Determination of trace elements in zeolites by laser ablation ICP-MS

Laser ablation inductively coupled plasma mass spectrometry using a quadrupole-based mass spectrometer (LA-ICP-QMS) was applied for the analysis of powdered zeolites (microporous aluminosilicates) used for clean-up procedures. For the quantitative determination of trace element concentrations three geological reference materials, granite NIM-G, lujavrite NIM-L and syenite NIM-S, from the National Institute for Metallurgy (South Africa) with a matrix composition corresponding to the zeolites were employed. Both the zeolites and reference materials were fused with a lithium borate mixture to increase the homogeneity and to eliminate mineralogical effects. In order to compare two different approaches for the quantification of analytical results in LA-ICP-MS relative sensitivity coefficients (RSCs) of chemical elements and calibration curves were measured using the geostandards. The experimentally obtained RSCs are in the range of 0.2-6 for all elements of interest. Calibration curves for trace elements were measured without and with Li or Ti as internal standard element. With a few exceptions the regression coefficients of the calibration curves are better than 0.993 with internal standardization. NIM-G granite reference material was employed to evaluate the accuracy of the technique. Therefore, the measured concentrations were corrected with RSCs which were determined using lujavrite reference material NIM-L. This quantification method provided analytical results with deviations of 1-11% from the recommended and proposed values in granite reference material NIM-G, except for Co, Cs, La and Tb. The relative standard deviation (RSD) of the determination of the trace element concentration (n = 5) is about 1% to 6% using Ti as internal standard element. Detection limits of LA-ICP-QMS in the lower microg/g range (from 0.03 microg/g for Lu, Ta and Th to 7.3 microg/g for Cu, with the exception of La) have been achieved for all elements of interest. Under the laser ablation conditions employed (lambda: 266 nm, repetition frequency: 10 Hz, pulse energy: 10 mJ, laser power density: 6 x 10(9) W/cm2) fractionation effects of the determined elements relative to the internal standard element Ti were not observed.     

Determination of trace elements in steel by laser ablation inductively coupled plasma mass spectrometry.

A rapid quantitative analysis of the trace elements in steel by laser ablation inductively coupled plasma mass spectrometry is described. The conditions for laser ablation and normalization methods to improve the analytical precision are given. The optimum conditions for laser ablation were achieved when the ion yield was a maximum at the focus position in the fixed Q pulse mode, and above the focus position in the Q-switched pulse mode. It was found that the fixed Q pulse mode was most suitable for the determination of trace metal elements in steel, and that the Q-switched pulse mode was most suitable for both non-metallic elements and elements with a high boiling-point. In order to improve the analytical precision for those elements with a strong background intensity, normalization methods with both the matrix ion, 57Fe+, and 38Ar+ are proposed.     

Determination of trace elements in geological samples by laser ablation inductively coupled plasma mass spectrometry

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied for the sensitive multi-element analysis of traces and ultra-traces in geological samples. In order to prepare homogeneous targets the powdered geological samples were melted together with a lithium-borate mixture (90% Li₂B₄O₇, 10% LiBO₂) in a muffle furnace at 1050 °C. The quantification of the analysis results was carried out using the BCR-2G and BM 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, whereas the relative standard deviation (RSD) of the determination (N = 3) of the concentration was 5–20%. The analysis results of LA-ICP-MS for various geological samples are in agreement with those of other methods. Received 31 March 1999 / Revised: 26 May 1999 / Accepted: 31 May 1999     

Determination of trace elements in geological samples by laser ablation inductively coupled plasma mass spectrometry

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied for the sensitive multi-element analysis of traces and ultra-traces in geological samples. In order to prepare homogeneous targets the powdered geological samples were melted together with a lithium-borate mixture (90% Li₂B₄O₇, 10% LiBO₂) in a muffle furnace at 1050?°C. The quantification of the analysis results was carried out using the BCR-2G and BM 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, whereas the relative standard deviation (RSD) of the determination (N = 3) of the concentration was 5–20%. The analysis results of LA-ICP-MS for various geological samples are in agreement with those of other methods.     

ICP-MS法测定高纯钛中痕量元素

建立了ICP-MS直接测定高纯钛中Be,V,Co,Ni,Ga,Mo,Nb,Cd,Sb,TI,Pb的分析方法,并对ICP-MS工作参数及条件进行了优化和选择.高纯钛用HF与HNO3溶解后加入Sc、Cs、Re内标,用ICP-MS直接检测.方法的检出限为0.03～0.1 ng/mL,测定下限为0.2～0.5 ng/mL,各元...     

珍珠中痕量稀土元素的ICP-MS测定及其分布特性

探讨了等离子体质谱(ICP-MS)分析珍珠样品中稀土元素的基体效应及多原子离子干扰,并采用干扰校正因子进行有效的校正,以In-Rh双内标校正体系进行分析信号动态漂移的监控和补偿,建立了珍珠样品中稀土元素的ICP-MS分析方法。方法的定量检出限为0．1～0．5ng／g,RSD≤15％(n=5)。所建立的方法用于标准物质Gui-1、Gui-2、Gui-3及人工养殖珍珠的分析。珍珠中稀土元素的分布与分馏特性与其生长环境密切相关。     

Improvements in calibration procedures for the quantitative determination of trace elements in carbonate material (mussel shells) by laser ablation ICP-MS

A better repeatability and accuracy in the quantitative determination of trace elements in mussel shells or carbonate-based materials by LA-ICP-MS was achieved by using a series of multielement calibration standards prepared by co-precipitation of twelve elements into a CaCO₃ matrix in order to improve the homogeneity of the resulting powder samples. Pressed powder discs of good mechanical stability could be obtained at a pressure of 50 MPa, without the addition of a binder. An UV laser (modified Nd:YAG, 266 nm) was used in the Q-switched mode at a repetition rate of 10 Hz and an energy level of 3.5 mJ. Correlation coefficients (R) for the linear calibration graphs (concentration range: 1.5–400 μg/g) for Cr, Mn, Co, Cu, Zn, As, Cd, Sn, Ba, and Pb are generally better than 0.997. The detection limits for all elements investigated are in the sub-μg/g range. Incorporation of elements into the matrix by co-precipitation has shown as a superior method for producing calibration standards than the simple mixture of the analytes (in carbonate or oxide form) with the matrix (CaCO₃) or addition of standard solutions to a carbonate powder base. Two examples of the quantitative determination of toxic elements in mussel shells will be presented. Received: 10 January 2000 / Revised: 16 March 2000 / Accepted: 26 March 2000     

Improvements in calibration procedures for the quantitative determination of trace elements in carbonate material (mussel shells) by laser ablation ICP-MS

A better repeatability and accuracy in the quantitative determination of trace elements in mussel shells or carbonate-based materials by LA-ICP-MS was achieved by using a series of multielement calibration standards prepared by co-precipitation of twelve elements into a CaCO3 matrix in order to improve the homogeneity of the resulting powder samples. Pressed powder discs of good mechanical stability could be obtained at a pressure of 50 MPa, without the addition of a binder. An UV laser (modified Nd:YAG, 266 nm) was used in the Q-switched mode at a repetition rate of 10 Hz and an energy level of 3.5 mJ. Correlation coefficients (R) for the linear calibration graphs (concentration range: 1.5-400 microg/g) for Cr, Mn, Co, Cu, Zn, As, Cd, Sn, Ba, and Pb are generally better than 0.997. The detection limits for all elements investigated are in the sub-microg/g range. Incorporation of elements into the matrix by co-precipitation has shown as a superior method for producing calibration standards than the simple mixture of the analytes (in carbonate or oxide form) with the matrix (CaCO3) or addition of standard solutions to a carbonate powder base. Two examples of the quantitative determination of toxic elements in mussel shells will be presented.     

GD-MS法和ICP-MS法测定高纯铌中痕量元素

采用辉光放电质谱法(GD-MS)对高纯铌中Ta,Mo,W等痕量杂质元素进行了测试,并对GD-MS工作参数进行了优化,部分元素与采用电感耦合等离子体质谱法(ICP-MS)定量分析的结果进行比较,对某些元素含量差别较大的原因进行了分析,论述了Element GD辉光放电质谱仪的特点及其在痕量杂质分析上的优势。     

基体匹配—电感耦合等离子体质谱(ICP-MS)法测定萤石精矿中痕量有害元素

为向萤石精矿质量检测和环境监管提供可靠的数据支撑，采用基体匹配—电感耦合等离子质谱法测试萤石精矿中痕量有害元素铜、锌、砷、镉和铅的含量。利用硝酸溶解分析纯碳酸钙后，经ICP-MS测试溶液中钙元素含量与理论值偏差约6%。钙溶液经不同倍率稀释后配置基体浓度为1000、2000和5000mg/L多元素标准溶液，在ICP-MS测试不同基体浓度混合标准溶液的内标回收率稳定性和IF/BK压降情况后，确定了1000 mg/L的最佳基体浓度。在传统四酸消解法基础上，通过改变加酸顺序、用量和温控水平，实现对萤石精矿的完全消解。消解实验中，同步设置消解加标、过程空白和空白加标实验。萤石精矿在消解定容及适度稀释后，溶液中离子浓度与复杂基体标准溶液的最佳基体浓度接近。在复杂基体标准溶液及样品消解液测试中，采用He模式的碰撞反应池技术，选用72Ge、115In和175Lu作为内标元素。结果显示：各元素标准曲线线性大于0.9995，各样品内标回收率在80%-110%范围波动，表明基体匹配联合内标校正，有效消除了复杂样品测试中的非质谱和质谱干扰。消解实验中未产生过量的元素沉淀或挥发损失，加标样品各有害元素回收率在90%-120%。质控样品各元素含量测试误差在15%以内。此测试方法中铜、锌、砷、镉和铅的检出限分别为4.81、8.65、17.91、0.49和2.84 μg/L，可满足复杂基体样品中痕量元素含量的准确测试需求。     

Investigations of trace elements in high salinity waters by ICP-MS

A separation and enrichment procedure for the analysis of trace elements (Cd, Co, Cu, Fe, Mn, Ni, Pb, Tl, U, Zn) in seawater or brines from ore dumps by ICP-MS was established based on the complexation with sodium diethyldithiocarbamate-trihydrate (Na-DDTC) and separation on a phenyl column. The method was tested with seawater samples from the hydrothermal system of Axial Seamount, Juan de Fuca Ridge. The analytical results demonstrated the influence of hydrothermal activity on the concentration of Fe and Mn. Received: 2 December 1998 / Revised: 25 February 1999 / Accepted: 1 March 1999     

电感耦合等离子体质谱法同时测定成品烟烟丝中7种微量元素

采用微波消解前处理样品,电感耦合等离子体质谱检测,同时测定了成品烟烟丝中Cr、Ni、Cu、As、Se、Cd、Pb等7种微量元素。方法的回收率92.8%~120%,检出限25.2~245 ng/L,相对标准偏差均小于10%。分析和比较了5种国外卷烟和10种国内卷烟烟丝中7种元素的含量。     

Investigations of trace elements in high salinity waters by ICP-MS

A separation and enrichment procedure for the analysis of trace elements (Cd, Co, Cu, Fe, Mn, Ni, Pb, Tl, U, Zn) in seawater or brines from ore dumps by ICP-MS was established based on the complexation with sodium diethyldithiocarbamate-trihydrate (Na-DDTC) and separation on a phenyl column. The method was tested with seawater samples from the hydrothermal system of Axial Seamount, Juan de Fuca Ridge. The analytical results demonstrated the influence of hydrothermal activity on the concentration of Fe and Mn. Received: 2 December 1998 / Revised: 25 February 1999 / Accepted: 1 March 1999     

Determination of trace elements in marine plankton by inductively coupled plasma mass spectrometry (ICP-MS)

A method has been developed for the determination of 23 elements in marine plankton in which inductively coupled plasma (ICP) source mass spectrometry (MS) was used to quantify the elements in the solution after digestion in a mixture of hydrofluoric and nitric acids in sealed PTFE vessels in a microwave field. The procedure was validated by the analysis of a standard reference soil (SRM 2709 San Joaquin Soil) and a standard reference fresh water plankton (CRM 414). The method was applied to the analysis of several marine plankton samples grown under controlled conditions including several whose growth media had been enriched with selenium. Matrix induced signal suppressions and instrumental drift were corrected by internal standardization. The suitabilities of germanium, indium, rhodium, scandium and yttrium as internal standard elements were evaluated. Neither scandium nor yttrium could be used due to the presence of these elements in the samples, germanium was used for the determination of As, Co, Cu, Fe, Ni, Se, Si and Zn, indium was used for Al, Ba, Ca, Eu, Sr, and Tl, and rhodium was used for Cd, Cr, Hg, Mg, Pb, Sb, Sn, and V. For Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Si, Sr, V, and Zn internal standardization did not completely compensate for the suppressive effect of the heavier elements and the solutions were diluted. However, for As, Ba, Cd, Co, Eu, Hg, Pb, Sb, Se, Sn and Tl, it was possible to obtain accurate results despite the 35–¶40% suppression in the signals. Isobaric overlap was only a problem in the cases of ⁴²Ca and ⁷⁸Se; ⁴⁴Ca and ⁷⁷Se, respectively, were used. Memory effects were only observed with Hg for which a nitric acid-sodium chloride solution was the most effective wash-out solution. The marine plankton samples were able to tolerate a higher concentration of Hg as the selenium concentration increased.     

Determination of trace elements in liquid aspartame sweeteners by ICP OES and ICP-MS following acid digestion

In order to determine inorganic constituents and contaminants in liquid aspartame sweeteners, different brands of this product were analyzed by ICP OES and ICP-MS. The samples were submitted to acid digestion and parameters such as internal standardization and wavelengths, in the case of ICP OES, and a recovery test were evaluated. The analytes studied were As, Ca, Cd, Co, Cu, K, Fe, Mg, Mn, Na, Ni, Pb, Se and Zn. Since there is not a certified reference material for sweeteners, the accuracy of the proposed method was evaluated by recovery tests and the values were in the range of 90–110% for the majority of the analytes. The detection limits for the elements determined by ICP OES were in the range 0.01 (Mn)– 2.0 (K) μg g⁻¹ while those determined by ICP-MS were 0.001 μg g⁻¹ for all the elements except Mn and As (0.002 μg g⁻¹). The relative standard deviations were below 12% for ICP OES and below 14% for ICP-MS determinations. The mean concentration of the elements detected by ICP OES (Ca, Fe, K, Mg, Na, and Zn) varied according to the brand. The other analytes, were determined by ICP-MS. For these elements, a significant variation in their concentrations was also found for different samples, except for Co and Ni. The use of both multielemental techniques allowed the evaluation of the inorganic composition and the rapid determination of several elements in aspartame sweeteners, with adequate accuracy.     

Graphite electrode lithium tetraborate fusion for trace element determination in bulk geological samples by laser ablation ICP-MS

A rapid, accurate and precise method is presented for rock sample preparation in bulk analysis by LA-ICP-MS. Sample preparation is performed by lithium tetraborate fusion using an apparatus consisting of a 12 V (400 A) power source coupled with graphite electrodes utilized as crucibles. It allows analyzing few mg of powdered rock and, therefore, it could be useful in the case of low sample availability. An automated analytical protocol that allows determination of 25 elements (Ga, Rb, Sr, Y, Zr, Nb, Ba, rare earth elements, Hf, Ta, Pb, Th, and U) in 24 samples is also presented. Figure of merits related to the complete analytical protocol (sample preparation as fusion beads and LA-ICP-MS analyses) are estimated on five reference materials (USGS BCR2, USGS AGV2, USGS GSP2, CRPG ACE, and USGS RGM1) ranging from basaltic to rhyolitic in composition. The limits of detection range from c.a. 0.1 μg·g⁻¹ for Rb to 0.0007 μg·g⁻¹ for U. Precision is better than 10% for all elements with concentrations above 2 μg·g⁻¹, except for Pb (∼15%). Precision values raise to c.a. 15% for elements in concentration close to the limits of detection. Accuracies are better than 12% for all elements.     

Determination of trace elements in marine plankton by inductively coupled plasma mass spectrometry (ICP-MS)

A method has been developed for the determination of 23 elements in marine plankton in which inductively coupled plasma (ICP) source mass spectrometry (MS) was used to quantify the elements in the solution after digestion in a mixture of hydrofluoric and nitric acids in sealed PTFE vessels in a microwave field. The procedure was validated by the analysis of a standard reference soil (SRM 2709 San Joaquin Soil) and a standard reference fresh water plankton (CRM 414). The method was applied to the analysis of several marine plankton samples grown under controlled conditions including several whose growth media had been enriched with selenium. Matrix induced signal suppressions and instrumental drift were corrected by internal standardization. The suitabilities of germanium, indium, rhodium, scandium and yttrium as internal standard elements were evaluated. Neither scandium nor yttrium could be used due to the presence of these elements in the samples, germanium was used for the determination of As, Co, Cu, Fe, Ni, Se, Si and Zn, indium was used for Al, Ba, Ca, Eu, Sr, and Tl, and rhodium was used for Cd, Cr, Hg, Mg, Pb, Sb, Sn, and V. For Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Si, Sr, V, and Zn internal standardization did not completely compensate for the suppressive effect of the heavier elements and the solutions were diluted. However, for As, Ba, Cd, Co, Eu, Hg, Pb, Sb, Se, Sn and T1, it was possible to obtain accurate results despite the 35-40% suppression in the signals. Isobaric overlap was only a problem in the cases of 42Ca and 78Se; 44Ca and 77Se, respectively, were used. Memory effects were only observed with Hg for which a nitric acid-sodium chloride solution was the most effective wash-out solution. The marine plankton samples were able to tolerate a higher concentration of Hg as the selenium concentration increased.     

Analytical investigations of tree rings by laser ablation ICP-MS

Laser sampling inductively coupled plasma mass spectrometry has been used for the quantitative determination of trace elements to characterize annual growth rings of trees. The elements studied are Mg, Al, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba, Tl, Pb, Bi and U. Cellulose mixed with multielement standard solution pressed into pellets were used for the calibration. Using internal standardization with ¹²C the precision is typically better than 10% relative standard deviation. The limits of detection were limited by the purity of the cellulose. Analytical figures of merit and the analytical results are discussed in terms of environmental analysis.     

电感耦合等离子体质谱法测定人尸体10种器官组织样品中15种痕量稀土元素的研究

采用ICP MS法对人尸体 1 0种器官组织样品中痕量稀土元素测定进行了研究 ,选择了最佳仪器工作参数 ,用铑 (Rh)为内标元素补偿基体效应和灵敏度漂移 ,检出限为 0 .0 0 5 ( 89Y)～ 0 .0 2 3( 172 Yb)ng mL ,肝样品的加标回收率为 81 %～ 1 1 8% ,相对标准偏差为 1 .6%～ 1 4%。在严格质量控制的基础上用HNO3 HClO4混合酸消解样品 ,不须分离富集 ,直接对人尸体的肺、肝、骨、甲状腺、小肠、胃、肌肉、肾、脾和心中 1 5种痕量稀土元素进行测定。     

Quantitation methods using laser ablation ICP-MS

Laser Ablation ICP-MS offers the capability of direct analysis of conductive and non-conductive samples. However the quantitation capabilities of LA-ICP-MS are often questioned. In order to qualify the term quantitation, different methods, appropriate for laser ablation, are discussed. Measurements on different sample matrices were performed both semiquantitatively and quantitatively using standards with the same matrix. Additionally, the use of an internal standard, a minor isotope of the matrix element or a known concentration of a trace or a minor element can be selected as an aid to quantitation. In cases where there is no certified element concentration available, a user value for the LA-ICP-MS sensitivity can be chosen. These different methods of quantitation are compared and the rationale behind each approach is discussed.