微滴溶剂萃取/低温电热蒸发ICP-AES联用新技术用于超痕量元素分析

Liu等[1] 首先提出了微滴溶剂萃取的新概念 ,并设计了微滴萃取装置 .Jeannot等[2 ] 用微升级的正辛烷对蛋白质溶液中键合 /未键合的黄体酮进行了萃取分离 .随后 ,文献 [3 ]报道了富集倍数超过 1 0 0 0的连续流动微滴溶剂萃取技术 .针对生物样品量少且昂贵这一情况 ,Kellert等 [4 ]提出纳升级溶剂超微滴萃取技术 .电热蒸发 (ETV)作为一种有效的微量试样 (固体、液体 )引入技术备受人们的关注[5,6 ] .微滴萃取技术与高灵敏度的 ETV-ICP-AES/ MS联用必将在微量试样的超痕量分析 /形态分析中发挥重要作用 .我们基于微滴溶剂萃取原理 ,设…     

Determination of Trace Elements in Super Alloy by ICP-MS

 A method is described for determination of 14 trace elements in super alloy certified reference material. Inconel 718 by ICP-MS. The interferences were investigated in detail. By using appropriate settings of the operational parameters and correcting interferences the elements without interference free isotopes were also analyzed. Non-spectral interference to the analytes was studied. No matrix separation or any other sample pretreatment but acid dissolution was made. 14 trace elements (B, Sc, Ga, Ge, In, Sn, Sb, Te, Hf, Ag, Ce, Tl, Pb and Bi) were analyzed by matrix matched standard solution calibration and using Rh as internal standard. Good agreement was achieved between the found levels and the certified values for most of the elements. The RSD (n = 4) of the determination values of Ce was lower than 20%, and RSD of the other 13 elements was lower than 10%. Received July 21, 2000. Revision May 29, 2001.     

Performance of ICP-MS with Hexapole Collision Cell and Application for Determination of Trace Elements in Bio-Assays

 The application of a hexapole collision cell in quadrupole based inductively coupled plasma mass spectrometry (HEX-ICP-QMS) was studied systematically in order to characterize the performance of this approach for multielement analysis. Additionally, the performance of different solution introduction systems was studied for use with HEX-ICP-QMS (Platform, Micromass Ltd., Manchester, UK) and the developed methods were applied in the multielement analysis of biological tissue. A significant improvement in detection limits was achieved for ions affected by interferences with argon ions and argon-based molecular ions due to the removal of Ar⁺ and ArX⁺ ions (X = H, C, N, O, Ar) as well as for heavy elements (m > 100 u) due to better ion transmission through the hexapole ion guide. Metal oxide ion formation was reduced by up to ten times by the application of hexapole bias potential. Accuracy of the HEX-ICP-QMS measurements was assessed by analyzing standard reference material SRM 1566a Oyster Tissue and comparison with neutron activation analysis. Good agreement of measured trace element concentrations with certified values was found for most elements. Received December 7, 2000. Revision April 3, 2001.     

关于算子迹的Bellman不等式

本文将矩阵中关于半正定 Hermite矩阵的 Bellman不等tr(AB) k tr(Ak Bk) ,k =1 ,2 ,…推广到 Hilbert空间 ,得到关于正的迹算子的相应不等式     

液膜技术在化学化工分离中的应用研究进展

介绍了液膜技术原理,讨论了液膜分离用于医药化工、贵金属提取、痕量分析及废水处理的研究进展。     

毛细管电泳法检测蜂蜜中残留的抗生素

 用毛细管电泳法对 5种常用的抗生素四环素 (TC) ,土霉素 (OTC) ,多西环素 (DOC) ,金霉素 (CTC)和氯霉素 (CP)进行了分离。研究了电泳缓冲液的 pH、不同有机试剂添加剂、温度等因素对抗生素分离的影响。实验结果表明 ,体积分数为 4%的N 甲基吗啡啉的加入可大大改善分离效果。在各自相应的浓度范围内 ,峰面积和样品浓度之间呈现良好的线性关系 ,重现性好。氯霉素的检测极限为 10 μg/L ,四环素、土霉素、多西环素为 2 0 μg/L ,金霉素为 40 μg/L(信噪比 >5 )。该方法成功地应用于蜂蜜中残留抗生素的测定 ,具有操作简单、快速方便、灵敏度及自动化程度高。     

氦离子化气相色谱仪的实验条件及其应用

论述了氦离子化气相色谱仪的原理、构造以及与该仪器用密切相关的多种影响因素。同时还介绍了该仪器的广泛应用以及在分析测试中的一些技巧,尤其是在气体工业和半导体制造工业所用化学品的分析。     

圈养野生动物毛发微量元素研究

采用电感耦合等离子体发向射光谱法研究了三十种圈养野生动物毛发中12种元素的含量。对微量元素在野生动物生命过程中的作用进行了探讨。     

微量元素铜、铁、锰、锗与自由基

自由基所造成的脂质过氧化损伤与许多病理过程有关,但体内存在消除氧自由基的酶等抗自由基物质,微量元素是酶的结构成分和活性中心,铜、铁、锰、猪等微量元素对自由基的代谢产生影响。     

胃癌与微量元素相关性研究

报道了胃癌患者发中微量元素的变化信息。认为胃癌患者较正常人Zn、Zn/Cu、Mg、Ca均呈显著降低 (P <0 0 5 ) ,胃癌与胃溃疡相比 ,Zn、Zn/Cu、Mg均呈显著降低 (P <0 0 5 )。因此 ,发中微量元素化学信息的变化 ,可作为本地区胃癌的辅助诊断和胃癌与胃溃疡的区别及辅助诊断的依据之一。