Survey and evaluation of available biological reference materials for trace element analysis

Summary A database recently prepared by IAEA contains information on 60 internationally available biological reference materials (BRMs) from 9 producers. The data recorded for each material include: name, code No., cost, list of elements, and minimum weight of material recommended for analysis. For each element the concentration and its confidence interval (CI) are recorded, as well as an indication of whether the concentration value is certified or noncertified (e.g. an information value).Large differences among producers are observed in respect of how the concentration values and their CIs are defined, and how other relevant information is reported in the certificates of analysis. International recommendations on how this should be done generally do not seem to be followed.For several elements of biomedical interest there is a serious lack of BRMs namely: Al, F, I, Mo, Si, Sn and V. In addition, the CIs for the following elements are generally excessively large: Al, As, Cd, Cr, Hg, Mo, Ni, Se and V.     

微波消解ICP-MS快速测定生物样品中的多种元素

建立了微波辅助HNO3消解样品,ICP-MS快速测定生物样品中Ti、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ge、As、Se、Sr、Mo、Ag、Cd、I、Ba、Hg、Tl、Pb、Bi共21种微量及痕量元素。通过在线加入内标来校正基体效应和信号漂移对测量所造成的影响。各元素线性相关系数在0.9990以上,RSD小于6.0%。用本方法对国家标准样品GBW07601a(头发),GBW10010(大米),GBW10016(茶叶),GBW10023(紫菜)进行分析,结果满意。方法能满足生物样品痕量分析的要求。     

Trace element analysis of biological materials by thermal and epithermal neutron activation analysis

A scheme for instrumental neutron activation analysis of biological materials is proposed. The scheme is based on a combination of thermal and epithermal activation. The accuracy is evaluated by analyzing 4 standard reference materials. Results from the analysis of human blood serum and plasma are given.     

Trace element analysis and microanalysis of silicate and carbonate rocks by flameless atomic absorption spectrophotometry

Summary Flameless atomic absorption spectrophotometric methods for the microanalysis and trace element analysis of rocks are described. The microanalysis of the elements Al, Fe, Mn and Ti so far determined can be carried out in the diluted solution of the digested samples (2.5 mg substance/250 ml to 5 mg/100 ml) without additional separation. In the case of trace element analysis the elements may be determined either directly in the solution (Sr, Pb) or after separation. Separation can be carried out by extraction from the solution (Tl) or by the volatilization technique with the solid substance heated to 1000–1200°C (Tl, Pb, Cd, Bi). For Hg the method of electrolytical separation together with the volatilization technique is suitable. The methods were tested with rock standards for precision and accuracy.

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Spuren- und Mikroanalyse von Silicat- und Carbonatgesteinen durch flammenlose Atomabsorptions-Spektralphotometrie

Zusammenfassung Verfahren zur Mikro- und Spurenanalyse von Gesteinen mit Hilfe der flammenlosen Atomabsorptions-Spektralphotometrie werden beschrieben. Bei der Mikroanalyse können ohne zusätzliche Trennverfahren die bisher untersuchten Elemente Al, Fe, Mn und Ti direkt aus den verdünnten Aufschlußlösungen (2,5mg Probe/ 250 ml bis 5 mg/100 ml) bestimmt werden. Bei der Spurenanalyse erfolgt die Bestimmung entweder direkt aus der Aufschlußlösung (Sr, Pb) oder nach Abtrennung des Elementes. Die Abtrennung kann mittels Extraktion aus der Aufschlußlösung (Tl) oder auch durch Verdampfung aus der Festsubstanz bei 1000–1200°C (Tl, Pb, Cd, Bi) erfolgen. Für Hg eignet sich ein elektrolytisches Trennverfahren in Verbindung mit der Verdampfungsanalyse. Die Verfahren wurden mit Gesteinsreferenzproben auf ihre Reproduzierbarkeit und Genauigkeit geprüft.

We thank Prof. Dr. K. H. Wedepohl for his continued interest in our work and we are grateful to him for his generous support. We are much obliged to Prof. Dr. A. G. Herrmann for his valuable advice and encouragement in technical matters. Financial assistance from the DFG is gratefully acknowledged.     

A set of four soil reference materials with certified values of total element contents and their extractable fractions

A set of certified reference materials of four natural soils denoted as CRM 7001-4 was prepared. They consist of light sandy soils with normal and elevated, silty clay loam with normal, and loam with elevated element levels. Certified and/or information values were established for the total contents of the elements As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, Zn, and their fractions, extractable with aqua regia, and boiling and cold 2 mol L^–1 nitric acid, from results of a 28 laboratory intercomparison using various methods of atomic absorption spectrometry, optical emission spectrometry, mass spectrometry, electrochemical methods, spectrophotometry, instrumental neutron activation analysis, and X-ray fluorescence.     

Scheme and studies of reference materials for volumetric analysis in Japan

This paper describes the history and scheme of reference materials and standard solutions for titrimetry in Japan. Titrimetry is one of the most fundamental and precise methods for determination of a constituent, based on the effective purity of reference materials in stoichiometric analysis. It has wide-ranging applications based on titrimetric reactions such as neutralization, redox, chelatometric, and precipitation titration processes, which are used in various analytical fields all over the world. Japanese Industrial Standards (JIS) have played an important role in establishing a stable supply of reference materials for titrimetry since the 1950s. There are several reports of preparations and their determination, including coulometric studies, in order to establish highly reliable reference materials. This paper briefly reviews the schemes and studies of standardization through the provision of reference materials and standard solutions based on JIS, and several applications in other standards. Presented at Berm-11, October 2007, Tsukuba, Japan.     

Use of INAA in the preparation of a set of soil reference materials with certified values of total element contents

A set of certified Reference Materials was prepared consisting of four natural agricultural soils with normal (n) and elevated (e) levels of element contents: CRM 7001 Light Sandy Soil (n), CRM 7002 Light Sandy Soil (e), CRM 7003 Silty Clay Loam (n), and CRM 7004 Loam (e). In these materials, certified and/or information values of the total contents of the elements As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V and Zn, and their fractions extractable by aqua regia, boiling and cold 2M nitric acid were derived from an interlaboratory comparison in which 28 laboratories participated. Highly precise and accurate procedures of instrumental neutron activation analysis (INAA) were employed for homogeneity testing and also for certification of the total element contents. For comparation purposes, NIST SRM-2704 Buffalo River Sediment was analyzed by INAA, as well. The INAA results obtained compared very well with the certified and/or information values for four soil CRMs and also with NIST values for SRM-2704. From this agreement, a very high reliability of the new soil CRMs can be inferred.     

Certified sediment reference materials for trace element analysis from the National Metrology Institute of Japan (NMIJ)

Two types of sediment reference material (NMIJ 7302-a and 7303-a) for trace elements analysis have been prepared and certified by the National Metrology Institute of Japan in the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). The original materials were collected from a bay near industrial activity in Kyushu (NMIJ CRM 7302-a; marine sediment) and from Lake Biwa (NMIJ CRM 7303-a; lake sediment). The sediment materials were air-dried, sieved, homogenized, packaged in 1000 glass bottles (60 g each), and radiation sterilized. Certification of these CRM for trace elements was conducted by NMIJ, where each element was determined by at least two independent analytical techniques. Isotope-dilution inductively coupled plasma mass spectrometry (ICP–MS) was applied for certification of all the elements except mono-nuclide elements such as As and Co. Other techniques such as ICP–MS with quadrupole mass spectrometry and sector-field mass spectrometry, inductively coupled plasma atomic emission spectrometry (ICP–AES), and atomic absorption spectrometry (AAS), were also used. Certified values have been provided for 14 elements (Sb, As, Cd, Cr, Co, Cu, Pb, Hg, Mo, Ni, Se, Ag, Sn, and Zn) in both CRM.     

Trace element content of phosphorite reference materials (BCR-RM-032, PRH and IAEA-434)

Analysis of geological materials requires the use of matrix specific reference materials (RMs). Phosphate rocks (PR), the basic ingredient of phosphate fertilizers, are very important in agriculture. A project was undertaken to study the PRs of the Hazara Deposits of Pakistan. Due to the unavailability of phosphate rock reference materials (PR-RMs) with a large number of certified elements, validation of the results was problematic when carrying out elemental analysis of PR samples and their derived products. Therefore a parallel study was performed to determine the composition of three phosphate based RMs; BCR-RM-032 (Natural Moroccan Phosphorite), IAEA-434 (Phosphogypsum) and PRH (a local PR-RM from the Hazara Deposits of Pakistan). Instrumental Neutron Activation Analysis was used for this purpose and more than 30 elements including rare earth elements were determined in the three PR samples.     

Geological reference materials for standardization and quality assurance of instrumental neutron activation analysis

Results are presented from the INAA of 34 elements in NIST and USGS geological reference materials that were analysed relative to multielemental SRM-1633a Coal Flyash standards. The data compare favorably with works reported by other investigators. The application of historical control charts for continuous monitoring of quality assurance and detection of systematic errors is demonstrated.     

Trace element abundances in stone artifacts and related materials from Japan by neutron activation analysis. An approach to archaeological provenience studies

Instrumental neutron activation analysis was carried out for trace elements in green tuff cylindrical beads (KUDATAMA) and obsidians unearthed from the sites with special reference to their archaeological provenience studies. An approach based on the characteristic index elements, the correlation diagrams of some of the elements interested, and the abundance patterns of some of rare earth elements is valid for clarifying the different source regions.     

Trace element analysis of archaeological materials and the use of pattern recognition methods to establish identity

Trace elements were determined in South West African potsherds by instrumental NAA and by PIXE. The elements for which the relative spread of concentrations were greatest were selected as indicators. From these the methods of the Minimal Spanning Tree and of Nonlinear Mapping were used to classify about 60 specimens. Groups were tested by concentration, sum of concentration and normalized concentration indices. Similar groupings were obtained irrespective of which analytical data or mathematical techniques was used.     

Trace determination of nickel (and cobalt) in biological reference materials by radiochemical neutron activation analysis

Summary Very few biological reference materials are certified for nickel below 1 mg · kg^–1. Neutron activation analysis was only rarely considered as a possible approach; reported sensitivities were usually not very good, unless preconcentration was applied.In the present work, the relatively high fast neutron flux of our TRIGA reactor was used to induce the ⁵⁸Ni(n, p)⁵⁸Co reaction, and ⁵⁸Co (E =811 keV) was radiochemically separated from other radionuclides by classical anion-exchange chromatography in hydrochloric acid. ⁵⁷Co was added to the irradiated sample before decomposition as a radioisotopic yield monitor. By concentrating the final sample fraction and measurement in a well-type HP Ge detector, Ni concentrations down to the 10-g · kg^–1 level could be determined for samples irradiated for 1 day. ⁶⁰Co, produced by neutron capture on ⁵⁹Co, is also coseparated and quantified from the gamma spectrum, so that both elements Ni and Co are determined. Results are reported for a series of NBS and other biological reference materials in the concentration range 10 g-10 mg · kg^–1. Possibilities for further increases in sensitivity are discussed.

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Spurenbestimmung von Nickel (und Cobalt) in biologischen Referenzmaterialien durch radiochemische Neutronenaktivierungsanalyse

     

Atomic spectrometry methods for wine analysis: a critical evaluation and discussion of recent applications

The analysis of wine is of great importance since wine components strongly determine its stability, organoleptic or nutrition characteristics. In addition, wine analysis is also important to prevent fraud and to assess toxicological issues. Among the different analytical techniques described in the literature, atomic spectrometry has been traditionally employed for elemental wine analysis due to its simplicity and good analytical figures of merit. The scope of this review is to summarize the main advantages and drawbacks of various atomic spectrometry techniques for elemental wine analysis. Special attention is paid to interferences (i.e. matrix effects) affecting the analysis as well as the strategies available to mitigate them. Finally, latest studies about wine speciation are briefly discussed.     

Trace element analysis of placentas of alcoholics and controls with external beam PIXE

External beam PIXE analysis with a protonbeam of 2.4 MeV was used to study trace element concentrations in human placentas. The aim was to check the suitability of PIXE analysis regarding soft tissue samples. Sample preparation was kept as simple as possible to avoid contamination or losses due to volatilization. The element of interest /Fe, Cu, Zn, Se, Br, Rb, and Sr/ were easily detected. A comparison was made with placental samples of alcoholics and abstinent controls to determine whether trace element concentrations in the placenta play a role in the pathogenesis of fetal alcohol syndrome.     

Chemical analysis of high-pressure metamorphic rocks by PGNAA: Comparison with results from XRF and solution ICP-MS

Summary High-pressure metamorphic rocks showing a large range of chemical compositions were analyzed by PGNAA, XRF and solution ICP-MS for major components and a variety of trace elements. The large data set allowed a comparison of results from PGNAA to the established methods and revealed good agreement for most major elements and for Sc and Gd. For V, Cr, Co and Ni, PGNAA data are satisfactory only at high concentration levels. B, Cl and H were analyzed by PGNAA with very good precision, even at low concentrations.