Interferometric measurements of spectral line widths emitted by an inductively coupled plasma

Line widths of fifteen spectral lines of ten elements introduced into an inductively coupled plasma (ICP) have been measured with a Fabry-Pcrot interferometer. Instrumental broadening is estimated by measuring the line widths emitted by hollow-cathode lamps and assuming their actual profiles as purely Gaussian with Doppler widths at 400 K. For correction of the experimental widths of lines emitted by the ICP, actual profiles of the lines are assumed to be purely Gaussian as a first approximation. The calculated actual widths range from 0.0015 to 0.0051 nm. Values of the a-paramctcr of the Voigt profile are estimated by assuming the Doppler temperature of the plasma to be 5000 K. Most of the lines emitted by the ICP have a-values in a range between 0.2 and 0.7. The fact reported previously that ICP lines suffer from less collisional broadening than lines excited in flames is supported.     

Observation of spectral line profiles emitted by an inductively coupled plasma—I.: On the wavelength shift of spectral lines

Profiles of 16 spectral lines stemming from 8 elements (Ar, Na, Cu, Sr, Cd, Ba, Mg and Li) emitted by an inductively coupled plasma (ICP) have been observed and measured with a pressure-scanning Fabry-Perot interferometer. In the process of profile observations, we have found wavelength shifts of spectral lines in an ICP and for the first time studied this phenomenon quantitatively and systematically in a spectrochemical source. The profiles of spectral lines emitted by the ICP have been compared with those emitted by hollow cathode lamps. The magnitude of the wavelength shift to the red or the blue varied more or less with the plasma conditions, observation position and the concentration of a concomitant, cesium. In the present work the observed line profiles were not deconvoluted for the apparatus profiles. Typically the order of magnitude of the wavelength shift measured for spectral lines that show large shifts at an observation height of about 4 mm in an “analytical” ICP is n × 10^?3 nm, where n is about 4 for Ar I 427.2 nm and about 1 for Cu I 521.8 nm and Sr II 430.5 nm. With regard to the wavelength shift, several trends and/or regularities were found. The Stark effect is considered as the main cause of the phenomena.     

Iron spectrum in the 200–300 nm range emitted by an inductively coupled argon plasma

In order to make a comparison with the available wavelength tables, the iron spectrum has been studied in the 200–300 nm range in ICP-AES. About a hundred lines have been found that have, so far, been unreported. Examples of spectral interferences and conclusions on the field covered by the various tables are given.     

Determination of trace elements in granites by inductively coupled plasma mass spectrometry

Proposed is a simple and reliable method for the dissolution of granite and the determination of 38 elements by inductively coupled plasma mass spectrometry. One hundred milligrams of sample are digested with 1 ml of HF and 0.5 ml of HNO(3) in screw top PTFE-lined stainless steel bombs at 190 degrees C for 12 h. Insoluble residues are dissolved using 8 ml of 40% HNO(3) (v/v) heated to 110 degrees C for 3 h. Six granite standard reference materials (GSR-1, JG-2, G-2, NIM-G, SG-3, SG-1a) were studied. Analytical calibration was accomplished using aqueous standard solutions. Rhodium was used as an internal standard to correct for matrix effects and instrument drift. We report data for: Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cs, Ba, Hf, Ta, W, Pb, Th, U and 14 of the rare earth elements. The recoveries for most of these elements in granite ranged from 90 to 110%.     

Application of prominent spectral lines in the 125-180 nm range for inductively coupled plasma optical emission spectrometry

A new axially viewed ICP optical emission spectrometer featuring an argon-filled optic and CCD detectors was evaluated for the application of prominent spectral lines in the 125-180 nm range. This wavelength range was investigated for several analytical applications of inductively coupled plasma optical emission spectrometry (ICP-OES). There are different advantages for the application of spectral lines below 180 nm. A number of elements, such as Al, Br, Cl, Ga, Ge, I, In, N, P, Pb, Pt, S and Te, were found to have the most intense spectral lines in the wavelength range from 125-180 nm. Compared with lines above 180 nm higher signal-to-background ratios were found. Low limits of detection using pneumatic nebulization of aqueous solutions for sample introduction were calculated for Al II 167.080 nm (0.04 microg L(-1)), Br I 154.065 nm (9 microg L(-1)), Cl I 134.724 nm (19 microg L(-1)), Ga II 141.444 nm (0.8 microg L(-1)), Ge II 164.919 nm (1.3 microg L(-1)), II 142.549 nm (13 microg L(-1)), In II 158.583 nm (0.2 microg L(-1)), P I 177.500 nm (0.9 microg L(-1)), Pb II 168.215 nm (1.5 microg L(-1)), Pt II 177.709 nm (2.6 microg L(-1)), S I 180.731 nm (1.9 microg L(-1)) and Te I 170.00 nm (4.6 microg L(-1)). Numerous application examples for the use of those lines and other important spectral lines below 180 nm are given. Because of fewer emission lines from transition elements, such as Fe, Co, Cr, lines below 180 nm often offer freedom from spectral interferences. Additional lines of lower intensity for the determination of higher elemental concentrations are also available in the vacuum ultraviolet spectral range. This is specially useful when the concentrations are not in the linear range of calibration curves obtained with commonly used lines.     

Determination of rare-earth elements in uranium-bearing materials by inductively coupled plasma mass spectrometry

A novel and simple analytical procedure has been developed for the trace-level determination of lanthanides (rare-earth elements) in uranium-bearing materials by inductively coupled plasma sector-field mass spectrometry (ICP-SFMS). The method involves a selective extraction chromatographic separation of lanthanides using TRU™ resin followed by ICP-SFMS analysis. The limits of detection of the method proposed is in the low pg g⁻¹ range, which are approximately two orders of magnitude better than that of without chemical separation. The method was validated by the measurement of reference material and applied for the analysis of uranium ore concentrates (yellow cakes) for nuclear forensic purposes, as a potential application of the methodology.     

Determination of major and minor elements in silicates by inductively coupled plasma emission spectrometry

A simple rapid method for the determination of major and minor elements in silicates is reported. Powdered sample (50 mg) is treated with hydrochloric and hydrofluoric acids in a small sealed Teflon vessel. After addition of boric acid, silicon, aluminium, iron, titanium, manganese, calcium, magnesium, sodium, and potassium are determined by inductively coupled plasma emission spectrometry. The method is satisfactory for a variety of standard silicate materials.     

混凝土中重金属元素溶出量的质谱分析

利用带八极杆碰撞/反应池和屏蔽炬技术的电感耦合等离子体质谱直接测定混凝土中Cr,Mn,Ni,Cu,Zn,As,Cd,Sn,Sb,Pb等多种重金属元素的溶出量。通过向碰撞池中引入氢气和氦气消除多元素分子离子的干扰,以50μg/L的Ge,In,Tb为内标元素校正基体干扰和漂移。10种待测元素的检出限为0.001～0.033μg/L,相对标准偏差为0.85%～2.8%,样品的加标回收率在91.1%～103.9%之间。     

Determination of trace elements in residual oil by high-resolution inductively coupled plasma mass spectrometry

An analytical method using high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 20 elements, including Na, Mg, Al, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, and Pb elements, in residual oil was described. The sample was dissolved in HNO₃ by microwave digestion, and then the above 20 elements in the solution were analyzed directly by HR-ICP-MS. Most of the spectral interferences could be avoided by measuring in the high-resolution mode. The matrix effect caused by the sample-digesting solution and corrected by Sc, Rh, and Bi as the internal standard elements was studied in detail. The optimum condition of the determination was also tested and discussed. The result showed that the detection limits of the method were in the range of 0.014 to 11.6 μg L⁻¹; the relative standard deviation was less than 3.8% and recoveries in the samples were in the range of 88.4% to 108.0%. This method can be used to determine the trace elements in residual oil with the features of accurate, rapid, and convenient determination.     

电感耦合等离子体质谱法测定高纯金中铝、砷、铋、铬、铁、铅、锑、硒、碲、铱痕量元素

建立了微波消解-内标法-标准加入-ICP-MS法测定高纯黄金中铝、砷、铋、铬、铁、铅、锑、硒、碲、铱等痕量元素的分析方法.从试样溶解方式、内标元素及同位素的选择、仪器检测模式的优化及降低基体抑制效应等方面进行优化.实验加标回收率为99.5％ ～110％,相对标准偏差(RSD)为0.050％ ～6.5％.实验的准确度和精...     

电感耦合等离子体质谱法测定花生中34种元素

建立了微波消解-碰撞/反应池(ORS)电感耦合等离子体质谱仪(ICP-MS)同时测定花生中的Na、Mg、Ca、Fe、Se、Mo和稀土元素等34种元素的分析方法。样品经微波消解后,在线加入内标元素45Sc、72Ge、103Rh、115In和209Bi消除基体效应,应用碰撞反应池技术,以4.5 mL/min流速的氦气作为碰撞反应气,有效消除多原子离子产生的质谱干扰。各元素的检出限为0.0003～17.37ng/mL,相对标准偏差(RSD)低于2.9%;标准物质的测定值均在标准值范围内,结果令人满意。该方法可用于花生中多种元素的同时测定。     

电感耦合等离子体质谱(ICP-MS)法测定锰矿冶炼烟尘中多种重金属元素

为了准确测定锰矿冶炼烟尘中重金属元素的含量,为锰矿冶炼过程中监测和评价环境影响提供有力的数据支撑,采用HCl+HNO₃+HClO₄+HF消解体系对试样进行前处理,通过选用合适的内标溶液消除测定中的非质谱干扰,采用碰撞池模式和编辑校正方程消除质谱干扰,从而建立了电感耦合等离子体质谱法测定锰矿冶炼烟尘中的Cr、Ni、Cd、Tl、Pb等多种重金属元素的方法。实验结果表明,各元素标准曲线的线性相关系数均大于0.999 9,方法检出限为0.007～0.094 mg/kg,样品测定的相对标准偏差(RSD,n=11)在0.43%～4.9%,样品加标回收率为93.8%～107%。方法具有操作简便、线性范围宽、检出限低、精密度高等优点,满足锰矿冶炼烟尘中Cr、Ni、Cd、Tl、Pb等多种重金属元素同时测定的要求。     

Determination of trace elements in plant materials by inductively coupled plasma optical emission spectrometry

The use of inductively coupled plasmas as spectrometric emission sources for the determination of Fe, Mn, Cu, Al, B and Zn in orchard leaves is investigated. The plasma is shown to be sufficiently sensitive for the direct determination of all of the above elements in solutions of the plant materials after a dry ashing procedure. Comparative values for the trace element concentrations by other analytical methods are given.     

电感耦合等离子体质谱测定富钴结壳中的稀土元素

采用封闭压力酸溶(HF+HNO3)消解样品,以Rh为内标,用电感耦合等离子体质谱测定富钴结壳中的稀土元素。用此方法对3个国家一级标准物质富钴结壳标样(GSMC-1,GSMC-2,GSMC-3)进行了多次测定,结果稀土元素的测定值与标准值相符,多次测定结果的相对标准偏差(RSD,n=5)在0.36%～4.0%之间,加标回收率为90%～106%。基于此方法,对6个富钴结壳样品进行了测定,显示富钴结壳样品中稀土元素的配分曲线与标准物质中稀土元素的配分模式一致。方法适用于富钴结壳样品的批量分析。     

Temperature and velocity distributions in an inductively coupled plasma

Computer simulations of inductively coupled plasma discharges (ICP) with flow patterns similar to those found in spectrochemical analysis were reported previously. In this investigation temperature and velocity distributions are measured under conditions which allow direct comparison with computer calculations for pure argon central gas flows without solution aerosols. Based upon these comparisons, a refined ICP gas flow model is proposed and its application provides agreement within experimental error between measured and calculated velocity and temperature profiles in most regions of the discharge.     

The use of concomitant elements to evaluate an Ar–N2 mixed-gas plasma by electrothermal vaporization inductively coupled plasma orthogonal time-of-flight mass spectrometry

The performance of an Ar–N₂ mixed-gas plasma was compared to an Ar plasma using electrothermal vaporization as a sample introduction source to an inductively coupled plasma orthogonal time-of-flight mass spectrometer. The effect of sample matrices NaNO₃ and Pd(NO₃)₂ on a multi-element solution was investigated in mass amounts ranging from 0.1 to 5 μg of the metal matrix (e.g., Na and Pd). Addition of 2% N₂ to the outer plasma gas of an Ar plasma reduced signal suppressions observed in the presence of high concentrations of Na and Pd at the expense of a large reduction in analyte sensitivity (ca. 83%). Signal profiles indicate that suppression may be caused, in part, by space charge effects that are dependent on the ion density of analyte and matrix ions. By reducing the magnitude of the signal from the N₂-free plasma by repositioning the torch away from the sampling cone, comparable immunity to excess matrix was observed when compared to a plasma with N₂ included in the outer plasma gas.     

Determination of ultra-trace rare earth elements in chondritic meteorites by inductively coupled plasma mass spectrometry

A method for the direct determination of ultra-trace rare earth elements (REE) in seven Chinese chondritic meteorites by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Samples were digested with a mixture of HF+HNO₃ acids in Teflon pressure bomb. The accuracy and precision of the method were assessed by the analysis of four standard reference materials including one chondrite (Allende) and three basalts (BCR-1, BHVO-1 and W-2), the results obtained in this study agree quite well with the recommended values. The reproducibilities (expressed as RSD) of samples were less than 5%.     

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.