis of chrysin derivatives linked with 1,2,3-triazoles by 1,3-dipolar cycloaddition reaction 总被引:1,自引:0,他引:1
The 1,3-dipolar cycloaddition reaction between 7-(3-azidopropoxy)-5-hydroxyflavone and phenylacetylene was carried out to investigate the synthesis of 7-(3-(4-phenyl-1,2,3-triazol-1-yl)propoxy)- 5-hydroxyflavone in presence of ultrasound (sono-synthesis) and absence of ultrasound (conventional method) under relatively optimized solvent and catalyst conditions. The reaction rate was notably accelerated with the help of ultrasound irradiation. An experiment was especially carried out for investigating the acceleration mechanism of ultrasound on the cycloaddition. A novel series of chrysin derivatives linked with 1,2,3-triazoles were obtained by the copper(I)-catalyzed 1,3-dipolar Huisgen cycloaddition reaction using t-BuOH/H(2)O (1:1 v/v) as reaction solvents and CuSO(4)·5H(2)O/sodium ascorbate as the catalyst at room temperature in the presence of ultrasound irradiation. Their structures are elucidated by NMR, ESI MS, IR and Elemental analysis. 相似文献
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J. van Beijnum A. A. van der Horst J. W. Geus A. M. van der Kraan 《Hyperfine Interactions》1994,93(1):1777-1782
A special preparation procedure has been developed to provide a very uniform distribution of iron throughout the copper precursor supported on silica. The best performance for hydrogenolysis of methyl acetate has been obtained for a catalyst prepared in a one-step procedure, in which iron(III) and copper(II) were injected together into a suspension of silica at a constant pH level. It is found that the main part of the iron has been incorporated into the formed copper hydrosilicate. After reduction and under reaction conditions, only about 6% of the iron atoms are in the Fe0 state. This Fe0 is expected to be responsible for the enhancement of the catalyst activity in hydrogenation and hydrogenolysis reactions. 相似文献
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纳米氧化铁/膨润土催化剂的制备、表征及复相光降解罗丹明B的研究 总被引:3,自引:0,他引:3
钠基膨润土与羟基铁溶液反应,经过焙烧,制得性能良好的纳米复合型催化剂,结合比表面孔隙分析(BET)、X射线衍射谱(XRD)和高分辨扫描电镜(HRTEM)对催化剂的比表面积、晶相和粒度进行表征。用光度法对该催化剂降解染料罗丹明B进行了研究,详细考察了溶液起始pH值、H2O2浓度、催化剂用量和起始浓度对降解的影响以及催化剂的可重复使用性,紫外-可见光谱对降解过程进行跟踪检测,并对复相光助Fenton过程与均相光助Fenton过程进行了比较。结果表明,复合型催化剂具有很高的比表面积,铁以高催化活性的α-Fe2O3存在于复合催化剂中;在pH 3.0,催化剂浓度为0.3 g·L-1,H2O2浓度为10 mmol·L-1实验条件下,100 mL 2.5×10-5 mol·L-1罗丹明B,紫外光照射4 h后,紫外-可见光谱显示罗丹明B的特征峰消失,其脱色率和CODCr去除率分别为97%和71%,对该催化剂进行处理后,可以重复使用,复相光降解率要远大于均相光降解率。 相似文献
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N. I. Alekseev S. G. Izotova Yu. G. Osipov S. V. Polovtsev K. N. Semenov A. K. Sirotkin N. A. Charykov S. A. Kernozhitskaya 《Technical Physics》2006,51(2):231-235
Carbon nanotubes are prepared by the method of self-propagating high-temperature synthesis for the first time. The initial components for this synthesis are carboniferous materials (soda, limestone, and Teflon) and reducers (magnesium, lithium, and sodium) with addition of a nickel or iron catalyst. The morphology of the nanotubes (straight multiwall nanotubes apparently free of a catalyst, bent nanotubes completely filled with a catalyst, and carbon nanofibers) is similar to that of nanotubes grown by chemical methods. The nanotubes account for 2–4 wt % of the product synthesized. 相似文献
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目的在于建立同时测定食品中铁、铜、钴三种微量元素的新方法。以2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)为显色剂,Triton X-100为增敏剂,采用流动注射-CCD二极管阵列检测-分光光度分析法同时对其进行测定。优化了实验参数,并用偏最小二乘法计算程序解析重叠光谱。结果显示,铁、铜和钴的线性范围分别为0.2~10 μg·mL-1,0.1~5.0 μg·mL-1,0.01~1.0 μg·mL-1,检出限分别为:0.2,0.1,0.01 μg·mL-1,进样频率为45样·h-1。所建方法用于茶叶、芝麻、小米等食品测定时,样品加标回收率分别为铁89.4%~102.3%、铜92.2%~108.0%、钴93.2%~110.8%,相对标准偏差为1.1%~12.1%。对国家一级标准参考物质茶叶和桃叶进行测定(n=8),结果在其给出的保证值范围之内。 相似文献