原子荧光仪测试岩石矿物中硒元素试验研究

探讨了原子荧光仪测试岩石矿物中硒元素试验研究。运用原子荧光仪测试岩石矿物中硒元素,结果显示：原子荧光仪测试岩石矿物中方法硒元素的回收率、相对标准偏差、方法检出限分别为98.2%-103.0%、0.95%-5.80%、3.5×10^-11g/m L。原子荧光仪方法测试岩石矿物中硒元素具有较为快捷的速度、较高的灵敏度,且简便易行等,值得推广。     

富硒处理对绿豆GSH-Px活性及GSH含量的影响

谷胱甘肽过氧化物酶(GSH-Px),最早是在动物体内发现的一种含硒酶,近年来在许多植物中也发现了该酶的存在,并发现适当浓度的外源硒能提高GSH-Px的活性.本文以绿豆为实验材料,用NaSe2O3 作为硒源,对绿豆进行富硒处理,研究适当浓度的NaSe2O3对绿豆GSH-Px活性及绿豆中谷胱甘肽(GSH)含量的影响.结果显示:富硒处理可以促进绿豆GSH-Px的合成;无论是浸泡过程还是萌芽阶段,经富硒处理的绿豆其GSH-Px的活性都比对照样高;特别是在富硒处理5 h后,绿豆GSH-Px活性显著增加,比对照提高了59.38 %;而绿豆中GSH的含量则是先下降,后升高.     

利用富硒双孢菇粉提升酱油有机硒含量和改善酱油风味

该研究利用临期和损伤富硒双孢菇制备富硒双孢菇粉,以其替代15%质量分数的面粉,按照高盐稀态工艺生产富硒酱油（样品酱油）。结果显示,样品酱油总硒和有机硒含量分别达到134.65和122.53μg/kg,比对照酱油提高5.70倍和5.85倍,有机硒转化率为91.00%,符合富硒酱油标准。理化分析结果表明样品酱油总氮、氨基酸态氮和无盐固形物含量为1.72、1.03和22.56 g/100 mL,比对照酱油提高9.55%、19.77%和5.13%。此外,样品酱油蘑菇香、麦芽香、醇香和果香香气强度比对照酱油提高了5 837.17%、15.62%、20.15%和15.88%。添加富硒双孢菇粉显著提高了大曲和酱醪中蛋白酶酶活,这是富硒双孢菇粉提高酱油滋味物质含量的原因。富硒双孢菇粉中的1-辛烯-3-酮、1-辛烯-3-醇、3-辛醇和3-辛酮赋予了样品酱油蘑菇香。此外,富硒双孢菇粉促进了酱醪中产香微生物的繁殖,进而提高了样品酱油中麦芽香、醇香和果香香气强度。该研究利用临期和损伤富硒双孢菇开发了一种风味良好的富硒酱油,可为双孢菇和酱油生产企业提高产品附加值提供技术参考。     

原子荧光光谱法测定茶叶中微量硒的研究

采用原子荧光光谱法对茶叶中硒的含量进行了分析,用巯基棉富集和硫脲抗坏血酸掩蔽Pb2 、Cu2 、Ag 的干扰.讨论并确定了最佳测定条件,硒的检出限为0.57 ng·mL-1,线性范围为0.00～100.00 ng·mL-1,回收率为99.0%～106.3%,相对标准偏差小于1.71 %.     

高效液相色谱-电感耦合等离子体质谱法同时测定植物性富硒食品中7种硒元素形态的含量

目的 考察微波辅助下酶解法的提取效果, 基于动态反应池(dynamic reaction cell, DRC), 建立高效液相色谱-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry, HPLC-ICPMS)同时测定植物性富硒食品中7种硒元素(硒酸根、亚硒酸根、硒代胱氨酸、L-硒甲基硒代半胱氨酸、L-硒代蛋氨酸、甲基亚硒酸、硒代乙硫氨酸)形态的含量。方法 样品经微波辅助胰蛋白酶酶解, 高速离心后取上清液过水相滤膜。采用HPLC-ICPMS仪, 以甲烷为反应气体DRC模式消除质谱干扰, 内标校正, 以外标法进行定量分析。优化色谱和质谱条件, 从酶的种类、酶的用量、萃取温度、萃取时间、加标回收率等方面考察前处理方法对待测物的提取效果。结果 7种目标物在0.5~100 μg/L范围内呈良好线性关系, 相关系数r均大于0.9998, 平均回收率为91.45%~102.75%, 检出限为0.10~0.30 μg/kg, 定量限为0.30~0.90 μg/kg, 日间日内精密度(n=6)分别小于5%和9%。结论 该方法准确、灵敏, 适用于食品中7种硒元素形态的同时检测。     

生物体内硒蛋白的计算机识别方法

硒是人体必需的微量元素,在人体内主要形成硒蛋白。硒蛋白的计算机识别,不仅能预测生物体中硒的形态,而且可为硒的生化性质研究提供理论基础,以阐明硒的生物功能。本文以斑马鱼为研究对象,结合已有生物分析软件,采用PERL语言编程,建立了计算机识别硒蛋白的新方法。它根据硒蛋白基因的判断标准、以目前公布的不同物种的基因组注释信息为基础,将以TGA码终止的基因的再分析、3′-UTR区域中硒代半胱氨酸插入序列(SECIS)结构的检索、同源相似基因中硒代半胱氨酸/半胱氨酸的比对,以及硒蛋白基因编码区的识别等步骤,从已注释的基因组中用计算机寻找和鉴定硒蛋白的形态。当前,已有一些识别硒蛋白的方法,但只能识别专一物种,而本文提出的方法,克服了该缺陷,而且对计算机运算速度和容量无苛刻要求,尤其是发现不同物种新硒蛋白方面有优势。本方法普遍适用于不同物种基因组中,硒蛋白的计算机预测与识别。     

New Formulation of a Methylseleno-Aspirin Analog with Anticancer Activity Towards Colon Cancer

Aspirin (ASA) has attracted wide interest of numerous scientists worldwide thanks to its chemopreventive and chemotherapeutic effects, particularly in colorectal cancer (CRC). Incorporation of selenium (Se) atom into ASA has greatly increased their anti-tumoral efficacy in CRC compared with the organic counterparts without the Se functionality, such as the promising antitumoral methylseleno-ASA analog (1a). Nevertheless, the efficacy of compound 1a in cancer cells is compromised due to its poor solubility and volatile nature. Thus, 1a has been formulated with native α-, β- and γ-cyclodextrin (CD), a modified β-CD (hydroxypropyl β-CD, HP-β-CD) and Pluronic F127, all of them non-toxic, biodegradable and FDA approved. Water solubility of 1a is enhanced with β- and HP- β-CDs and Pluronic F127. Compound 1a forms inclusion complexes with the CDs and was incorporated in the hydrophobic core of the F127 micelles. Herein, we evaluated the cytotoxic potential of 1a, alone or formulated with β- and HP- β-CDs or Pluronic F127, against CRC cells. Remarkably, 1a formulations demonstrated more sustained antitumoral activity toward CRC cells. Hence, β-CD, HP-β-CD and Pluronic F127 might be excellent vehicles to improve pharmacological properties of organoselenium compounds with solubility issues and volatile nature.     

Carbon supported Ru–Se as methanol tolerant catalysts for DMFC cathodes. Part I: preparation and characterization of catalysts

Carbon supported Ru _x Se _y O _z catalysts were prepared from Ru₃(CO)₁₂ and RuCl₃ · xH₂O as ruthenium precursors and H₂SeO₃ and SeCl₄ as the selenium sources. Highly active catalysts for the oxygen reduction reaction (ORR) in direct methanol fuel cells (DMFC) were obtained via a multi-step preparation procedure consisting of a CO₂-activation of the carbon support prior to the preparation of a highly disperse Ru particles catalyst powder that is subsequently modified by Se. Ultimately, an excess of Se was removed during a final thermal annealing step at 800 °C under forming gas atmosphere. The morphology of the catalysts was analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD), which shows that the catalysts consist of crystalline Ru-particles with sizes ranging from 2 to 4 nm exhibiting a good dispersion over the carbonaceous support. The corresponding catalytic activity in the process of oxygen reduction was analyzed by cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements. The nature of the carbon support used for the preparation of RuSe cathode catalysts is of significant importance for the activity of the final materials. Catalysts supported on CO₂-activated Black Pearls 2000 gave the highest ORR-activity. Se stabilizes the Ru-particles against bulk oxidation and actively contributes to the catalytic activity. An exceptional property of the carbon supported Ru-particles modified with Se is their resistance to coalescence up to temperatures of 800 °C under inert or reducing conditions. Additional effects of Se-modification are the enhanced stability towards electrochemical oxidation of Ru and a lowering of the H₂O₂ formation in the ORR.     

无铅易切削硒铋黄铜的研究

介绍了无铅易切削硒铋黄铜的制备工艺，于中频感应炉中制备了无铅易切削硒铋黄铜铸锭，并对其组织和力学性能以及抗腐蚀性进行了测定。结果表明，铋以铜铋中间合金形式在1200℃加入时，铋均匀分布在铜合金中。该工艺制备的无铅易切削硒铋黄铜具有较HPb59-1好的力学性能、机加工性能和抗脱锌腐蚀性能。通过物相与组织形貌分析，解释了铋改善铜合金切削性能的机理。     

水泥窑协同处置固废中硒元素的测定方法探讨

本文使用原子荧光光谱仪对水泥窑协同处置固废中的硒元素进行了测定方法开发工作。方法中采用了倒王水沸水浴对固体废弃物进行消解溶样,以10%盐酸作为载流液,0.4%氢氧化钾和1.2%硼氢化钾作为还原剂,铁氰化钾作为掩蔽剂,以消除各种离子的干扰。优化了原子荧光光谱仪的测定条件,对标准样品和固废样品进行了检测。方法检出限为0.04μg/L,相对标准偏差为3.0%~10.1%。固废和污泥中加标回收率为82.8%~102.5%。