Multielement analysis of whole blood by high resolution inductively coupled plasma mass spectrometry

An analytical method using double focusing sector field inductively coupled plasma mass spectrometry (ICP-SMS) for rapid simultaneous determination of 50 elements in digested human blood is described. Sample preparation consisted of microwave digestion with nitric acid followed by dilution with ultrapure water. The importance of controlling possible contamination sources at different sample preparation and analysis stages in order to achieve adequate method detection limits (MDL) is emphasised. Correction for matrix effects was made using scandium, indium and lutecium as internal standards. Accuracy of the data for elements suffering from spectral interferences was improved by applying either a high resolution capability of the ICP-SMS or mathematical corrections. Different approaches for accuracy assessment in blood analysis are evaluated. Additional information on trace elements concentration in selected blood reference materials is given. The between-batch precision was assessed from replicate analysis (including sample preparation) of reference materials and was better than 10% RSD for 21 elements and better than 30% RSD for 36 elements under consideration. A statistical summary for results obtained for 31 blood samples from non-exposed subjects is presented. The majority of elements tested was found in the samples at concentrations higher than MDL.     

Capabilities of high resolution inductively coupled plasma mass spectrometry for trace element determination in plant sample digests

The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to those obtained by quadrupole systems (ICP-QMS) and reach the fg mL^–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than 20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift. Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998     

Capabilities of high resolution inductively coupled plasma mass spectrometry for trace element determination in plant sample digests

The analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of plant sample digests was evaluated using double focusing sector field ICP-MS (ICP-SMS). Instrumental detection limits of ICP-SMS are superior to those obtained by quadrupole systems (ICP-QMS) and reach the fg mL^–1 range for elements with high m/z ratios. Matrix effects caused by a plant digest after sample preparation resulting in 200-fold dilution were found to be negligible. The usefulness of high mass resolution for overcoming some spectral interferences is demonstrated. Mathematical correction possibilities could be necessary to improve accuracy. The concentrations of more than 20 elements can be determined in 5 min and only one internal standard is necessary to correct for instrumental drift. Received: 30 March 1998 / Revised: 4 May 1998 / Accepted: 16 May 1998     

X射线荧光光谱法测定地质样品中的硫和氟

采用粉末压片制样-X射线荧光光谱法研究地质样品中硫(S)和氟(F)元素的快速测定方法。通过分级过筛实验优化确定样品粒度,探讨样品粒度对测定结果的影响,并进行实际样品和标准物质验证。结果显示,样品粒度为85μm时,经实际样品和标准物质验证,测定结果与化学值和标准认定值相符,且相对标准偏差(RSD)均小于2%。方法具有准确度高、检出限好、测试范围宽、简便快速等优点,能确保样品分析结果的准确性,实现了地质样品中S和F的快速测定。     

X射线荧光光谱法在电气石标准物质均匀性检验中的应用

采用粉末压片–X射线荧光光谱法对电气石标准物质候选物的均匀性进行检验。选择Si,Al,Mg,Fe,Ca,Na等6个元素作为检验元素,样品以随机方式进行测量,根据单因素方差分析的F值和测定值的相对标准偏差(RSD)判定样品的均匀性,并计算了检测方法的误差和样品不均匀误差。结果表明,方差检验的F计算值在0.80~1.93之间,小于F临界值1.96,测定结果的相对标准偏差小于0.9%;检测方法相对标准偏差和样品不均匀度(以RSD表示)均小于0.5%,说明制备的电气石标准物质候选物具有良好的均匀性。通过公式计算,确定最小取样量为200 mg。该方法无需湿法分解样品,绿色环保,简便快速,测定结果精密度高。     

Determination of metal concentrations in lichen samples by inductively coupled plasma atomic emission spectroscopy technique after applying different digestion procedures

Three digestion procedures have been tested on lichen samples for application in the determination of major, minor and trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn) in lichen samples collected in Aegean Region of Turkey by inductively coupled plasma atomic emission spectrometer (ICP-AES). The acid mixture of concentrated HNO₃, H₂O₂ and HF were used. The instrument was optimized using lichen matrix considering RF power, nebulizer pressure, auxiliary flow rate and pump rate. The accuracy of the overall analyses was first estimated by analysis of two certified reference materials. Good agreement between measured and reference values were found for almost all elements. As the second way of determining the accuracy, results obtained from independent analytical techniques (ICP-AES and instrumental neutron activation analysis (INAA)) were compared for all elements by analyzing real samples. Correlation coefficients of two techniques for the elements ranged between 0.70 (Mg) and 0.96 (Fe). Among the three digestion systems, namely microwave, open vessel and acid bomb, microwave digestion system gave the best recovery results. The method detection limit (MDL) was computed using reagent blanks of microwave digestion system since it provides cleaner sample preparation. Detection limit is adequate for all elements to determine the elements in lichen samples. The precision was assessed from the replicate analyses of reagent blanks of microwave digestion system and was found to be less than 1.5% relative standard deviation (R.S.D.).     

Multielement analysis of coal by ICP techniques using solution nebulization and laser ablation

The combination of inductively coupled plasma atomic emission spectrometry and high resolution inductively coupled plasma mass spectrometry for the determination of 70 elements in coal were studied. Four microwave-assisted digestion procedures with different dissolution mixtures (nitric and hydrofluoric acids, aqua regia and hydrogen peroxide), lithium metaborate fusion with and without previous sample ashing as well as direct sampling by laser ablation (LA) have been tested. Examples of spectral interferences are given and different correction procedures are discussed. Detection limits in the low ng g(-1) range were obtained for most of the elements investigated by using high-purity reagents and by taking special care to prevent sample contamination during preparation. The precision was assessed from replicate analysis (including sample preparation) of coal samples and was found to be, as average values far all elements, 4-5% RSD and 10-15% RSD for procedures including sample digestion and LA sampling, respectively. The accuracy of the overall analytical procedures was estimated by analysis of certified reference materials and of a coal sample obtained from the Interlab Trace round robin test. Among the dissolution mixtures tested, the combination of nitric and hydrofluoric acids with hydrogen peroxide provide the best agreement with certified, recommended, literature-compiled or consensus values, though fusion is necessary to obtain quantitative recoveries for Si, Cr, Hf, W, Zr, Y. In general, results obtained by LA fall within +/-20% of those obtained after digestion.     

X射线荧光光谱法测定锡矿石中锡

本文采用向样品中加入硼酸来降低基体效应,加入氧化镧来稳定样品总质量吸收系数,建立固体粉末压片制样-X射线荧光光谱法测定锡矿石中锡含量的方法。通过将标准物质按一定比例混合配制和选取部分自制标样来补充标准物质样品,以解决锡矿石标准物质样品缺乏的问题。实验优化了稀释比,确定了以最佳稀释比为m（矿物质样品）:m（硼酸）：m（氧化镧）=1.0:2.0:0.5。在最优的实验条件下,Sn的荧光强度（kcps）与Sn浓度CSn呈良好的线性关系,R2=0.9989。方法中锡元素的最低检出限为0.005 %,测定范围在0.015 %-4.47 %之间。样品的混合均匀性实验表明各元素测定结果的相对标准偏差（RSD,n=6）在1.0 %-2.64 %之间。对3个不同含量段的物质进行测定来验证方法的准确度和精密度,准确度分别为0.0082-0.0367,均小于0.04,精密度分别为0.39 %-1.18 %,均小于8.0 %,准确度和精密度均符合地质样品分析规范要求。测定值均在误差范围内,各组分测定结果的相对标准偏差（RSD,n=11）在1.20 %以下。粉末压片-X射线荧光光谱法测定锡矿石中锡含量具有分析范围广、分析时间短、重现性好、精度高且操作简单等特点。能应用于地质、环境、材料等领域。     

Application of an ETV-ICP system for the determination of elements in human hair

When determining element contents in hair samples without sample digestion it is necessary to analyze large sample volumes in order to minimize problems of inhomogeneity of biological sample materials. Therefore an electrothermal vaporization system (ETV) is used for solid sample introduction into an inductively coupled plasma (ICP) for the determination of matrix and trace elements in hair. This paper concentrates on the instrumental aspects without time consuming sample preparation. The results obtained for optimization tests, ETV operating parameters and ICP operating parameters, are shown and discussed. Standard additions are used for calibration for the determination of Zn, Mg, and Mn in human hair. Studies including reproducibility and detection limits for chosen elements have been carried out on certified reference materials (CRMs). The determination of reproducibility (relative standard deviation (RSD) of n = 10) and detection limits (DLs) of Zn (RSD < 8.5%, DL < 0.8 μ g⁻¹), Mn (RSD < 14.1%, DL < 0.3 μ g⁻¹), and Mg (RSD < 7.4%, DL < 6.6 μ g⁻¹) are satisfactory. The concentration values found show good agreement with the corresponding certified values. Further sample preparation steps, including hair sampling, washing procedure and homogenization for hair, relating to measurements of real hair samples are described.     

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.     

粉末压片-X-射线荧光光谱法分析砂岩型铀矿制样中粘结剂用量的探讨

由于砂岩型铀矿的成矿特性,样品粉末的内聚力小,采用直接压片法有时难以成型,样片表面常见裂纹,上机测量易碎裂。混合压片法适应性强,制样成功率高,但常见的问题是样品经粘结剂稀释会影响元素的检出限及结果的准确性。本文对粉末压片-X射线荧光光谱法测定砂岩型铀矿地质样品时,前期制样中添加粘结剂的比例进行了研究。试验按照不同比例在铀矿石标准物质GBW04101、GBW04102中添加粘结剂,在扫描电镜下观察到随着粘结剂用量的增加样片表面的光滑度及致密度都呈上升趋势,在X-射线荧光光谱仪上对主量元素进行测定后发现X射线强度在粘结剂添加量大于0.2 g时明显下降,经与GBW04101、GBW04102标准值进行对比后优选出粘结剂与样品的最佳比例为1：20,在此比例下制成的样片光滑平整,不易碎裂,用粉末压片-X射线荧光光谱法进行测定,标准物质测定结果的相对误差为0.56%～6.76 %,相对标准偏差(RSD,n=12)为0.013 %～7.68 %,均达到了《地质矿产实验室测试质量管理规范》DZ/T 0130-2006的要求。本文为粉末压片-X射线荧光光谱法分析砂岩型铀矿地质样品提供了可靠的实验参考依据。     

改进的氧瓶燃烧法结合电感耦合等离子体质谱快速测定茶叶样品中的稀土元素含量

建立了电感耦合等离子体质谱法快速测定茶叶中Y~Lu共15种稀土元素的新方法,样品处理基于改进的氧瓶燃烧法,以涂覆甘油的石英布代替滤纸作为引燃和燃烧载体,在500 mL容积燃烧瓶中实现了0.1 g样品量的有氧完全燃烧。系统优化了样品处理关键参数,以5 mL 4％ HNO3+1％ HF(V/V)组合试剂超声提取燃烧残渣1 min,稀土元素回收率大于90％,样品总处理周期小于3 min。6次样品平行测定值的相对标准偏差(RSD)在2.7％~5.5％之间,方法检出限(3σ)在0.001~0.006 mg/kg之间。采用本方法对3种茶叶标准参考物质进行分析,测定结果和标准值吻合良好。     

Elemental analysis of airborne dust samples with TXRF: Comparison of oxygen-plasma ashing on sapphire carriers and acid digestion for sample preparation

The concentrations of 13 elements (As, Ca, Co, Cd, Cr, Fe, Ga, Ni, Pb, Pt, Ti, V and Zn) were determined in air particulate matter using total reflection X-ray fluorescence spectrometry (TXRF). For silicon analysis synthetic sapphire was chosen as a new sample carrier material – it is silicon-free, resistant to oxygen-plasma, microwaves and concentrated acids. The dust samples were collected on cellulose acetate filters. The decomposition of the filters was carried out by oxidation in a microwave-generated low-pressure oxygen-plasma directly on the TXRF sample carriers. The recovery of the investigated elements was verified with the standard reference material SRM 1648 (urban particulate matter) and ranged from 90 to 97%. The oxygen-plasma method was compared with conventional sample preparation by acid digestion. Received: 9 April 1999 / Revised: 18 May 1999 / Accepted: 3 June 1999     

Elemental analysis of airborne dust samples with TXRF: Comparison of oxygen-plasma ashing on sapphire carriers and acid digestion for sample preparation

The concentrations of 13 elements (As, Ca, Co, Cd, Cr, Fe, Ga, Ni, Pb, Pt, Ti, V and Zn) were determined in air particulate matter using total reflection X-ray fluorescence spectrometry (TXRF). For silicon analysis synthetic sapphire was chosen as a new sample carrier material – it is silicon-free, resistant to oxygen-plasma, microwaves and concentrated acids. The dust samples were collected on cellulose acetate filters. The decomposition of the filters was carried out by oxidation in a microwave-generated low-pressure oxygen-plasma directly on the TXRF sample carriers. The recovery of the investigated elements was verified with the standard reference material SRM 1648 (urban particulate matter) and ranged from 90 to 97%. The oxygen-plasma method was compared with conventional sample preparation by acid digestion. Received: 9 April 1999 / Revised: 18 May 1999 / Accepted: 3 June 1999     

Using dried-droplet laser ablation inductively coupled plasma mass spectrometry to quantify multiple elements in whole blood

This paper describes a simple procedure for the direct analysis and determination of multiple elements in dried blood samples on a filter membrane using laser ablation coupled with inductively coupled plasma mass spectrometry (LA-ICP-MS). With this technique, we simultaneously quantified 13 elements in whole blood: Be, Mn, Co, Ni, Tl, Bi, Sb, Pb, Cu, Zn, Ba, Mg, and Cd. The measured accuracies was in agreement with the Seronorm CRM certified values, except for Mn, Zn, Ba and Cd, which presented absolute differences higher than the expanded uncertainty for these elements. The within-run precision was less than 5.7% (relative standard deviation, RSD), except for the analyses of Be, and Mn (8.6% and 11.1%, respectively). The reproducibility (between-run precision) was calculated in terms of the RSD obtained for 12 analyses (i.e., four replicates of each sample in three analytical runs). Apart from Be, Mn, and Zn, the reproducibilities of all the elements listed above ranged between 4.0% and 8.5%. In contrast, for Cd, the concentration obtained was significantly different from the certified value; analyses of this element exhibited low reproducibility. Applying the matrix-matched calibration method, the accuracy for Cd measured was in agreement with both SRM966 and BCR 635; thus, matrix-matched calibration is a practical means of overcoming matrix-enhancement effects for the quantification of Cd. Sample throughput (ca. 5 min per sample) made it possible to rapidly screen a larger number of samples relative to other techniques that require time-consuming sample preparation steps (e.g., removal of a portion of the solid sample or digestion).     

Fused glass sample preparation for quantitative laser-induced breakdown spectroscopy of geologic materials

Laser-induced breakdown spectroscopy is a powerful analytical method, but LIBS is subject to a matrix effect which can limit its ability to produce quantitative results in complex materials such as geologic samples. Various methods of sample preparation, calibration, and data processing have been attempted to compensate for the matrix effect and improve LIBS precision. This study focuses on sample preparation by comparing fused glass as a preparation for powdered material to the more commonly used method of pressing powder into pellets for LIBS analysis of major elements in complex geologic materials. Pelletizing powdered material is a common and convenient method for preparing samples but problems with the physical matrix brought on by inconsistencies in the homogeneity, density, and laser absorption, coupled with the chemical matrix problem lead to spectral peak responses that are not always consistent with the absolute concentration of representative elements. Twenty-two mineral and rock samples were analyzed for eight major oxide elements. Samples were prepared under both glass and pellet methods and compared for internal precision and overall accuracy. Fused glass provided a more consistent physical matrix and yielded more reliable peak responses in the LIBS analysis than did the pressed pellet preparation. Statistical comparisons demonstrated that the glass samples expressed stronger separability between different mineral species based on the eight elements than for the pressed pellets and showed better spot-to-spot repeatability. Regression models showed substantially better correlations and predictive ability among the elements for the glass preparation than did those for the pressed pellets.     

Determination of Trace Elements in Different Powdered Samples by Atomic Emission Spectrometry with Spectral Excitation in a Two-Jet Arc Plasmatron

The effects of operating parameters and easily ionized additives on the analytical signal in the region before the confluence of plasmatron jets were studied. It was shown that the effective atomic excitation temperature in this region is independent of the concentration of NaCl (0–50%) in the graphite powder. A method was proposed for the direct atomic emission determination of trace elements in powdered samples. In this method, multielement analysis of various samples, such as graphite concentrates of trace impurities, soils, bottom sediments, plants, and humic acids can be performed under unified conditions using a unified set of reference samples without sample mineralization and dissolution. At the stage of sample preparation, a finely divided sample is mixed with a spectroscopic buffer (graphite powder doped with NaCl). The detection limits for several dozen elements in their direct determination varied from 10^–6 to 10^–4 wt % at a relative standard deviation (RSD) of no worse than 15%.     

交流电弧发射光谱法测定地球化学样品中的高含量锡

建立了交流电弧发射光谱法测定化学样品中锡的方法。以氧化锌、氟化钠、硫粉为缓冲剂,改善元素蒸发行为;以锗为内标,样品与缓冲剂比例为1∶1。根据不同含量的锡选择不同级别灵敏线进行分析,采取内标法,建立浓度与相对强度之间的线性关系,计算出样品中锡的含量。实验中可以将锡的分析上限提高到x%,同时避免由稀释样品带来的分析误差。方法相对标准偏差(RSD,n=12)小于7%,测定了国家一级地球化学标准物质,结果与标准值相符。     

Determination of minor elements in steelmaking flue dusts using laser ablation inductively coupled plasma mass spectrometry

Element determination in solid waste products from the steel industry usually involves the time-consuming step of preparing a solution of the solid. Laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to the analysis of Cr, Ni, Cu, As, Cd and Sn, elements of importance from the point of view of their impact on the environment, in electric arc furnace flue dust (EAFD). A simple method of sample preparation as pressed pellets using a mixture of cellulose and paraffin as binder material was applied. Calibration standards were prepared spiking multielement solution standards to a 1:1 ZnO + Fe₂O₃ synthetic matrix. The wet powder was dried and mechanically homogenised. Quantitative analysis were based on external calibration using a set of matrix matched calibration standards with Rh as a internal standard. Results obtained using only one-point for calibration without matrix matched, needing less time for standardization and data processing, are also presented. Data are calculated for flue dust reference materials: CRM 876-1 (EAFD), AG-6203 (EAFD), AG-6201 (cupola dust) and AG-SX3705 (coke ashes), and for two representative electrical arc furnace flue dusts samples from Spanish steelmaking companies: MS-1 and MS-2. For the reference materials, an acceptable agreement with certificate values was achieved, and the results for the MS samples matched with those obtained from conventional nebulization solutions (CN). The analytical precision was found to be better than 7% R.S.D. both within a single pellet and between several pellets of the same sample for all the elements.