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41.
采用高效液相色谱-电感耦合等离子体质谱法(HPLC-ICP/MS)测定人尿中硒代胱氨酸(SeCys_2)、甲基硒代半胱氨酸(MeSeCys)、亚硒酸盐[Se(Ⅳ)]、硒代蛋氨酸(SeMet)、硒酸盐[Se(Ⅵ)]5种硒形态。样品经超纯水稀释后,采用Hamilton PRP-X100色谱柱(250 mm×4 mm,10μm)分离,以40 mmol/L磷酸氢二铵(含1%甲醇,pH 5)为流动相进行等度洗脱,13 min内可将5种硒形态分离。5种硒形态的线性范围为0~300.0μg/L,相关系数(r)均大于0.999,检出限为0.2~0.5μg/L。除SeCys_2的加标回收率为37.7%~70.4%外,MeSeCys、Se(Ⅳ)、SeMet、Se(Ⅵ)的加标回收率为80.0%~123%;5种硒形态的相对标准偏差(RSD)均不大于7.8%。应用该方法测定实际样品,结果显示人尿中硒形态主要以SeCys_2为主,同时含有少量MeSeCys、SeMet、无机硒及未知含硒化合物。 相似文献
42.
采用原子荧光法测定茶叶中的硒含量,对样品消解温度及仪器条件进行了优化。还原剂为1.0%硼氢化钾–0.5%氢氧化钾溶液,载流液为3%盐酸溶液。在优化条件下,硒的质量浓度在0~20 ng/mL范围内与荧光强度呈良好的线性关系,相关系数r=0.999,检出限为0.8 ng/mL。该法的加标回收率为88.08%~101.39%,测定结果的相对标准偏差为2.03%~4.84%(n=6)。该方法实际操作性强,准确度高,适用于日常检验工作中对批量茶叶中硒含量的测定。 相似文献
43.
The use of 1,2‐diselenolato‐1,2‐dicarba‐closo‐dodecaborane(12) dianions [1,2‐(1,2‐C2B10H10)Se2]2? prepared in situ as the dilithium salt may lead to irreproducible results. This is shown by the straightforward synthesis of silanes using the purified and isolated dianions, in contrast with previous less successful attempts. Thus, the reactions of the dianions with dichlorosilanes afford the five‐membered diselenasila cycles containing the SiMe2 or the SiPh2 units, and with 1,2‐dichloro‐tetramethyldisilane the six‐membered cycle containing the Si2Me4 unit. The latter was studied by X‐ray diffraction, and all products were characterized by multinuclear magnetic resonance (1H, 13C, 29Si, 77Se NMR) in solution. Novel isotope effects were detected in 13C and 77Se NMR spectra. Exchange reactions of the five‐ and six‐membered diselanasila cycles with chlorosilanes were studied. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
44.
Excimer laser‐induced photolysis of gaseous diethyl selenium and diethyl tellurium (C2H5)2M (M = Se, Te) is controlled by cleavage of both M? C bonds, it yields C1–C4 hydrocarbons (ethene as major product) and results in chemical vapour deposition of selenium films and nanosized tellurium powder. The selenium and tellurium properties were characterized by X‐ray photoelectron spectroscopy and Scanning electron Microscopy techniques. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
45.
46.
《Analytical letters》2012,45(10):655-667
Abstract Radiometric and spectrophotometric procedures for selenium analysis have been developed which are based on the formation and separation of the mono-and di-piazseLenols of 3,3′-diaminobenzidine. Analysis of samples, reaction conditions, and sensitivity of the procedures are discussed. 相似文献
47.
《Green Chemistry Letters and Reviews》2013,6(4):420-434
ABSTRACTBiogenic synthesis of bimetallic nanoparticles (gold – AuNp and selenium – SeNp) using inexpensive Tryptophan Enriched Banana Peel Media for the growth of marine isolate (Exiguobacterium aestuarii SBG4 MH185868). The response surface methodology is employed for optimizing production conditions. The surface plasmon resonance band showed λmax at 540?nm (AuNp) and 284?nm (SeNp). FTIR and zeta potential analysis confirmed the stability, whereas XRD spectra revealed the nature of nanoparticles obtained at optimum conditions. SEM micrographs showed nanospheres of the following size: AuN, 30?±?5 nm and SeNp, 50?±?5 nm. Biocompatibility of Np evaluated by the hemolytic activity showed <20% hemolysis even at highest concentrations (100?µg/ml). AuNp showed the least cytotoxicity, whereas SeNp showed considerable cytotoxicity against the breast cancer cell lines MCF – 7 and MDA-MB-231. Hence, we utilized the environment-friendly growth media for the controlled synthesis of dual Np using single bacterial strain involving feasible steps in downstream processing. 相似文献
48.
Uwe Herzog Uwe Böhme Gerd Rheinwald 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):281-286
The reactions of Me2MCl2 (M = Si, Ge, Sn), Si2Me4Cl2, Si2Me2Cl3, Si2Me2Cl4 and CH2(SiCl2Me)2, and suitable mixtures thereof, with H2S / NEt3 and Li2E (E = Se, Te) have been investigated and lead to a variety of new group 14 chalcogenide systems. 相似文献
49.
Stephen Brand John Milton Martin F. Jones Christopher M. Rayner 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):367-368
A new method for the synthesis of cyclic and acyclic optically active S,O-acetals is reported, along with subsequent stereocontrolled transformations, culminating in a synthesis of the important antiviral nucleoside Lamivudine. 相似文献
50.
H. R. Prakash Naik H. S. Bhojya Naik T. R. Ravikumar Naik M. Raghavendra T. Aravinda D. S. Lamani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):460-470
The synthesis of quinoline-substituted phenylquinazolinones containing sulfur and selenium is described. These molecules were isolated from a series of reactions of 2-phenyl-4H-3,1-benzoxazin-4-one with 2-chloro, 2-thieno, and 2-selenoquinoline-3-carbaldehyde hydrazones. The structure of the isolated compounds has been elucidated on the basis of IR, 1 H NMR, mass spectral, and elemental analysis data. 相似文献