Inductively coupled plasma atomic emission spectrometric determination of 27 trace elements in table salts after coprecipitation with indium phosphate

The coprecipitation method using indium phosphate as a new coprecipitant has been developed for the separation of trace elements in table salts prior to their determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). Indium phosphate could quantitatively coprecipitate 27 trace elements, namely, Be, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, in a table salt solution at pH 10. The rapid coprecipitation technique, in which complete recovery of the precipitate was not required in the precipitate-separation process, was completely applicable, and, therefore, the operation for the coprecipitation was quite simple. The coprecipitated elements could be determined accurately and precisely by ICP-AES using indium as an internal standard element after dissolution of the precipitate with 5 mL of 1 mol L⁻¹ nitric acid. The detection limits (three times the standard deviation of the blank values, n = 10) ranged from 0.001 μg (Lu) to 0.11 μg (Zn) in 300 mL of a 10% (w/v) table salt solution. The method proposed here could be applied to the analyses of commercially available table salts.     

无滤共沉淀富集-等离子体原子发射光谱法测定痕量稀土元素

以编结反应器 (KR)作为反应场所,用NH3～NH4NO3缓冲溶液在线沉淀、富集,电感耦合等离子体原子发射光谱法(ICP-AES)检测稀土元素,系统地研究了稀土元素在线沉淀及溶解的最佳条件.实验结果表明:在80 ℃时,稀土离子与pH 9.0的NH3～NH4NO3缓冲溶液在线混合后经2 m KR富集120 s,用1 mol/L HNO3以1.0 mL/min流速洗脱时富集效果最好,富集倍数可达52～76倍,进样频率为10/h.同时考察了共存离子的干扰及其消除方法.方法的稀土元素的检出限为0.07～1.23 μg/L,精密度RSD在1.7%～4.3%之间(n=6),线性范围2～10 μg/L.应用于标准样品中痕量稀土元素的测定,其测定值与标准值吻合.     

电感耦合等离子体-发射光谱分析中硫酸基体效应及抑制

研究了电感耦合等离子体-发射光谱分析中的硫酸基体效应及克服干扰的有效方法。对2%~20%范围内4种不同体积分数H2SO4溶液中30种元素的基体效应进行了观察,发现H2SO4对各元素的谱线发射强度均存在明显的抑制作用。实验证实体积分数5%乙酸可有效抑制H2SO4的基体效应,并建立了H2SO4溶液中痕量元素的电感耦合等离子体-发射光谱分析法。     

电感耦合等离子体原子发射光谱法（ICP-AES）测定RoHS指令聚合物中的铅和镉

本文引入微波技术消解聚合物塑料样品,使用电感耦合等离子体原子发射光谱仪（ICP-AES）测定聚合物中的铅（Pb）和镉（Cd）含量,并建立了优化的样品消解程序和测定方法,得到满意的测定结果。[摘要应包括目的、方法、结果、结论,请修改,同时修改英文]该方法具有效率高、污染小的优点。检测结果具有良好的精密度。     

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.     

Inductively coupled plasma optical emission spectrometric determination of trace element in PM10 airborne particulate matter collected in an industrial area of Argentina

Trace metals of relevance from the environmental and toxicological point of view were quantified in the city of Campana, Buenos Aires, Argentina. The collection of particulate matter was performed on ash-free fiber glass filters using high-volume samplers with a PM₁₀ sampling head, during a 3-month period in 2002. An acid leaching of elements deposited on the filters was adopted paying special attention to the recovery of volatile elements. Analysis was performed by inductively coupled plasma optical emission spectrometry (ICP OES) to ascertain the concentrations of 12 key elements, namely, Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn. The validation of the procedure was performed by the analysis of the standard reference material NIST 1648, urban particulate matter, and good agreement between concentrations found and the reported certified values was achieved. Blank filters were spiked with the analytes investigated and the recoveries varied between 83% and 92%. Metal concentrations spanned the range 0.03 ng m⁻³ (equivalent to 0.42 μg g⁻¹) for Cd to 1.9 μg m⁻³ (equivalent to 29.7 mg g⁻¹) for Fe. The results obtained show that the pollutants of special environmental and health concern are As and Pb. Mean As concentration was higher than the guideline value associated with an excess cancer risk of 1:10⁻⁶, reported by the World Health Organization (WHO). Lead is the only element that showed higher concentrations than those recently measured in the large and heavily trafficked metropolitan area of Buenos Aires. Cadmium>Pb>As>Zn>Cu are the elements more enriched in airborne PM₁₀.     

ICP-AES 法测定硅铁中痕量元素

采用电感耦合等离子原子发射光谱法测定硅铁中的痕量元素,研究了 Fe 基体对被测元素的影响,并选择了最佳工作条件.被测元素的检测限为 0 .60～76.2 ng/mL,样品加标回收率为 92%～108%,RSD(n=8)<3%.     

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.     

Application of Metalfix Chelamine prior to the determination of noble metals by the inductively coupled plasma atomic emission spectrometry

Metalfix Chelamine chelating resins of two different bead sizes (150-300 and 40-80 μm) were examined and compared regarding their application for sorption of Au, Ir, Pd, Pt, Rh and Ru ions from medium of HCl, HNO₃ and mixtures of HCl and HNO₃. The quantitative enrichment of Au, Ir, Pd and Pt was established for the resin of 150-300 μm particle size and for solutions acidified with HCl and HNO₃ (3:1) up to the concentration of 0.50 mol l⁻¹. In the case of Rh and Ru, the uptake of these metals by the resin was lower than 50%. For the elution, solutions of different reagents, i.e. HCl, HNO₃, KCN, KI, KSCN and (NH₂)₂CS, were studied with respect to the complete release of the analytes retained by the resin. In addition, influence of various base metals, i.e. Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, on the retention of the noble metals was investigated. Under the selected conditions for the retention and elution of Au, Ir, Pd and Pt, the analytical performance of the proposed pre-concentration procedure was evaluated and it was applied to the determination of these noble metals in anodic sludge sample.     

Matrix effects in the analysis of biological matrices by axial view inductively coupled plasma optical emission spectrometry

We are reporting observations of positive and negative variations of emission line intensities during the determination of boron and titanium in biological matrices by axial view inductively coupled plasma optical emission spectrometry with segmented charge-coupled device detection. The study included the testing of several elements (yttrium, palladium and platinum) and analytical wavelengths for internal standardization, aiming to compensate for variations in signal recovery due to matrix interferences. Human albumin was chosen as principal matrix component to assess the effect of variable chemical and instrumental operating conditions on boron response. A parametric study was performed by considering the application of two different nebulizer–aerosol chamber systems, the effect of plasma operating conditions on analyte and internal standard signals and the influence of common blood plasma electrolytes, added as salts of alkaline or alkaline earth elements. The pneumatic injection systems tested were a standard cross-flow nebulizer with a Scott type spray chamber and a concentric Meinhard type device coupled to a glass cyclonic spray chamber. The change from standard (i.e. medium RF power and relatively high aerosol carrier gas flow rate) to robust (i.e. higher RF power and lower carrier gas flow rate) conditions contributed to large, non-correlated variations in boron intensities and in some of the analyte/internal standard ratios. Significant memory effects were observed for injection of boron solutions prepared with boric acid and containing small amounts of acid, but those effects were negligible when the boron carrier compound was boronophenylalanyne. The injection of titanium solutions did not produce analyte carry-over effects. When internal standards were employed, a less effective signal compensation was consistently observed for boron at higher albumin concentrations when the difference in energies of the lines was between 4.5 and 6 eV. This effect was enhanced for some line pairs when robust conditions are employed. Differences in the response between nebulizers were minor, with a slight advantage in sensitivity for the cross-flow/Scott system. Yttrium was found to be useful for signal compensation in the determination of boron and titanium in blood and human plasma provided that the equivalent concentration of albumin in the nebulized sample dilutions was kept below 0.2% w/v. Simultaneous measurement of a reference strontium line was found to be useful as an additional verification of the response of yttrium as internal standard.     

Investigations on the use of pneumatic cross-flow nebulizers with dual solution loading including the correction of matrix effects in elemental determinations by inductively coupled plasma optical emission spectrometry

The use of a so-called trihedral and a T-shaped cross-flow pneumatic nebulizer with dual solution loading for inductively coupled plasma optical emission spectrometry has been studied. By these devices analyte clouds from two solutions can be mixed during the aerosol generation step. For both nebulizers the correction of matrix effects using internal standardization and standard addition calibration in an on-line way was investigated and compared to elemental determinations using a conventional cross-flow nebulizer and calibration with synthetic standard solutions without matrix matching. A significant improvement of accuracy, both for calibration with internal standardization and standard addition, was obtained in the case of four synthetic solutions containing each 40 mmol L^− 1 Na, K, Rb and Ba as matrix elements and 300 μg L^− 1 Cd, Co, Cr, Cu, Fe, Mn, Ni and Pb as analytes. Calibration by standard addition in the case of dual solution loading has been shown to be very useful in the determination of elements at minor and trace levels in steel and alumina reference materials. The results of analysis for minor concentrations of Cr, Cu and Ni in steel as well as for Ca, Fe, Ga, Li, Mg, Mn, Na, Si and Zn in alumina powder certified reference materials subsequent to sample dissolution were found to be in good agreement with the certificates. Limits of detection were found to be only slightly above those for a conventional cross-flow nebulizer and a precision better than 3% was realized with both novel nebulizers.     

微波消解-电感耦合等离子体质谱同时测定普里兹湾沉积物中微量元素

以HNO3-H2O2为消解体系,采用微波对沉积物进行消解,建立了普里兹湾沉积物中微量元素的电感耦合等离子体质谱(ICP-MS)测定方法。从样品分析数据可以看出:8个站位10种元素总量变化范围为493.41～1481.02μg/g,总量最大值是最小值的3.00倍。元素Ba、Mn在总量中占了很大比例,V次之,而As、Mo、Ag、Cd的含量很少。大部分元素检出限可达ng/L,仅Co、Mo 2种元素的检出限稍高;各元素线性良好,相关系数r2≥0.9997。方法的RSD<5.0%,适用于普里兹湾沉积物中微量元素的定量分析。     

Preconcentration and atomic spectrometric determination of rare earth elements (REEs) in natural water samples by inductively coupled plasma atomic emission spectrometry

The usage of a variety of sorbents has been shown as promising matrix removal/preconcentration strategies for the determination of rare earth elements (REEs) in various natural water samples by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sorption efficiency of various zeolites (clinoptilolite, mordenite, zeolite Y, zeolite Beta), ion-exchangers (Amberlite CG-120, Amberlite IR-120, Rexyn 101, Dowex 50W X18) and chelating resins (Muromac, Chelex 100, Amberlite IRC-718) towards REEs was investigated in terms of solution pH, shaking time and sorbent amount. The results have shown that most of the materials can take up REEs at a wide pH range. The experiments were continued with clinoptilolite, zeolite Y and Chelex 100 and it was demonstrated that all three materials displayed very fast kinetics for REE sorption (higher than 96% in 1 min). Desorption from the sorbents was realized with 2.0 M HNO₃ for clinoptilolite and 0.1 M HNO₃ for zeolite Y and Chelex 100. Only the lower concentration range (0.01-2.0 mg l⁻¹) of matrix-matched standards were used in quantitation although the calibration graphs were linear at least up to 10.0 mg l⁻¹ for all REEs studied. The limit of detection (3 s) without preconcentration was 0.1, 1.0, and 0.2 μg l⁻¹ for Eu, La, and Yb, respectively. The validity of the method with the selected sorbents was checked through spike recovery experiments.     

Accurate determination of trace amounts of phosphorus in geological samples by inductively coupled plasma atomic emission spectrometry with ion-exchange separation

In order to determine trace amounts of phosphorus in geological and cosmochemical rock samples, simple as well as reliable analytical schemes using an ICP-AES instrument were investigated. A (conventional) ICP-AES procedure could determine phosphorus contents at the level of several 100 μg g⁻¹ with a reasonable reproducibility (<10% for 200 μg g⁻¹; 1σ). An ICP-AES procedure coupled with matrix-separation using cation and anion exchange resins could lower the quantification level down to 1 μg g⁻¹ or even lower under the present experimental conditions. The matrix-separation ICP-AES procedure developed in this study was applied to twenty-one geological reference samples issued by Geological Survey of Japan. Obtained values vary from 1250 μg g⁻¹ for JB-3 (basalt) to 2.07 μg g⁻¹ for JCt-1 (carbonate). Matrix-separation ICP-AES yielded reasonable reproducibility (less than 8.3%; 1σ) of three replicate analyses for all the samples analyzed. In comparison of our data with certificate values as well as literature or reported values, there appear to be an apparent (and large) discrepancy between our values and certificate/reported values regardless of phosphorus contents. Based on the reproducibility of our data and the analytical capability of the matrix-separation ICP-AES procedure developed in this study (in terms of quantification limit, recovery, selectivity of an analyte through pre-concentration process, etc.), it is concluded that certified values for several reference standard rocks should be reevaluated and revised accordingly. It may be further pointed that some phosphorus data reported in literatures should be critically evaluated when they are to be referred in later publications.     

酸溶-电感耦合等离子体发射光谱法测定白云石和菱镁石中主次元素

利用电感耦合等离子体原子发射光谱仪( ICP-AES)建立白云石和菱镁石中铝、钙、铁、镁、锰、磷、硅、锶的测定方法。研究了酸体系、温度及消解方式对试样消解的影响,结果表明,使用5 mL盐酸和硝酸混合酸(1：3)-0.75 mL氢氟酸-5 mL水以密闭消解的方式在150 ℃下消解白云石和菱镁石30min,并以2mL饱和硼酸络合多余的氢氟酸,可以得到澄清消解液。通过白云石和菱镁石中铝、钙、铁、镁、锰、磷、硅、锶的谱线干扰情况,选择Al 308.215 nm、Ca 318.127 nm、Fe 261.187 nm、Mg 277.983 nm、Mn 257.61 nm、P 213.618 nm、Si 251.611 nm、Sr 421.552 nm作为分析线,各元素的校准曲线在线性范围内线性关系良好,相关系数均不小于0.999。按照实验方法测定白云石和菱镁石标准物质,各元素结果的相对标准偏差 (RSD, n=6)为0.89~3.19%,测定值与认定值无显著性差异。本方法有效解决了白云石和菱镁石快速有效溶解及准确测定问题。     

Determination of trace elements in human serum by inductively coupled plasma atomic emission spectrometry with flow injection

An analytical method for the simultaneous determination of some trace elements (Au, Fe, Mg, Li, Sr, Zn) in human serum by inductively coupled plasma atomic emission spectrometry (ICP-AES) with flow injection is described. Physical interference caused by the change of sample viscosity is discussed. When 100 μl of serum was injected, the relevant recoveries of > 99% for Li, > 98% for Cu and Mg, > 95% for Fe were obtained for an NIST SRM with R.S.D. > 1.3% using optimized flow injection parameters. The prepared lyophilized control serum for routine analysis in clinical laboratories was analyzed and verified for the validity of the technique employed in this experiment using NIST SRM 909 as a primary reference material.     

Matrix effects in inductively coupled plasma mass spectrometry: a review

Fundamental research on non-spectroscopic interferences, also known as matrix effects, in inductively coupled plasma (ICP) mass spectrometry with sample introduction using nebulization is critically and exclusively examined in this review, starting with fundamental processes that may be a source of matrix effects during sample introduction, ion generation in the ICP, ion extraction through the interface, and ion transport through the ion optics to the detector. Various methods for attenuating matrix effects are then reviewed and illustrated with some examples. Instead of exhaustively reviewing the literature, representative references are used to comprehensively describe the main issues, several of which are also common to ICP optical emission spectrometry.     

电感耦合等离子体原子发射光谱法同时测定高强度玻璃纤维粉体中9种金属元素

建立电感耦合等离子体原子发射光谱法测定高强度玻璃纤维粉体中铝、镁、钙、铁、钛、锂、铈、钠、钾9种金属元素含量的方法。采用氢氟酸、高氯酸和盐酸分两段溶解样品,分别在选定的各元素分析谱线下,采用电感耦合等离子体原子发射光谱仪测定各元素含量。9种金属元素在各自的质量浓度范围内与光谱强度成良好的线性关系,相关系数均大于0.999,检出限为8.0~17.4 μg/g。测定结果的相对标准偏差小于1.8%(n=6),加标回收率为97.6%~103.7%。该方法准确,简便,快速,适用于高强度玻璃纤维中多金属元素的同时测定。     

Application of wavelet transform to background correction in inductively coupled plasma atomic emission spectrometry

A background correction method based on wavelet transform was devised and applied to inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed approach separated background from analyte signal according to their different frequencies. Compared with the analyte signal, the background has a low frequency. By removal of the components attributed to the signal, the background over the spectral window of the analyte line can be fitted through wavelet reconstruction. The results showed that the wavelet transform technique could handle all kinds of background and low signal-to-background ratio spectra, and required no prior knowledge about the sample composition, no selection of suitable background correction points, and no mathematical assumption of the background distribution. This technique performed as well as the conventional three-point background correction method for linear backgrounds, and provided better results than the latter for curved backgrounds. The proposed procedure was illustrated, by processing real spectra, to be an effective and practical tool for background correction in ICP-AES.     

Determination of trace amounts of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment by inductively coupled plasma atomic emission spectrometry after iron matrix removal with extractant-contained resin

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was applied to the determination of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment. Samples were dissolved with hydrochloric acid and hydrogen peroxide. The digest was passed through a column, which was packed with a polymer resin containing a neutral organophosphorus extractant, tri-n-butylphosphate. Iron was sorbed selectively on the resin and the analytes of interest passed through the column, allowing the effective separation of them from the iron matrix. Conditions of separation were optimized. The detection limits (3σ) in solution were 10, 40, 7 and 5 μg L⁻¹, and in pigment were 0.2, 0.8, 0.14 and 0.1 mg kg⁻¹ for lead, arsenic, cobalt and nickel, respectively. The recoveries ranged from 95% to 107% when sample digests were spiked with 5 μg of the analytes of interest, and relative standard deviations (n = 6) were 1.5-17.6% for the determination of the spiked samples. The method was successfully applied to the determination of trace amounts of these elements in high-purity iron oxide pigment samples.