Determination of 24 elements in four algae reference materials by neutron activation analysis and inductively coupled plasma mass spectrometry

Four algae reference materials, IAEA-391, 392, 393 and IAEA-140, prepared by the International Atomic Energy Agency for intercomparison under different preparation conditions were analyzed for 24 elements. Conventional neutron activation analysis (NAA) was used to determine Al, Ca, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Sb, V and Zn and epithermal NAA using BN and Cd as shielding material for I, Br, As, Ni, Mo and Cd. Inductively coupled plasma mass spectrometry (ICP-MS) as a complementary and comparative method was applied to determine Pb, Sn, Ni, Sr, Rb, As, Co, Cr, Cu, Mn, V, Mo and Zn. Two analytical quality control standard reference materials IAEA-V-10 (hay powder) and IAEA-331 (spinach) were analyzed simultaneously with real samples. The results agree quite well with each other and with the certified values.     

Elemental analysis of special materials by X-ray fluorescence spectrometry

The special materials like phosphor bronze for P, Fe, Ni, Cu, Zn, Sn and Pb; mild steel for P, S, V, Cr, Mn, Co, Ni, Cu, As, Nb, Sb and W; special alloys for Ti and Mo, zircaloy and zirconium oxide for Hf; and zircon ore for Zr have been analyzed by X-ray fluorescence spectrometry (XRFS). The measured values along with certified values, precision and accuracy have been given for all the elements analyzed. Some of these materials have also been analyzed by atomic absorption spectrometry (AAS), neutron activation analysis (NAA) and inductively coupled plasma emission spectrometry (ICP-ES). The analytical data of XRFS are in agreement with the results obtained by AAS-ICP-ES and NAA. In most cases the precision is within ±2% and accuracy is ±4%. The precision and accuracy for S, P, Ni and Hf are poor at low concentrations. Practical low detection limit of about 40 g/g of Hf in zirconium matrix has been achieved. It is established that precise and accurate determination of Ti and Mo in special alloys is possible using XRFS.     

Multi-element analysis of manganese nodules by atomic absorption spectrometry without chemical separation

Five manganese nodules, including the USGS reference nodules A-1 and P-1, were analyzed for Co, Cu, Fe, K, Mg, Mn, Na, Ni and Zn without prior chemical separation by using a simultaneous multi-element atomic absorption spectrometer with an air—cetylene flame. The nodules were prepared in three digestion matrices. One of these solutions was measured using sixteen different combinations of burner height and air/acetylene ratios. Results for A-1 and P-1 are compared to recommended values and results for all nodules are compared to those obtained with an inductively coupled plasma. The elements Co, Cu, Fe, K, Mg, Mn, Na, Ni, and Zn are simultaneously determined with a composite recovery for all elements of 100 ± 7%, independent of the digestion matrices, heights in the flame, or flame stoichiometries examined. Individual recoveries for Co, K, and Ni are considerably poorer in two digests than this composite figure, however. The optimum individual recoveries of 100 ± 5% and imprecisions of 1–4%, except for zinc, are obtained when Co, K, Mn, Na and Ni are determined simultaneously in a concentrated digest, and in another analytical sequence, when Cu, Fe, Mg, Mn and Zn are measured simultaneously after dilution. Determination of manganese is equally accurate in the two sequences; its measurement in both assures internal consistency between the two measurement sequences. This approach improves analytical efficiency over that for conventional atomic absorption methods, while minimizing loss of accuracy or precision for individual elements.     

Elemental analysis of some herbal plants used in the treatment of cardiovascular diseases by NAA and AAS

Elemental analysis of some herbal plants used in the ayurveda for curing of cardiovascular diseases has been performed using the techniques of neutron activation analysis and atomic absorption spectroscopy. The concentration of elements Mn, Na, K and Cl has been estimated by NAA using a²⁵²Cf neutron source and a high purity gemanium detector coupled to a multichannel analyzer, while the elements Ca, Cr, Co, Cu, Fe, Pb, Zn, Ni, Cd and Hg were analysed by AAS using a Perkin Elmer 3100 instrument.     

Comparison of analytical methods: ICP-QMS,ICP-SFMS and FF-ET-AAS for the determination of V,Mn, Ni,Cu, As,Sr, Mo,Cd and Pb in ground natural waters

Three analytical methods, namely, inductively coupled plasma sector field mass spectrometry (ICP-SFMS); inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and filter-furnace electrothermal atomic-absorption spectroscopy (FF-ET-AAS) for the determination of V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb in ground natural water samples were compared and evaluated for their capacity to provide reliable and precise results. Two certified reference materials (SLEW-3 Estuarine Water; SLRS-4 River Water) were analysed to prove that accurate results could be obtained by using all the listed methods with properly optimised parameters. The limit of detection (LOD) for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb provided by the ICP-MS methods ranged from 0.001 to 0.05 µg L^?1. Such LOD proved sufficient for the reliable determination of the listed elements in ground natural waters. However, the LOD of the FF-ET-AAS was approximately two orders of magnitude higher than that of ICP-MS, which made it impossible to quantify V, Mn, Ni, Mo and Pb. The effects of the usage of the collision cell mode in ICP-QMS and of the desolvation system Apex for ICP-SFMS to eliminate oxide ions levels were investigated. For all three analytical methods, the influence of the matrix effect on the results of the determination of the investigated elements using matrix model solution, external calibration and standard addition methods was evaluated. A comparison using a paired Student’s t-test between the results obtained by both ICP-MS methods for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb concentrations in ground natural waters showed that there was no significant difference on a 95% confidence level. The precision of the results for ICP-SFMS, ICP-QMS and FF-ET-AAS varied between ~0.5 and 11; 2.5 and 12.5; 3 and 13.5%, respectively. Moreover, ICP-SFMS equipped with the desolvation system APEX proved a better choice for As, Cu and Mn analysis due to its better LOD (0.008, 0.03 and 0.02 µg L^?1, respectively) and precision (S_r ≤ 5.0; 7.5; 9.0%, respectively) compared to ICP-QMS and FF-ET-AAS.     

Comparative PGAA and NAA results of geological samples and standards

Concentrations of major and trace elements in volcanic rock and soil samples, including geological standard reference materials, were determined by neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA), both using the k ₀-standardization method. The paper highlights the different experimental procedures, such as sample preparation, data collection and spectrum evaluation. In geological samples, PGAA gives precise results for major elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and—as a unique method—for H), for some of the light trace elements as B and Cl, as well as for Sc, S, Cr, Co, Ni, Cd, Nd, Sm and Gd. NAA is sensitive for the rare earth elements, and for many major (Ti, Al, Fe, Mn, Mg, Ca, Na, K) and trace elements (e.g.: Sc, V, Cr, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Zr, As, Sb, Ce, Ba, Hf, Ta, W). For most major elements the results obtained by the two methods show good agreement. The comparison of the results obtained for trace elements is not always possible, since PGAA is less sensitive and concentrations are often below its detection limits. Nevertheless, the complementarity of NAA and PGAA allows nearly panoramic analysis of geological materials.     

煤中痕量元素在循环流化床锅炉中的迁移行为与富集特性

对天津市某电厂循环流化床(CFB)锅炉燃用的原煤及燃烧产物底灰、飞灰、细飞灰(≤50 μm)进行痕量元素含量的测定,分析了Be、Zn、Hg、V、Cr、Mn、Co、Ni、Cu、As、Se、Cd、Pb 13种痕量元素在燃烧过程中的迁移行为,揭示了痕量元素在CFB锅炉中的分配、富集特性。结果表明,CFB锅炉中,较低的炉温对于痕量元素的迁移富集产生了较大的影响。由相对富集系数得知,Be、V、Co、Se在底灰中耗散,在飞灰中富集,Zn、Mn倾向于在底灰中富集,元素Cd、Pb、Ni、Cu挥发性较强,在底灰和飞灰中均是耗散。As受钙氧化物影响,挥发性表现并不明显。Hg在底灰和飞灰中相对富集系数均很低,表明Hg在整个燃烧过程中以气态形式排放;Hg、As、Se、V、Cr、Mn、Co、Ni、Cu、Zn、Pb均有向小颗粒物中富集的趋势。根据相对富集系数以及研究的13种元素在低温CFB锅炉中的迁移行为,将这些元素分为三类:A类(E_R<0.1),主要是以气态形式排放元素Hg;B类(0.1R≤0.85),较易挥发元素As、Be、Ni、Cu、Se、Cd、Pb、Co、V;C类(E_R>0.85),主要残留在固体产物中元素Zn、Mn、Cr。     

Development of multi-elemental method for quality control of parenteral component solutions using ICP-MS

An inductively coupled plasma mass spectrometry (ICP-MS) method for elemental impurities determination in components used for parenteral nutrition solutions is proposed. Solutions of amino acids (10% m/v), glucose (50% m/v) and lipids (20% m/v) were analyzed. Arsenic, Cd, Cu, Pb and Mo were determined by ICP-MS operated at standard mode, whilst pneumatic nebulization was used for introducing the sample solution into the ICP. Mercury was determined using cold vapor generation (CVG) coupled to ICP-MS. Chromium, Mn, Ni and V were determined by means of dynamic reaction cell-inductively coupled plasma mass spectrometry (DRC-ICP-MS), while ammonia was used as reaction gas. The operational conditions of each technique were optimized in order to achieve better sensitivity, precision and accuracy. The influence of the sample matrix, mainly carbon, on all investigated elements was evaluated. The use of DRC was effective to reduce interferences on Cr, Mn, Ni and V determination. The other investigated elements (As, Cd, Cu, Pb, Mo and Hg) were determined directly in the samples, which were properly diluted. Results obtained were in good agreement (between 96 and 103%) with certified values (certified reference materials of water were analyzed), at the same time as the relative standard deviation was lower than 5%. Sample throughput was relatively high (up to 30 samples of components used for parenteral nutrition solution could be analyzed per hour). In this way, the proposed method can be recommended for routine analysis.     

Photon activation analysis of trace metals in biological materials via collection of metal tropolone-5-sulfonate complexes onto anion-exchange resin

Tropolone-5-sulfonic acid was used to separate and collect trace elements as their complexes onto an anion-exchange resin in photon-activation of biological materials. Retention behaviour of the anionic complexes of Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb on Dowex 1-X8 resin was examined with respect to pH, amount of resin, concentration of the ligand, and coexisting salt anions, using radioisotope tracers. Under optimum conditions, Cr, Mn, Co, Ni, Zn and Pb were collected from the irradiated samples of NBS-SRM Orchard Leaves, NBS-SRM Spinach, green tea and black tea on the marcket. The analytical results agreed with certified values and the reproducibility was good.     

主成分分析用于浙贝母中无机元素含量的研究

采用原子吸收光谱（AAS）法测定了10个浙贝母样品中12种无机元素的含量,建立浙贝母无机元素指纹图谱,并用SPSS13．0方差分析和主成分分析对浙贝母中的微量元素进行了分析。结果表明,浙贝母的特征无机元素是Cd,Cu,Pb,Mg,Cr,Fe,Zn。可见主成分分析法是浙贝母无机元素分析的有效方法。