ICP微等离子体射流在快速成形制造中的应用

本文开展了大气压甚高频感应耦合(ICP)微等离子体射流的特性与应用研究.在150 MHz甚高频,功率为90 W条件下获得温度高达上千度的温热等离子体射流,射流长度近3 cm.随着气流量的增加射流将呈现层流到湍流的转变,长度先增后减;而功率对于射流长度的影响存在着一个上限,当等离子体吸收的能量与扩散损失的能量达到平衡时,射流长度将达到最大.利用这种ICP微等离子体射流进行了微尺寸金属铜的快速成形制造,得到了球冠状和柱状铜金属件.在扫描电子显微镜下观察到沉积物表面最小颗粒尺寸远小于铜粉颗粒;X射线衍射结果显示沉积物表面存在弱氧化物峰,这是沉积过程中空气被射流卷入所致.     

电感耦合等离子体质谱法测定铜矿区20种植物中的金银

采用灰化-王水处理试样,选取103 Rh和203 Tl作为测定107 Ag、109 Ag和197 Au的内标元素,建立了电感耦合等离子体质谱法测定铜矿区栓皮栎等20种植物中金和银的方法。所建立方法用于不同矿区植物样品的分析,相对标准偏差(n=5)为9.05%～0.85%,加标回收率在93.6%～101.6%之间,Au和Ag检出限分别为0.048和1.06ng.g-1。该方法简便、准确,适用于铜矿区植物中金和银的测定。测定结果表明,矿区中金和银含量因不同植物而存在较大差异,变动范围为Au:0.18～0.99ng.g-1,Ag:282～2 150ng.g-1,其中凤尾蕨、芒萁和长叶实蕨中Ag具备地球化学异常特征,可作为找矿有效指示的植物。     

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。     

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.     

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...     

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.     

Correction factor based on the ratio of the magnesium atom to ion background signals used for evaluating robustness in inductively coupled plasma optical emission spectrometry

The ratio of the magnesium ion to atom signals with wavelengths of 280.270 and 285.213 nm, respectively, is frequently employed to estimate plasma robustness in inductively coupled plasma optical emission spectrometry. To guarantee a rigorous and accurate calculation of this indicator of the plasma condition, a correction for the difference in the response of the instrument at the two wavelengths of magnesium has been frequently applied. However, the literature reviewed shows inconsistencies in the values of the correction factor used. Also it is notable the lack of information concerning the procedures to calculate such correction factor.

In this paper, we propose a simple method for the best estimate of the correction factor from an appropriate measurement of the magnesium atomic and ion background signals, when a blank solution, contaminated by magnesium, is nebulized. We proved that a bad selection of the wavelengths used for background signal estimation can underestimate the correction factor up to a 56%.     

The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma optical emission spectrometry

A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte elements. Ultrasound-assisted two-step digestion with digestion solutions of 6 mL of HNO₃ (Step 1) and 3 mL of HNO₃ + 3 mL of HF (Step 2) resulted in recovery rates of over 92% for all the analyte elements with one exception, chromium, which had a recovery of about 85%. The analysis of SRM 1633b showed that the two-step ultrasound-assisted digestion method developed resulted in chromium, copper, nickel and zinc concentrations higher than the microwave digestion method standardized by the United States Environmental Protection Agency (USEPA method 3052). This is the very first time when a digestion method using ultrasound resulted in higher efficiency than microwave (USEPA method 3052) for chromium and nickel in very hard to dissolve samples. The major advantages of the ultrasound-assisted digestion over microwave digestion is the high treatment rate (about 30 samples simultaneously with a sonication time of 18 min) and the possibility to use new sample vessels without a significant increase in costs.     

激光诱导击穿光谱定量检测土壤微量重金属元素方法研究

在对激光诱导击穿光谱数据分析的基础上提出了一种可以用于元素定量分析的方法。该方法利用傅里叶分析的方法研究了光谱数据中的不同部分(白噪声、热辐射噪声和原子发射光谱),通过带通滤波实现发射光谱与大部分噪声的分离,得到仅含少量白噪声的发射光谱;通过计算待量化元素谱线与其对应单位强度特征谱线的相似度引入卷积强度来衡量待测谱线的强度。选取Cu 324.75nm作为分析线,Ti 337.28nm谱线作为参考线,采用上述方法对含微量Cu元素土壤样品进行了测量。实验结果显示:Cu元素含量和其卷积强度的线性系数达到0.997 9,计算得到土壤中Cu元素的检测限为44mg.kg-1,达到国家土壤环境质量标准规定的二级土壤中Cu含量要求,测量相对误差在10%以内,表明该方法能够满足土壤微量重金属检测简便、快速的要求。     

电感耦合等离子体发射光谱法测定高铬铸铁中的铬、镍、铜、锰、磷、硅、钼和钛

摘要高铬铸铁样品经微波消解,以氧化钇为内标,用电感耦合等离子体发射光谱法同时测定样品溶液中的铬、镍、铜、锰、磷、硅、钼和钛.分析了3种有证国家标准物质,测定值同证书值吻合,验证了方法的准确性.     

响应面法优化超声辅助提取-原子荧光法快速测定茶叶痕量汞

研究了一种使用超声波辅助提取(UAE)-原子荧光法测定茶叶痕量汞的快速方法.采用Plackett-Burman设计从6个影响汞提取率的因素中筛选出3个显著因素—超声时间St,超声温度T和HNO3:H2O2(1:1,δ)体积A2,并采用中心组合设计和响应面法优化参数.结果表明,最优提取条件为,浸泡时间6 min,St 8...