ICP-AES测定奥里油中钒、钠和镁

应用 ICP- AES法同时测定奥里油中钒、钠、镁含量。用程序升温法灰化奥里油样品 ,引入大流量的干燥空气除去样品中水分 ,解决了传统灰化法因样品突沸引起的金属元素损失及重复性差的问题     

Exploratory analysis and inductively coupled plasma optical emission spectrometry (ICP OES) applied in the determination of metals in soft drinks

A 2³ factorial design and a CCD (Central Composite Design) were employed to optimize the operational conditions for determining Al, Ba, Ca, Cd, Cr, Cu, K, Mg, Na, Ni, Pb, Sn and Zn in soft drink samples by inductively coupled plasma optical emission spectrometry (ICP OES). Satisfactory parameters of merit were obtained (Plasma stability, linearity, SBR, BEC, LOD and LOQ). The accuracy was evaluated by means of a recovery study. Thirty five soft drink samples were analyzed. The results obtained were used in an exploratory analysis, in which principal component analysis and cluster analysis were applied in order to differentiate the several soft drink classes. Adequate LOQ values were obtained for all elements (0.34 μg L^− 1 for Ca to 88.7 μg L^− 1 for Mg) and the recovery study results ranged between 80 and 100%. Cluster analysis revealed four sample classes characterized by flavor and other characteristics, such as being light, diet, low calorie or regular beverages. A model with 4 PCs was obtained by means of a principal component analysis, which explained 99.8% of the total variance.     

Preconcentration of Rare Earth Elements in Seawater with Chelating Resin Having Fluorinated β‐Diketone Immobilized on Styrene Divinyl Benzene for their Determination by ICP‐OES

An analytical method has been developed for the preconcentration of rare earth elements (REEs) in seawater for their determination by inductively coupled plasma optical emission spectrometry (ICP‐OES). An indigenously synthesized chelating resin was used for the preconcentration of (REEs) which was based on immobilization of fluorinated β‐diketone group on solid support styrene divinyl benzene. Sample solutions (adjusted to optimized pH) were passed through a polyethylene column packed with 250 mg of the resin. Experimental conditions consisting of pH, sample flow rate, sample volume and eluent concentration were optimized. The established method has been applied for the preconcentration of light, medium and heavy REEs in coastal sea water samples for their subsequent determination by (ICP‐OES). Percentage recoveries of La, Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb and Lu were ≥ 95%, a preconcentration factor of 200 times, and relative standard deviations < 5% were achieved.     

Defect structure and optical damage resistance of In:Fe:Cu:LiNbO3 crystals with various [Li]/[Nb] ratios

In:Fe:Cu:LiNbO₃ crystals were grown in air by the Czochralski technique with various [Li]/[Nb] ratios of 0.946, 1.050, 1.200, and 1.380 in melt. Based on the ICP‐AES (inductively coupled plasma atomic emission spectrometry) analyzed results, the chemical formula of the triple‐doped In:Fe:Cu:LiNbO₃ crystals were obtained. It can be seen that the near‐stoichiometric ratio value is between 1.050 and 1.200 for our samples. The optical damage resistance of In:Fe:Cu:LiNbO₃ crystals was characterized by changes in light‐induced birefringence and it increases with the increasing of [Li]/[Nb] ratios. The dependence of the optical damage resistance on the defect structure of In:Fe:Cu:LiNbO₃ crystals is discussed in detail based on the obtained chemical formulas. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Study of phytochelatins and other related thiols as complexing biomolecules of As and Cd in wild type and genetically modified Brassica juncea plants

The accumulation of As and Cd in Brassica juncea plants and the formation of complexes of these elements with bioligands such as glutathione and/or phytochelatins (PCs) is studied. The genetic manipulation of these plants to induce higher As and Cd accumulation has been achieved by overexpressing the genes encoding for gamma-glutamyl cysteine synthetase (gamma-ECS) and glutathione synthetase (GS). These two enzymes are responsible for glutathione (GSH) formation in plants, which is the first step in the production of PCs. The biomass produced in both the wild type and the genetically modified plants, has been evaluated. Additionally, the total Cd and As concentration accumulated in the plant tissues was measured by inductively coupled plasma mass spectrometry (ICP-MS) after extraction. Speciation studies on the extracts were conducted using size exclusion liquid chromatography (SEC) coupled online with ICP-MS to monitor As, Cd and S. For further purification of the As fractions, reversed phase high performance liquid chromatography (RP-HPLC) was used. Structural elucidation of the PCs and other thiols, as well as their complexes with As and Cd, was performed by electrospray-quadrupole-time-of-flight (ESI-Q-TOF). In both the Cd and As exposed plants it was possible to observe the presence of oxidized PC2 ([M + H]+, m/z 538), GS-PC2(-Glu) ([M + H]+, m/z 716) as well as reduced GSH ([M + H]+, m/z 308) and oxidized glutathione (GSSG) ([M + H]+, m/z 613). However, only the GS plants exhibited the presence of As(GS)3 complex ([M + H]+, m/z 994) that was further confirmed by MS/MS. This species is reported for the first time in B. juncea plant tissues.     

Plasma-assisted surface treatment for low-temperature annealed ohmic contact on AlGaN/GaN heterostructure field-effect transistors

In this study, a low-temperature annealed ohmic contact process was proposed on Al Ga N/Ga N heterostructure field effect transistors(HFETs) with the assistance of inductively coupled plasma(ICP) surface treatment. The effect of ICP treatment process on the 2DEG channel as well as the formation mechanism of the low annealing temperature ohmic contact was investigated. An appropriate residual Al Ga N thickness and a plasma-induced damage are considered to contribute to the low-temperature annealed ohmic contact. By using a single Al layer to replace the conventional Ti/Al stacks, ohmic contact with a contact resistance of 0.35 ?·mm was obtained when annealed at 575?C for 3 min. Good ohmic contact was also obtained by annealing at 500?C for 20 min.     

基于新型ICP脉动压力传感器的信号调理电路设计与实现

在飞行器地面试验中,新型ICP脉动压力传感器常用来测量飞行器与发射筒之间的关键位置表面由于空气脉动产生的脉动压力参数;ICP脉动压力传感器工作时需要恒流源供电,同时其输出信号不能满足大多数模数转换芯片对于输入电压的要求,针对以上问题,提出了一种基于新型ICP脉动压力传感器的信号调理电路,并详细介绍了电源电路、脉动压力信号调理电路等模块的设计原理和方法;测试结果表明该设计能够满足新型ICP脉动压力传感器3.4 mA恒流源供电需求,并且能准确地将其输出电压信号调理为0.366~2.13 V,符合AD7667转换范围要求,同时能有效地滤除信号中混入的9.6 kHz以上的高频噪声以及椭圆型高阶低通滤波器自身引入的开关噪声;该信号调理电路可靠性高,已经成功应用于飞行器地面发射试验中。     

Determination of Pb,Zr, Ti,Sr, Cr,Nb and La in lead zirconate titanate ceramics by particle‐induced X‐ray emission

A particle‐induced X‐ray emission (PIXE) technique has been used in the determination of the principal components Pb, Zr and Ti and the substituting elements Sr, Cr, Nb and La in lead zirconate titanate ceramics. In general, precision of analysis was concentration dependent from each element under study. For Pb, precision varied between 0.13% and 0.16%, at higher concentration of 59.32–64.5%. It was around 6–9% for Sr, Cr and Nb at concentrations of 1% or lower. Particular attention was devoted to the estimation of the analysis trueness. With this purpose, three methods were applied: (1) comparison of PIXE and inductively coupled plasma optical emission spectrometry concentrations, (2) recovery study and (3) comparison with a laboratory standard. Trueness of analysis was around 100 ± 10% for the evaluated elements Pb, Zr, Ti, Sr and Cr. The expected stoichiometry and elemental composition homogeneity of a wide group of produced ceramics were confirmed by the PIXE technique. Copyright © 2012 John Wiley & Sons, Ltd.     

微波消解ICP-MS法测定广西北部湾海鸭蛋中硒和锗的含量

以硝酸-过氧化氢（体积比为5：3）混合溶液为消解剂,微波消解法处理海鸭蛋样品,采用电感耦合等离子体质谱法测定样品溶液中的硒和锗的含量。选择适合的同位素元素,运用碰撞室技术（CCT）降低多原子离子对元素硒、锗的干扰,用钇作为在线内标。硒、锗工作曲线的线性范围均为0．0-100．0ng／mL,相关系数r=0．9996;硒、锗的检出限分别为1．1,0．15ng／mL,测定结果的相对标准偏差分别为4．78％,5．70％（n=6）,加标回收率为92．2％-104．0％。用该法测定国家标准物质黄鱼（GBW08573）中硒的含量,测定值在标称值范围内。     

感应耦合等离子体刻蚀在聚合物光波导制作中的应用

提出了利用感应耦合等离子体(ICP)刻蚀技术提高聚合物光波导器件性能的方法,介绍了ICP刻蚀技术的原理和优点。选取聚甲基丙烯酸甲酯-甲基丙烯酸环氧丙酯(P(MMA-GMA))作为波导材料,采用氧气作为刻蚀气体,研究了ICP参数变化对刻蚀效果的影响。介绍了倒脊形光波导的制备过程,采用改变单一工艺参数的方法,分析了刻蚀效果随时间、功率、压强、气体流量等参数的变化,对参数优化后刻蚀得到的凹槽和平板结构进行了表征。实验结果表明:在天线射频功率为300 W,偏置射频功率为30 W,气体压强为0.5 Pa,氧气流速为50 cm³/min的条件下,可获得侧壁陡直、底面平整的P(MMA-GMA)凹槽结构。