荧光探针检测香烟主流烟雾活性氧的机理研究

不具有荧光的探针双氢罗丹明6G被氧化后可以生成具有荧光特性的罗丹明6G。反应中,一个双氢罗丹明分子能够与2个活性氧发生作用。借助衍生荧光检测技术,可以将该探针用于香烟主流烟雾活性氧含量的检测实验。利用探针在该实验条件下检测市场上4种品牌香烟的主流烟雾中活性氧的含量,含量分别为：(59.93±5.32)nmol,(55.98±6.17)nmol,(54.78±7.82)nmol,(40.87±6.43)nmol。实验结果表明,香烟主流烟雾中活性氧的含量与烟草品种及制作工艺存在密切的联系。借助荧光特性进行主流烟雾活性氧含量近实时检测的方法具有灵敏度高与检测速度快的特点。     

激光剥蚀电感耦合等离子体质谱鉴别蓝色圆珠笔色痕

建立了法庭科学中蓝色圆珠笔色痕的激光剥蚀电感耦合等离子体质谱鉴别方法。对95种不同来源的蓝色圆珠笔进行了分析,依据所含金属元素种类的差别将95种圆珠笔分为34类,其中26类圆珠笔根据元素种类的差别可直接区分,其余8类依据元素间响应值之比进行区分,对字痕载体纸张的考察结果表明了纸张对检测结果无影响。实验结果表明方法重现性良好,精密度10%,与传统分析技术相比,本方法可获得更好的鉴别结果,95种蓝色圆珠笔中有88种可使用该方法有效鉴别。该方法简便快速、精密度良好、对样本宏观无损,适合法庭科学对蓝色圆珠笔鉴定的需要。     

电感耦合等离子体质谱法测定饮用水中6种痕量重金属元素

采用电感耦合等离子体质谱(ICP-MS)法同时测定饮用水中的镉、铬、铅、锌、铜、镍6种元素的含量.对仪器工作参数进行了优化,选取45Sc,72Ge,115In, 209Bi作为测定元素的内标元素,有效克服了基体效应、接口效应及仪器波动所产生的影响,利用八极杆碰撞/反应池技术,消除多原子离子对待测元素的干扰.测定元素校准曲线的相关系数都在0.999 7以上,各元素的检出限在0.70～77.0 ng·L-1之间,相对标准偏差(RSD)介于0.47%～1.69%之间.测定标准参考物GBW08607,测定值均在标准值范围内.对4个地区的饮用水进行了检测,样品加标回收率为92%～108%.该方法具有简便、快速、准确、稳定的特点,可作为饮用水中痕量元素检测的可靠方法.     

电感耦合等离子体质谱法测定高钝镉中的杂质元素

采用电感耦合等离子体质谱光测定离纯镉中的杂质元素。讨论了镉基体的谱线干扰,比较了镉基体产生的多原子离子的干扰程度,该干扰按ＣｄＨ、ＣｄＯ、ＣｄＯ２、ＣｄＡｒ、ＣｄＯＨ和ＣｄＯＨ２顺序递减。研究了不同浓度镉基体对分析物信号的抑制或增强效应,镉的浓度大于０．２５ｇ·Ｌ＾－１时,对质量数小于１００的分析物的信号强度产生抑制,而以质量数大于１５０的分析的信号强度产生增强,采用＾８９Ｙ和＾２０９Ｂｉ作内标分     

密闭微波消解-电感耦合等离子体质谱法测定烟用香精中多种微量元素

烟用香精对卷烟的香、吃味和质量稳定有重要影响,为了有效控制香精质量,降低卷烟主流烟气中有害元素的含量,采用密闭微波消解-电感耦合等离子体质谱法同时测定了烟用香精中铍、钒、铬、锰、镍、铜、锌、砷、硒、锶、钼、镉、铊和铅14种元素,方法的线性相关系数0.999 5~1.000 0,相对标准偏差1.3%~9.5%(n=5),检出限0.003~0.13μg.L-1,加标回收率88.1%~109.3%。结果表明方法能够满足微量元素的分析要求。用实验方法测定了38个牌号烟用香精中铍、钒等14种元素的含量。结果发现:(1)香精中锰、锌、锶的含量较高,硒、镍、铬、铜次之,铍、铊、钼、镉、钒、铅和砷的含量最低,其平均值均小于0.1μg.g-1。(2)锰、镉、锶的含量在不同香精之间差别较大,其变异系数分别为276.4%,238.7%,243.8%。     

Standardless analysis of solids by mass spectrometry with inductively coupled plasma

The possibility of the standardless mass spectrometric analysis of the elemental composition of solids has been discussed. The effect of each stage of the laser plasma expansion on the formation of the coefficient of relative sensitivity of elements in the sample has been studied theoretically and experimentally. It has been shown that the stages of ionization and detection make the main contribution to the formation of the coefficient of relative sensitivity. It has been proposed to separate dissociation and ionization processes in time and/or in space. To compensate for the energy spread of ions at the output of the analyzer, a circuit has been proposed for aligning the energy of ions before their detection.     

Effect of the matrix in mass spectrometry using an inductively coupled plasma

Using different types of devices, we have performed an experimental study of matrix ionization effects manifesting themselves in the method of mass spectrometry with an inductively coupled plasma. Basic laws governing these effects have been established. The composition of the analytical zone of the plasma and possible attenuation of the signal from the analyte on introduction of a matrix element due to processes occurring in the plasma and in the ion beam have been determined theoretically. A high degree of coincidence between experimental and calculated results is shown. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 768–774, September–October, 1998.     

Spectral interferences from polyatomic barium ions in inductively coupled plasma mass spectrometry

For the Element2 (a relatively new high-sensitivity magnetic sector ICP MS), we have studied spectral interferences from barium arising as a result of polyatomic barium ions, which have a considerable effect on the intensity of lines for rare-earth isotopes. We have shown that the parameters characterizing the interferences (the ratios of the signals from oxygen-containing, chlorine-containing, and fluorine-containing BaX⁺ ions to the Ba⁺ signal, and the apparent rare-earth concentrations C_{app j} resulting when overlap from polyatomic Ba occurs) are higher for the Element2 than for a quadrupole instrument (PQ2⁺). However, it is possible to solve many spectral overlap problems when using the Element2 by using the medium-resolution (MR) or high-resolution (HR) modes. We have estimated the resolutions needed to completely separate the masses of the polyatomic barium ions and the rare-earth isotopes in the spectrum. For cases when it is impossible to use the high-resolution mode due to the ∼100-fold decrease in sensitivity, we recommend preliminary separation of Ba from the rare earths. In this work, we have used extraction chromatography to determine low rare-earth concentration levels in Lake Baikal water. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 813–818, November–December, 2006.     

应用电感耦合等离子体质谱研究黄铁矿焙烧灰渣的标识元素

应用ICP-MS研究了黄铁矿干法焙烧灰渣中16种元素与堆存地周围近、远处土层中元素的相关性,以及它们的相似和显著差异元素比.发现在污染的土层中,Tl,Cd,Cs,Cu,Zn,Mn,Pb和Ni都是较易辨识的、与渣灰有相关性或相似比的元素.仅有Tl,Cd,Zn,Ni适合作为元素相似性的判据对象.在渣灰和土壤中,不同组合的T...     

激光剥蚀-电感耦合等离子体质谱测定植物样品中的元素

采用193 nm准分子激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)对标准植物粉末样品(GBW07602-GBW07603灌木枝叶、GBW07604杨树叶、GBW07605茶叶、GBW08514烟草)中13种元素(Li,B,Na,Mg,Al,K,Ca,Cr,Mn,Fe,Ni,Cu,Ba)进行定量测试.向植物粉末样...     

Detection and quantification of multiple molecular species in mainstream cigarette smoke by continuous-wave terahertz spectroscopy

Continuous-wave terahertz spectroscopy by photomixing is applied to the analysis of mainstream cigarette smoke. Using the wide tunability of the source, spectral signatures of hydrogen cyanide (HCN), carbon monoxide (CO), formaldehyde (H2CO), and water (H2O) have been observed from 500 to 2400 GHz. The fine spectral purity allows direct concentration measurement from the pure rotational transitions of HCN and CO. The quantification of the measurement was validated by the means of a calibration gas containing CO. The potential of this technique for trace gas detection is demonstrated with an estimated detection limit of HCN equal to 9 parts in 10(6).     

Determination of trace BrO3- and Br- in Chinese patent drugs, waters and beverages by ion chromatography coupled with inductively coupled plasma mass spectrometry

In the present study, a method for determination of BrO3- and Br- using ion chromatograghy coupling with inductively coupled plasma mass spectrometry (IC-ICP-MS) was developed. BrO3- and Br- were separated on a Hamilton PRP X-100 (150 x 4.1 mm, 10 microm) column guarding with a On-guard II RP (4 x 50 mm) column with 10 mmol x L(-1) NH4NO3 eluent solution at 2 mL x min(-1). By using 200 microL sample loop, the detection limits for BrO3- and Br were 0.35 and 0.36 microg x L(-1), respectively. BrO3- had good linearity in the range 4.8-160.0 ng x L(-1). The standard solution linear equation was y = 250.31x-45.43, and R2 = 0.9999. Br had good linearity in the range 4.2-140.0 ng x L(-1). The standard solution linear equation was y = 186.84x-127.10, and R2 = 0.9994. Recoveries of spiked samples were 98.9%-109.5% and 97.4%-106.1%, respectively. The samples included various kinds of Chinese patent drugs, waters, and beverages. Among them, 14 bottled drinking waters and 2 kinds of tap waters were found containing BrO-, while other samples were under BrO3- detection limit. Br- was detected in all samples.     

基于COMSOL 的感应耦合等离子体炬多物理场研究

为了优化锂微粉等离子体球化的工艺,对感应耦合等离子体炬进行二维建模,将电磁场计算域扩展到等离子体放电区域之外的空气区域,利用COMSOL 软件进行多物理场模拟。得到了等离子体的电磁场、温度和速度分布,并对分布形成的物理机制进行分析。模拟发现等离子体区域线圈段存在上下两组对称的回流涡,线圈段中部靠近约束管处等离子体速度分布杂乱,有激烈的径向打壁现象,乱流预计会对约束管壁相应位置造成一条环状的破裂效果。基于模拟结果,提出在采用感应耦合等离子体球化锂微粉的工艺工程中,可以将注粉口下移,绕开上回流涡。     

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In order to optimize the process of plasma spheroidization of the lithium micro-powder, a 2-D model of inductively coupled thermal plasma torch is presented. The calculating domain of the electromagnetic field is extended to the air region outside the plasma discharge region and multi-physics coupling calculation was performed by using COMSOL software. The plasma electromagnetic field, temperature and velocity distributions are obtained. The physical mechanism of distributions is analyzed. The simulation found that there are two sets of symmetrical reflux vortices in the coil section of the plasma region. The velocity distribution which locates in the center of coil section and closes to the wall of confinement tube is in disorder. The plasma particles hit the wall along the radial direction. Disorderly flow may cause a rupture area along the circular tube wall. Based on the simulation results, it is proposed that in the process of inductively coupled plasma spheroidization, powder injection port can be moved down to avoid the upper reflux vortex.     

Microfluidic chip-inductively coupled plasma mass spectrometry for trace elements and their species analysis in cells

Abstract

Accurate identification and quantification of trace elements and their species in cells is an important prerequisite for the exploration of their physiological function and related mechanisms of process involving trace elements/species in human body. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful analytical instrument for trace elements detection, while it still suffers from insufficient limits of detection, interference from complex cell matrix, and incompatible sample consumption in cells analysis. Microfluidic chips which possess advantages of low sample/reagent consumption, rapid analysis speed and high spatial resolution provide perfect miniaturized and integrated platforms for cell analysis. In this article, microfluidic chip-ICP-MS techniques for trace elements and their species analysis in cells were reviewed. Both chip-based pretreatment techniques (e.g., magnetic solid phase microextraction (MSPME), monolithic capillary microextraction (MCME), liquid phase microextraction (LPME)) including chip-based array microextraction techniques for trace elements and their species analysis and droplet chip for single cell analysis were introduced. The newly developed methods of microfluidic chips in combination with ICP-MS for trace elements and their species analysis in small numbers of cells and even single cell were critically discussed, including chip-based MSPME/MCME/LPME-(electrothermal vaporization-ICP-)MS, on-line chip-based array MSPME/MCME-ICP-MS, on-line chip-based array MSPME-high performance liquid chromatography-ICP-MS and online droplet chip-time-resolved ICP-MS. These methodologies were demonstrated with high sensitivity, high throughput, good matrix resistance and low sample/reagent consumption, contributing to the quantification of trace elements/species in cells and even single cells. Relevant 20 references are included herein, and the development trend of microfluidic chip-ICP-MS techniques for cells analysis is prospected.     

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将等离子体作为磁流体,考虑其流体属性和电磁属性,介绍了利用FLUENT软件包并将其进行二次开发,解算电磁场方程、质量连续性方程、动量守恒方程、以及能量守恒方程的数值模拟方法,得到了以磁矢势为表达形式的电磁场分布、温度分布和速度分布.数值模拟了粉末球化所用的感应耦合等离子体炬电磁场分布、温度分布、速度分布.分析了温度分布、速度分布产生的物理原因,为感应耦合等离子体炬球化粉末颗粒提供理论性指导.     

凝胶电泳与激光剥蚀-电感耦合等离子体质谱联用测定蛋白质中微量元素的应用进展

介绍了凝胶电泳(GE)和激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)联用测定蛋白质中微量元素的方法,对蛋白质分离、凝胶处理,包括染色及干燥,和检测过程中的定量校正等技术问题做了详述,并综述了LA-ICP-MS在硒蛋白、磷酸化蛋白及金属蛋白分析中的应用,指出了这种方法在蛋白质中微量元素检测中存在的问题和发展方向。     

Investigation of heavy-metal accumulation in selected plant samples using laser induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

Single-pulse Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass-Spectrometry (LA-ICP-MS) were applied for mapping the silver and copper distribution in Helianthus Annuus L. samples treated with contaminant in controlled conditions. For Ag and Cu detection the 328.07 nm Ag(I) and 324.75 nm Cu(I) lines were used, respectively. The LIBS experimental conditions (mainly the laser energy and the observation window) were optimized in order to avoid self-absorption effect in the measured spectra. In the LA-ICP-MS analysis the Ag 107 and Cu 63 isotopes were detected. The capability of these two analytical techniques for high-resolution mapping of selected trace chemical elements was demonstrated.     

Fabrication of single-mode ridge SU-8 waveguides based on inductively coupled plasma etching

In this paper, a systematic study has been performed for the etching of negative photoresist SU-8 2005 using inductively coupled plasma. The etching rate, vertical profile, surface and sidewall roughness of the waveguide were investigated as a function of the chamber pressure, the bias power, the antenna power, the ratio of flow rate of Ar to O₂, and the etching time. The etching parameters were studied in detail and optimized to minimize the surface roughness in etched areas. Ridge MZI waveguides with SU-8 2005 were fabricated under the optimized etching conditions, resulting in smooth and almost vertical patterns. The waveguides showed single-mode propagation at 1550 nm wavelength and low propagation loss of less than 1.565 dB/cm, which was similar to the waveguides fabricated by the wet-etching technique.     

射频电感耦合夹层等离子体中的模式转换

本文利用微波相位法和光谱诊断法, 研究了ICP放电等离子体在圆台状夹层等离子体中E模和H模相互转换的物理现象. E模和H模的之间转换过程是一个瞬间突变的, 转换点的输入功率随真空室压强的变化而变化. H模向E模转换的阈值功率低于E模向H模转换的值, 等离子体参数随输入功率变化曲线类似于铁磁物质中的磁滞回线. Ar II 408.2 nm谱线的强度的变化规律和电子密度随功率变化的规律基本一致. 通过本实验可以获得一种电子密度范围为3.85×10¹¹ cm^-3 < n_e < 4.68× 10¹¹ cm^-3, 外表面积为0.3 m², 厚度为2 cm稳定工作的等离子体源.