激光剥蚀电感耦合等离子体质谱新进展

简单介绍了激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)的基本原理及装置。分别对LA-ICP-MS在飞秒激光器、紫外激光器、固液气溶胶混合进样、集合式小样品标样、原位统计分布技术上的技术新进展进行了详细的评述。最后对LA-ICP-MS在元素含量分析与空间分布分析中所占的地位及其应用前景进行了展望。     

Laser Ablation Inductively Coupled Plasma Mass Spectrometry for Determination of Trace Elements in Geological Glasses

 Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used as a powerful multielement analytical method for trace analysis of geological glasses which are useful as reference materials for geochemical in-situ microanalytical work. The quantification of the analytical results was carried out using the BCR-2G and NIST 612 glass standard reference material (SRM). The experimentally determined relative sensitivity coefficients (RSC) for both SRMs vary between 0.2 and 3 for most of the elements, with increasing mass an increasing of relative sensitivity coefficients was observed. The relative standard deviation (RSD) for determination of trace element concentration of most elements (N=3) are between 2 and 10%. The determination of trace elements in various geological glasses by LA-ICP-MS yielded a good agreement with the reference values and those results of other trace analytical methods. Received October 15, 1999. Revision April 14, 2000.     

Optimization and validation of a Laser Ablation Inductively Coupled Plasma Mass Spectrometry method for the routine analysis of soils and sediments

A simple, rapid and sensitive method was developed for the routine analysis of trace elements on sediments and soils by UV-ns-LA-ICP-MS. The homogenization procedure that reduces the particle size of the samples to less than 1 µm diameter was found to be a key factor to allow for a representative sampling of the bulk soil at the micro-scale and to improve reproducibility and cohesion of the sample without requiring the use of any binder. The elimination of binders simplified the sample preparation and avoided any undesirable dilution of the sample. SEM/EDX analyses were conducted to evaluate the efficiency of laser to sample interaction. Matrix effects and different quantitation strategies were employed to demonstrate the utility of the analytical technique. Sixteen elements were analyzed on soil and sediment samples and certified reference materials. Analytical results obtained by LA-ICP-MS were comparable to solution ICP-MS analysis in terms of accuracy, precision and limits of detection. Two independent proficiency tests for trace metals in soils were conducted to compare the performance of the method versus conventional digestion ICP and AA methods, obtaining z scores ≤ 3 for all elements measured by LA-ICP-MS. An overall bias between 8 and 15% was found, depending on the sample while the overall precision was found to be better than 5% RSD for all samples. Limits of detection were as low as 0.01 mg kg^− 1.     

Calibration for Elemental Dental Tissue Analysis by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

Teeth retain different elements at particular stages of life. Hence, the exposure over a selected time span may be characterized by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). A Nd:YAG laser with emission at 266?nm was coupled to a quadrupole ICP-MS for the quantitative study of historical human teeth for Sr and Ba, elements of anthropological significance. A calibration approach incorporating the experimentally derived k coefficient is reported. The coefficients were established based on the mean concentrations of the analytes determined by pneumatic nebulization ICP-MS using acid-digested calcium phosphate standards and the intensities recorded during laser ablation of corresponding standards as pellets. The k values were 0.54?±?0.05 (µg?g^?1)^?1 and 4.49?±?1.09 (µg?g^?1)^?1 for Sr and Ba, respectively. This calibration approach provided local quantitative data and demonstrated statistically significant differences in Sr concentrations in enamel and dentine.     

激光烧蚀－电感耦合等离子体质谱法

激光烧蚀电感耦合等离子体质谱法已广泛应用于固体物质中无机元素的分析，描述了微ＬＡ—ＩＣＰＭＳ系统原理，讨论了操作参数的影响和定性及定量分析性能，并举例说明其应用。     

激光烧蚀－电感耦合等离子体质谱法

激光烧蚀电感耦合等离子体质谱法已广泛应用于固体物质中无机元素的分析,描述了微LA-ICPMS系统原理,讨论了操作参数的影响和定性及定量分析性能,并举例说明其应用。     

激光剥蚀串联电感耦合等离子体质谱在环境分析中的应用进展

激光剥蚀串联电感耦合等离子体质谱法(LA-ICP-MS)是一种功能强大的化学元素检测方法,它具有样品前处理简单、多元素同时测定、高通量、高灵敏度、宽线性范围以及原位分析等优点.同时,激光剥蚀可以与多接收器电感耦合等离子体质谱仪(MC-ICP-MS)串联用于稳定同位素组成测定,不仅避免了繁琐的样品前处理,同时还可应用于固...     

飞秒激光剥蚀-多接收等离子体质谱原位分析玄武岩玻璃样品Mg同位素组成

建立了飞秒激光剥蚀多接收等离子体质谱(fsLA-MC-ICP-MS)原位微区分析玄武岩玻璃中Mg同位素的方法.溶液进样-干气溶胶条件下浓度匹配实验表明,样品和标准样品中Mg浓度比在0.4 ～3.0时,可获得准确样品Mg同位素组成.激光剥蚀条件对Mg同位素的准确测定有明显的影响,激光剥蚀斑束和扫描速率变化,使得质谱仪的质量歧视效应随进样负载量不同而产生较大的变化,并影响样品Mg同位素组成;激光剥蚀频率与δ25 Mg正相关,与δ26 Mg负相关,当剥蚀频率大于4 Hz时,δ25 Mg和δ26 Mg趋于平稳;超快激光的能量密度对Mg同位素组成影响较小.利用本方法对国际标准样品的分析结果与参考值在误差范围内一致.本方法具有制样简单、快速的特点,且测试结果准确可靠,为火山玻璃中Mg同位素分析提供了有效的分析手段.     

激光剥蚀-电感耦合等离子体质谱对高温合金中17种痕量元素的测定

建立了镍基高温合金中Sc、Cu、Zn、Ga、Ge、As、Ag、Cd、In、Sn、Sb、Te、Ce、Hf、Tl、Pb、Bi17种痕量元素的激光剥蚀-电感耦合等离子体质谱测定方法。对激光剥蚀进样及质谱分析条件进行了优化,通过激光对样品表面的层层剥蚀顺利完成了对低沸点杂质元素的测定。采用格栅扫描采样,严格控制样品的聚焦位置和散焦距离以保证采样的准确性,由高温合金系列标准物质建立了18种痕量元素的校正曲线,其中14种痕量元素的线性相关性较好(r2≥0.99),In、Sn、Sb、Ce、Tl、Pb、Bi等超痕量元素的检出限和气体空白分别低于或接近0.000 005%和0.000 001%。方法对镍基高温合金样品中Cu、Ga、Ag、Cd、In、Sn、Sb、Te、Hf、Tl、Pb和Bi等痕量元素的测定结果与参考值吻合较好,且大部分元素的RSD(n=4)小于或接近30%。     

基于低分散激光剥蚀系统-电感耦合等离子体飞行时间质谱的快速元素成像

微量元素在生物体内含量很低,但发挥着重要的作用。因此,生物体内微量元素原位成像具有重要的意义。本文建立了基于低分散激光剥蚀系统-电感耦合等离子体飞行时间质谱（LA-ICP-TOFMS）的快速生物元素成像方法,采用点扫描模式,得到了尾静脉注射银纳米颗粒的小鼠肾脏切片中19种元素成像图,成像分辨率为20 μm,成像速度为每秒40个像素点,与常规LA-ICP-MS成像速度相比提高了约10倍。成像结果表明,不同元素在小鼠肾脏各分区中具有不同的分布模式。建立的LA-ICP-TOFMS成像方法为原位研究生物体内元素提供了直观可靠的手段,有望在生物医学研究中得到更广泛的应用。     

土壤、沉积物系列标准物质中38种元素的ICP-MS定值

探讨了电感耦合等离子体质谱测定土壤元素的基体效应及元素间的基体干扰，采用模拟土壤元素天然组成比值的校正溶液，利用^115In-^103Rh双内标校正系统有效地抑制了分析信号的动态漂移，建立了测定土壤中元素的ICP－MS方法；对GBW07410－07416土壤、沉积物系列标准物质进行定值，测定结果与XRF分析结果比较，同时用于GBW07404、GBW07405、GBW07408、GBW07309管理样分析，结果令人满意。     

激光烧蚀-多接收电感耦合等离子体质谱法测定铀颗粒物中铅杂质的同位素比值

为有效获取铀颗粒物中具有取证价值的铅杂质同位素信息,建立了激光烧蚀-多接收电感耦合等离子体质谱(LA-MC-ICP-MS)测定铀颗粒物中铅杂质同位素比值的方法.探究了诸多同位素分馏效应校正方法下铅本底对同位素测量的影响,选用的LA-MC-ICP-MS系统的本底对比值测量结果的影响小于0.001(208Pb的信号强度大于2.2× 103 cps),确定采用NIST SRM612为外标校正质量分馏,固定激光束斑直径30μm、脉冲重复率20 Hz、调节能量密度使LA-MC-ICP-MS分析NIST SRM612和铀颗粒物样品所得208Pb分别小于1.5×105 cps和3×104 cps,标准物质CRM124-4样品中206Pb/208Pb、206Pb/207Pb和207Pb/208Pb比值测量结果的相对实验标准不确定度小于0.48％、0.68％和0.40％.实际样品分析结果表明,本方法可有效区分铀颗粒物中的铅同位素比值差异,有助于鉴别其来源.     

激光剥蚀多接收杯电感耦合等离子体质谱仪原位分析硫化物铅同位素组成

采用193 nm准分子激光与MC-ICP-MS质谱仪探讨了原位微区分析过程中物质基体效应对铅同位素测定的影响,指出选择基体匹配标准物质对测定硫化物铅同位素具有重要意义.通过模拟计算发现准确测定Tl与Hg的分馏因子关系,可以在204Hg/204 Pb＜2的范围内有效校对204Hg对204 Pb的干扰.研究表明,束斑直径(24～160μm)和剥蚀频率(2～20 Hz)并不影响铅同位素组成测试.改变激光剥蚀参数可以解决MC-ICP-MS信号检测范围较窄的问题.针对目前硫化物固体标准物质缺乏的现状,采用压片法和快速熔融法制备硫化物标准物质.压片样品铅同位素组成表现出较好的均一性,而不同批次快速熔融法样品存在铅同位素分馏,仅单次制造的熔融样品内部铅同位素组成具有均匀性.结果表明,虽然快速熔融法还存在一定缺陷,但这两种方法都有望成为硫化物标准样品制作方法的备选方案.利用本方法对天然硫化物样品(黄铁矿和闪锌矿)及人工合成硫化物样品的铅同位素组成进行了准确测定,测定值与溶液值在误差范围内一致.     

微波消解-电感耦合等离子体质谱(ICP-MS)法测定板栗中的矿物元素及稀土元素

为了准确测定板栗中矿物元素和稀土元素的含量水平,采用冷冻干燥方式预处理样品,选用硝酸和过氧化氢体系微波消解样品,结合电感耦合等离子体质谱技术,建立了板栗中钠(Na)、钾(K)、镁(Mg)、锰(Mn)、铁(Fe)、钒(V)、钴(Co)等19种矿物元素及镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)、钇(Y)等15种稀土元素的同时分析测定方法。方法检出限为0.0027~0.78μg/L,相对标准偏差为1.4%~6.3%。通过国家标准物质GBW10019苹果的准确度实验验证,测定结果均在标准证书值范围内。实验结果表明,方法适用于板栗中矿物元素及稀土元素的同时测定。     

激光剥蚀-多接收电感耦合等离子体质谱法 测定含钚颗粒物中240 Pu/239 Pu比值

为高精度、准确地获取含钚颗粒物中具有核保障监督意义和核取证价值的钚同位素比值,建立了激光剥蚀-多接收电感耦合等离子体质谱(LA-MC-ICP-MS)测定含钚颗粒物中240 Pu/239 Pu的分析方法.采用检漏、安装排风罩和擦拭剥蚀池内壁等方式有效降低激光剥蚀产物沾污实验室和危及人身安全的潜在风险.联用扫描电迁移率粒径谱仪(SMPS)与激光剥蚀-多接收器等离子体质谱(LA-MC-ICP-MS)研究了激光剥蚀玻璃基体标样产生气溶胶的分布特性,结果表明,剥蚀产物的主要粒径是40~500 nm,应尽量采用水平管道连接激光剥蚀进样系统与MC-ICP-MS,含钚颗粒物分析后剥蚀池持续吹扫时间应大于15 min.采用外标归一化法离线校正质量分馏效应和离子计数器检测效率,建立了含钚颗粒物中240 Pu/239 Pu的LA-MC-ICP-MS分析方法,固定束斑直径30μm、脉冲重复率5 Hz、剥蚀时间5 s,调节能量密度使含钚颗粒物模拟样品中239 Pu的信号强度分别达2×104 cps和2×105 cps,本方法对240 Pu/239 Pu测量的相对实验标准不确定度小于1.4%(n=6),测量结果与参考值的相对偏差小于4.7%,仪器调试时间和单个样品测量时间分别为9.0和0.5 h.含钚颗粒物模拟样品分析结果表明,本方法精度高、结果准确、分析速度快,可满足核保障监督、禁产核查和核取证中含钚颗粒物直接分析的需求.     

激光剥蚀电感耦合等离子体质谱法分析Cr∶ZnSe晶体中掺杂元素Cr的含量和分布

采用激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)法研究激光晶体材料Cr∶Zn Se晶体中掺杂元素铬(Cr)的含量和分布。利用镀膜扩散掺杂方法,制备不同掺杂浓度的Cr∶Zn Se晶体标准样品作为固体标准物质,实现Cr∶Zn Se晶体中Cr的定量分析。LA-ICP-MS法研究自制标准样品中Cr的分布均匀性,电感耦合等离子体光谱法测定其准确含量。通过激光点剥蚀和线扫描剥蚀采样,获得Cr元素的点位和含量分布信息,实现晶体中Cr的原位微区分析。标准工作曲线相关系数0.9992,检出限0.08 mg/kg。本方法可为不同生长条件下Cr∶Zn Se晶体中Cr的统计分布分析提供有效检测手段。     

Application of Inductively Coupled Plasma Mass Spectrometry to the determination of uranium isotope ratios in individual particles for nuclear safeguards

The capability of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of uranium isotope ratios in individual particles was determined. For this purpose, we developed an experimental procedure including single particle transfer with a manipulator, chemical dissolution and isotope ratio analysis, and applied to the analysis of individual uranium particles in certified reference materials (NBL CRM U050 and U350). As the result, the ²³⁵U/²³⁸U isotope ratio for the particle with the diameter between 0.5 and 3.9 μm was successfully determined with the deviation from the certified ratio within 1.8%. The relative standard deviation (R.S.D.) of the ²³⁵U/²³⁸U isotope ratio was within 4.2%. Although the analysis of ²³⁴U/²³⁸U and ²³⁶U/²³⁸U isotope ratios gave the results with inferior precision, the R.S.D. within 20% was possible for the measurement of the particle with the diameter more than 2.1 μm. The developed procedure was successfully applied to the analysis of a simulated environmental sample prepared from a mixture of indoor dust (NIST SRM 2583) and uranium particles (NBL CRM U050, U350 and U950a). From the results, the proposed procedure was found to be an alternative analytical tool for nuclear safeguards.     

Elemental Analyses Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) of Geological Samples Fused with Li2B4O7 and Calibrated Without Matrix-Matched Standards

 Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used as a complementary technique to X-ray fluorescence (XRF), for multi-element analysis of geological samples fused with lithium-tetraborate Li₂B₄O₇). Different calibration strategies using external non-matrix matched reference materials were investigated. Various internal standards were tested, including the use of Li from the flux, and the use of the naturally occurring internal standards, Si or Ca. The use of a naturally occurring standard is not as efficient as this required a prior analysis of the samples using XRF. The obtained values for the analysis of geological reference materials were compared with consensus literature values, and satisfactory agreement was found. Laser pits, which were formed, had a diameter of 80 μm and 3–5 replicates on each fused disc were measured. The reproducibility of the method was better than 10% for concentrations above 1 μg/g and better than 15% for lower concentrations. The use of Li as the internal standard offers the possibility of multi-element determinations in geological samples, which have an unknown composition when the laser ablation analysis is carried out. However, using the calculated stoichiometric composition of the lithium-tetraborate for the calculation of the Li concentration leads to a constant deviation from the recommended values. Therefore, it was necessary to determine the Li concentration within each sample batch using at least one lithium tetraborate fused geological reference material. This resulting Li concentration in the beads was then used for all subsequent samples in a run. Limits of detection, reproducibility, deviation from reference values indicate the potential of LA-ICP-MS for such bulk analysis without matrix matched calibration standards.     

激光熔蚀微探针-电感耦合等离子体质谱法--一种快速测定岩石样品中多个元素的新方法

利用激光探针与等离子体质谱联机技术(LAM-ICPMS)同时测定岩石样品中35个元素.对岩石标样的碱熔玻璃进行了系统的LAM-ICPMS方法研究.结果表明,采用散焦(defocus)激光束扫描法获得了连续稳定的分析信号,并提高了分析灵敏度和分析精密度.该法测定P的检出限为0.1%,Sc、Ti、V、Cr、Mn、Co及Ni的检出限为1.6×10-6～12×10-6,Ga、Rb、Sr及Ba的检出限为0.2×10-6～0.6×10-6,其余21个微量元素的检出限为10-9级;内部精度优于15%,外部精度优于10%.3个岩石标样(NTUG-1、NTUG-2及NTUG-3)的测量结果表明LAM-ICPMS是一种同时测定岩石样品多元素的快速有效方法.     

Combining Ammonium Pyrrolidine Dithiocarbamate/methyl Isobutyl Ketone Microextraction in an Inexpensive Disposable Pipette with Laser Ablation Inductively Coupled Plasma Mass Spectrometry for the Determination of Cd and Pd

This paper describes a new analytical method, using a combination of ammonium pyrrolidine dithiocarbamate/methyl isobutyl ketone (APDC‐MIBK) microextraction and laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS), for the determination of the concentrations of Cd and Pb in aqueous samples. Only 200 μL of organic solvent was used throughout the entire analysis process, with enhancement factors as high as 25. Recoveries from replicate analyses of natural water [NIST 1640(a)] containing mean concentrations of 3.1 μg Cd L^?1 and 9.3 μg Pb L^?1 were 95 ± 3 and 104 ± 4%, respectively. The corresponding detection limits were 0.6 μg L ^?1 for Cd and 0.9 μg L ^?1 for Pb. The main advantage of this approach is its simplicity in terms of sample preparation, as demonstrated by quantifying the levels of Cd and Pd in real samples, including tap water, groundwater, and seawater, using a standard addition method.