电感耦合等离子体原子发射光谱(ICP-AES)法测定银钯合金中银和钯

建立健全测定银钯合金中银和钯含量的检测方法,对实现银钯合金中银和钯的高精度分析以及资源化利用有着重大意义。实验建立了电感耦合等离子发射光谱法(ICP-AES)同时测定银钯合金中银钯含量的分析方法。实验采用先加入10mL硝酸,再加入50mL过量盐酸混合,采用加热套混合消解银钯合金并混合定容在酸性浓度为18%HCl为介质中,然后通过控制不同的HCl浓度来测定银钯含量。实验结果表明：银的最佳检测酸性浓度为18%、钯的最佳酸性检测浓度为4%且该方法的加标回收率在97%-100%之间,相对标准偏差(RSD, n=10)小于2%。     

A helium inductively coupled plasma for atomic emission spectrometry

An annular helium inductively coupled plasma (He ICP) was generated at atmospheric pressure. No external cooling was used to stabilize the plasma. Aqueous solution was injected into the plasma without any difficulty. Preliminary results revealed that the annular He ICP was capable of exciting elements such as Cl and Br which possess high excitation energies. Atomic emission detection limits for Cl and Br were improved by factors of 63 and 34, respectively, as compared to the results obtained from the argon inductively coupled plasma. The excitation temperature of the annular He ICP (4180 K) was less than that of an Ar ICP (5570 K).     

电感耦合等离子体原子发射光谱法测定钛合金中锆

建立电感耦合等离子体原子发射光谱法(ICP-AES)测定钛合金中锆元素的含量。采用盐酸-氢氟酸-硝酸溶解钛合金样品,选择357.247 nm为锆的分析谱线,通过基体匹配法消除基体钛的干扰,以电感耦合等离子体原子发射光谱法测定钛合金中锆的含量。锆的质量分数在0%~0.4%范围内与光谱强度呈良好的线性关系,相关系数大于0.999,定量下限为0.21%。测定结果的相对标准偏差小于2%(n=11),样品加标回收率为99.0%~102.7%。该方法快速、准确,能够满足实际生产中钛合金样品的测定要求。     

电感耦合等离子体–原子发射光谱法同时测定铝合金中9种元素

建立电感耦合等离子体原子发射光谱同时测定铝合金中9种元素含量的方法。铝合金样品采用碱溶法预处理,以质量分数为40%的氢氧化钠溶液溶解,再用盐酸-硝酸混合酸酸化,然后用电感耦合等离子体原子发射光谱法同时测定样品中铁、硅、铜、镁、锰、锌、钛、镍、铬9种元素的含量。各元素的含量与对应的发射强度呈良好的线性关系,相关系数不小于0.9990;各元素检出限为0.0001%~0.0012%。应用该方法测定2个铝合金标准样品,测定结果与标示值一致,相对标准偏差为0.46%~2.14%(n=8)。将该法应用于试样测定时,加标回收率为92%~106%。该方法精密度和准确度高,操作简便、快速,适用于实验室铝合金多元素含量的检测。     

电感耦合等离子体原子发射光谱法测定钼镧合金中镧元素

采用盐酸-硝酸溶解钼镧合金样品,建立电感耦合等离子体原子发射光谱法（ICP-AES）测定钼镧合金中镧元素的分析方法,给出影响测量结果的不确定度分量。选择379.478nm为镧的分析谱线,通过基体匹配法消除基体钼的干扰。在优化条件下对钼镧合金样品进行测定,线性相关系数在0.999以上,定量下限为0.048%,测定结果的相对标准偏差（RSD,n=11）小于3%,回收率为93.00%~105.00%。该方法快速、准确,可以满足实际生产中钼镧合金样品的测定要求。     

Quality of calibration in inductively coupled plasma atomic emission spectrometry

Calibration is a crucial step during the whole analytical process. A procedure is suggested to assess the quality of linear regression used for the calibration graph, based on the use of confidence limits for the concentration, as the regression coefficient is not appropriate for this purpose. This procedure has been applied to inductively coupled plasma atomic emission spectrometry. It indicates that the use of only three standards should be discouraged because of unacceptably high confidence limits for the concentration. Moreover, use of weighted regression is more adequate in performing the least squares method and provides more constant confidence limits over the concentration range used to construct the calibration graph. This procedure could be easily added to any commercially available ICP system software.     

Problems,possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum,palladium and rhodium in samples with different matrix composition

The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g^− 1 were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts.     

On-line-sorption preconcentration and inductively coupled plasma atomic emission spectrometry determination of rare earth elements

The system for on-line microcolumn sorption preconcentration and inductively coupled plasma atomic emission spectrometry determination of 14 rare earth elements (REEs) is described. Aminocarboxylic sorbents of different structure are used. Preconcentration of REEs from the 20 ml of sample solution and elution with 210 μl of 1 mol l⁻¹ HCl results in an enrichment factor of 99. The detection limit of REEs is about n × 0.1 μg l⁻¹ (RSD 3–5%). The possibility of simultaneous REE determination in complicated solutions is demonstrated.     

Carbon-related matrix effects in inductively coupled plasma atomic emission spectrometry

In Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), it has been observed that the emission intensity of some atomic lines is enhanced or depressed by the presence of carbon in the matrix. The goal of this work was to investigate the origin and magnitude of the carbon-related matrix effects in ICP-AES. To this end, the influence of the carbon concentration and source (i.e. glycerol, citric acid and potassium hydrogen phthalate), the experimental conditions and sample introduction system on the aerosol characteristics and transport, plasma excitation conditions and the emission intensity of several atomic and ionic lines of a total of 15 elements has been studied. Results indicate that carbon related matrix effects do not depend on the carbon source and they become more severe when the amount of carbon loaded into the plasma increases, i.e., when using: (i) carbon concentrations higher than 5 g L^− 1; (ii) high sample uptake rates; and (iii) efficient sample introduction systems. Thus, when introducing carbon into the plasma, the emission intensity of atomic lines with excitation energies below 6 eV is depressed (up to 15%) whereas the emission intensity of atomic lines of higher excitation energies (i.e. As and Se) are enhanced (up to 30%). The emission intensity of the ionic lines is not affected by the presence of carbon. The origin of the carbon-related interferences on the emission intensity of atomic lines is related to changes in the line excitation mechanism since the carbon containing solutions show the same aerosol characteristics and transport efficiencies as the corresponding aqueous solutions. Based on the previous findings, a calibration approach for the accurate determination of Se in a Se-enriched yeast certified material (SELM-1) has been proposed.     

Direct determination of cadmium in urine by tungsten-coil inductively coupled plasma atomic emission spectrometry using palladium as a permanent modifier

Cadmium is determined in urine samples collected from patients with age-related diseases. The urine is simply diluted 1:1 with water and placed on a tungsten coil electrothermal vaporizer treated with 200 μg of a permanent Pd modifier. A straightforward vaporization program is used to deliver the Cd vapor to an inductively coupled plasma atomic emission spectrometer. A high resolution spectrometer and a charge coupled device detector provide spectra across a 4.8 nm window encompassing two separate Cd emission lines: 226.5 and 228.8 nm. The limit of detection is 0.2 μg/L at each wavelength, and the linear dynamic range spans three orders of magnitude. The accuracy as measured with a urine standard reference material is 94%. The Pd modifier continues to be effective even after 150 vaporization cycles. Direct analysis of urine with the Pd modifier using simple aqueous calibration solutions provides results that are comparable to those observed after a much more complex method: chelation, extraction, and internal standardization without the modifier. The mean concentrations found by the two techniques differ by only 9%. The permanent Pd modifier allows direct analysis of limited sample volumes with decreased risks of contamination.     

Modified Babington nebulizer for inductively coupled plasma atomic emission spectrometry.

A PTFE Babingtonnebulizer equipped with a hood was investigated for inductively coupled plasma atomicemission spectrometry in conjunction with a PTFE cyclone chamber, in order to nebulize various sample solutions containing high salts, hydrofluoric acid and/or suspended solid. A hood of 3 mmphi (nozzle side) - 5 mmphi (outlet side) and 6 mm in length gave a comparable or higher sensitivity compared to a system with a commercially available concentric nebulizer and a glass cyclone chamber. Moreover, the present nebulizer was fully interchangeable with a concentric one at normal argon pressure, attaining sufficient stability, a short wash-out time and good nebulizing of high matrices solutions. The present system was successfully applied to the determination of trace impurities in highly pure silica powders.     

Interface for capillary electrophoresis coupled with inductively coupled plasma atomic emission spectrometry.

A modified concentric nebulizer was used as the interface to couple capillary electrophoresis (CE) to inductively coupled plasma atomic emission spectrometry (ICP-AES). The CE capillary replaces the central tube of the concentric nebulizer. The tip of the nebulizer tapers slowly to allow uncertainty in the position of the capillary. A platinum wire was inserted into the CE capillary to provide electrical connection to the CE power supply. pH changes inside the capillary due to electrolysis of the background buffer electrolyte was small and has minimal effects on the CE separation. The peak broadening effects due to the nebulizing gas flow, however, were significant. Resolution decreases quickly when the flow-rate of the carrier gas increases. Sample stacking technique was used to improve the resolution of species of opposite charge, e.g., Cr(VI) vs. Cr(III) ions. Detection limit of Cr based on peak area is approximately 10 ppb for the CE-ICP-AES system.     

ICP-AES法测定方铅矿中多元素的方法研究

采用电感耦合等离子体原子发射光谱法(ICP-AES)进行方铅矿中多元素同时测定.通过对方铅矿样品化学处理试验建立了HCl-NH4Cl-HNO3的溶矿体系.本体系采用基体匹配、背景系数和元素干扰系数校正及元素内标法确定了最佳综合实验测试条件.本实验建立的ICP-AES法同时测定方铅矿中镉、钴、铜、铁、铟、铅、锌7种元素的方法,本方法测量相对误差RE (n=8)为1.50%～7.50%,相对标准偏差RSD (n=8)为1.7%～5.7%.经国家一级标准物质GBW 07269分析验证可以满足方铅矿单矿物样品的分析要求.     

Simultaneous determination of the constituents in Al-Ge-Si alloys by inductively coupled plasma atomic emission spectrometry

An accurate method for determination of the constituents Ge, Si, In and Mg in Al–Ge–Si based compact alloys and foil materials by ICP atomic emission spectrometry is developed. The material samples were dissolved in nitric acid–hydrofluoric acid. Optimum parameters for the simultaneous measurement of the constituent elements are worked out. To compensate the time determined sensitivity fluctuations the analytical signal was corrected by a special procedure of external standardization.     

Simultaneous determination of the constituents in Al-Ge-Si alloys by inductively coupled plasma atomic emission spectrometry

An accurate method for determination of the constituents Ge, Si, In and Mg in Al-Ge-Si based compact alloys and foil materials by ICP atomic emission spectrometry is developed. The material samples were dissolved in nitric acid-hydrofluoric acid. Optimum parameters for the simultaneous measurement of the constituent elements are worked out. To compensate the time determined sensitivity fluctuations the analytical signal was corrected by a special procedure of external standardization.     

Tandem on-line continuous separation and determination of arsenic by inductively coupled plasma atomic emission spectrometry

The principle of tandem on-line continuous separation techniques as an alternative means of introducing samples into plasmas was applied to the development of a sensitive, selective and convenient method for the determination of arsenic by inductively coupled plasma atomic emission spectrometry (ICP-AES). Arsenic is continuously extracted as AsI₃ into xylene from the sample dissolved in 0.1 M potassium iodide solution in 7.2 M hydrochloric acid. The xylene phase (containing the analyte) is continuously mixed on-line with NaBH₄ in dimethylformamide and acetic acid solutions. Arsine is thus continuously generated directly from the organic phase and is separated in a gas—liquid separation device which prevents most of the xylene phase vapour from reaching the ICP. The system was optimized for the continuous extraction of AsI₃, the direct generation of arsine from xylene and the final ICP determination of arsenic. Finally, the tandem on-line continuous separation ICP detection system was applied to the determination of arsenic in real samples (white metal, cast iron, cupro-nickel and orchard leaves standard materials). Very good agreement between the experimental results and the certified values was obtained.     

Development of transient data acquisition system for hyphenated techniques coupled with inductively coupled plasma atomic emission spectrometry

A transient data acquisition system for flow injection analysis (FIA), high performance liquid chromatography (HPLC), and electrothermal vaporization (ETV) combined with ICP-AES multi-element instrumentation was developed and successfully applied to the analysis of different types of samples, including human serum, human hair and tea, for simultaneous multi-element determinations. The accuracy of the method was verified with hair reference material. Good agreement between the experimental results and certified values, and also satisfactory recoveries from standard additions, were achleved.     

Particle sample introduction system for inductively coupled plasma–atomic emission spectrometry

Development and characterization of a new, relatively inexpensive, computer-controlled, particle sample introduction (PSI) system for programmable delivery of small amounts of diluted powdered samples into an inductively coupled plasma (ICP) and measurement by atomic emission spectrometry (AES) is described. The PSI was developed for use with non-hygroscopic particles, in particular those with a particle weight in the ng range (i.e., with a diameter in low μm-range) and for solids that can be converted to a powder (i.e., a collection of particles). In this first report on PSI–ICP–AES, linearity of calibration curves and plasma loading concerns were addressed using three modes of operation. In the first mode, the PSI operated similar to a nebulizer and it delivered to the plasma for a period of 5–10 s a relatively constant amount of particles diluted with graphite. In the second mode, the PSI delivered to the plasma a small “puff” of a diluted sample, thus generating a transient, time-domain signal with duration of about a second. In the third mode, an even smaller “puff” was delivered to the plasma and, using high-speed data acquisition (in the kHz range), time-resolved emission signals from individual, μm-diameter and ng-weight particles were observed. Thus, the PSI can also be thought of as a nano-particle (i.e., ng rather than nm) sample introduction system. Similarly, the high-speed, wide-bandwidth single-channel time-resolved data acquisition mode enabled the determination of particle-size distribution. In addition, a dual-channel (or dual-element) mode enabled homogeneity studies on a per-individual-particle basis. In all modes, linear calibration curves were obtained (provided that plasma loading was avoided). Per-cent relative standard deviation ranged between 3.1% and 4.2% for Ni in certified reference materials but was as high as 50% for heterogeneous soil samples. Tungsten emission signals from refractory tungsten carbide powders were enhanced using mixed gases and by modifying the chemical environment of the ICP using SF₆. Furthermore, when coupled with high-speed data acquisition, PSI brought unique capabilities to ICP–AES for homogeneity studies from individual ng-weight particles and for the determination of particle size distributions. Overall, it was concluded that PSI is an attractive alternative to powder sample introduction systems described in the literature.     

Silicon determination by inductively coupled plasma atomic emission spectrometry after generation of volatile silicon tetrafluoride

A method for the determination of silicon by inductively coupled plasma atomic emission spectrometry (ICP-AES) is described. The procedure is based on a discontinuous generation of volatile silicon tetrafluoride in concentrated sulphuric acid medium after injecting 125 μl of 0.1%, w/v sodium fluoride solution into 100 μl of the sample. The gaseous silicon tetrafluoride is fed directly into the ICP torch by a flow of 250 ml min⁻¹ Ar carrier gas. The calibration curve was linear up to at least 100 μg ml⁻¹ of Si(IV) and the absolute detection limit was 9.8 ng working with a solution volume of 100 μl. The relative standard deviation for six measurements of 10 μg ml⁻¹ of Si(IV) was 2.32%. The method was applied to the determination of silicon in water and iron ores.     

Microwave desolvation for acid sample introduction in inductively coupled plasma atomic emission spectrometry

This study deals with the behaviour of a microwave desolvation system (MWDS) with acid solutions in inductively coupled plasma atomic emission spectrometry. Hydrochloric, nitric, sulphuric and perchloric acids at different concentrations (up to 0.6 mol l⁻¹) have been tested. Sample uptake rate (Q_l) was also varied. The parameters evaluated for each variable were analyte and solvent transport rates and emission intensity. The combination of low acid concentrations (0.05–0.1 mol l⁻¹) and low liquid flows (0.4 ml min⁻¹) leads to the highest analyte transport rate and emission signal and to the lowest solvent transport rate. For Q_l higher than 1.9 ml min⁻¹, the use of an impact bead is advisable. Among the acids tested, sulphuric and perchloric acids give rise to higher emission intensities than hydrochloric acid and nitric acid. Nonetheless, the limits of detection (LODs) obtained with the MWDS are about the same magnitude irrespective of the solution employed. The LODs reached when using the MWDS are similar to those obtained with a desolvation system based on infrared heating of the aerosol.