Implementation of a ”data filter” for the UK National Marine Monitoring Programme

The implementation of a strategy for the assessment of the validity of environmental monitoring data – a ”data filter”– is described. The approach was developed through the UK National Marine AQC Scheme for application to data collected during the UK National Marine Monitoring Programme. Data reported for the year 1999, by nine laboratories, for 74 determinand-matrix combinations were assessed on the basis of the completeness of their supporting quality assurance and quality control information. The approach to the establishment of criteria of acceptability for quality information is described. Received: 28 August 2001 Accepted: 29 November 2001     

Extended Hückel calculations on n-v addition compounds

Extended Hückel calculations are found to satisfactorily account for the various properties of the n-v addition compounds.The authors are thankful to the staff of the I.I.T. Kanpur Computer Centre for assistance with the IBM 7044 computer and to the U.S. National Bureau of Standards for a research grant under their Special International Programme.     

Chemical sensors based on π-conjugated organic molecules and gold nanoparticles

Scientists have developed techniques for synthesizing and characterizing many new materials including conjugated small molecules, polymers and gold particles protected by conjugated organic chromophores for testing specific sensing properties in the past decade. Still, the design and synthesis or supermolecular systems fabrication of novel materials with controlled sensing properties is a significant and ongoing challenge within nanoscience and nanotechnology. Recently, our group has successfully constructed a series of chemosensors using small organic molecules, conjugated polymers and gold nanoparticles for real-time detection of specific analytes. The chemosensors show high selectivity and sensitivity in the detection of cations and biologic analytes and thus are potentially promising for applications in sensing assay system. In this review, recent sutdies on the design, synthesis and photo-physical properties of novel materials and construct of chemosensors are summarized with an emphasis on the development in our groups in recent years. Supported by the National Natural Science Foundation of China (Grant Nos. 20531060, 20721061 & 20873155), and the National Basic Research 973 Programme of China (Grant No. 2007CB936401)     

Some development for radioanalytical separations

Some recent developments in separation techniques with applications to nuclear analytical methods are summarised. The projects discussed are part of an International Atomic Energy Agency Coordinated Research Programme and cover both fundamental studies of the mechanism of various separation processes, and practical applications of novel radiochemical procedures. The processes include methods of sorption, ion exchange and solvent extraction. Applications to neutron activation analysis, photon electron rejecting alpha liquid scintillation spectrometry and X-ray fluorescence spectrometry are described.     

Conclusions of the workshop

The development of analytical techniques for the determination of chemical species has been one of the fastest growing features of the 90's in analytical chemistry. The need for good quality control of these determinations has led the Measurements and Testing Programme (BCR) to organize several series of interlaboratory studies in the field of speciation analysis over the last five years. The state of the art of speciation analysis was discussed at a first workshop in 1990 (Arcachon, F) and, at this stage, it was deemed necessary to discuss the progress achieved and the trends which should be developed in the near future. A workshop on Trends in Speciation Analysis was therefore held in Rome in February 1994, which allowed recommendations to be made based on round-table discussions. This paper gives a summary of these recommendations in the field of inorganic speciation. Projects currently undertaken in the field of inorganic speciation within the Measurements and Testing Programme are also described. An outline of the programme along with the panel of experts participating in this workshop is given in the appendix.     

Conclusions of the workshop

The development of analytical techniques for the determination of chemical species has been one of the fastest growing features of the 90's in analytical chemistry. The need for good quality control of these determinations has led the Measurements and Testing Programme (BCR) to organize several series of interlaboratory studies in the field of speciation analysis over the last five years. The state of the art of speciation analysis was discussed at a first workshop in 1990 (Arcachon, F) and, at this stage, it was deemed necessary to discuss the progress achieved and the trends which should be developed in the near future. A workshop on Trends in Speciation Analysis was therefore held in Rome in February 1994, which allowed recommendations to be made based on round-table discussions. This paper gives a summary of these recommendations in the field of inorganic speciation. Projects currently undertaken in the field of inorganic speciation within the Measurements and Testing Programme are also described. An outline of the programme along with the panel of experts participating in this workshop is given in the appendix.     

Distribution of major,minor and trace elements in Antarctic offshore and Coastal seawaters: correlation among sites and variables by pattern recognition

The composition of seawater in the Ross Sea (Antarctica) was investigated. The distribution of heavy metals (Cd, Cu, Fe, Mn, Ni), minor and trace (B, Ba, Li, Sr, Si) and major (Na, K, Ca, Mg) elements in coastal and offshore sites was determined. The samples were collected during the XIII Campaign of the Italian “National Programme of Research in Antarctica”, PNRA, at different depths and different stages of the Antarctic summer. In the subsequent campaign the concentrations in the water top micro-layer, and just below it, were compared. Results are also given for the data treatment by pattern recognition.     

Statistical analysis of thermoanalytical experimental data

A statistical technique based on the Wilcockson criterion is suggested for estimation of the reproducibility of thermoanalytical experiments. Reduction of the whole physicochemical process to a quasi-one-stage process is described.This work was carried out partially with the aid of International Science Foundation (Programme Students and Post-Graduate Students).     

Trace metal speciation in coastal and off-shore sediments from Ross Sea (Antarctica)

The information on total metal concentration in sediments is not sufficient to assess the metal behaviour in the environment, while speciation studies are more effective in estimating environmental impact of contaminated sediments. Concerning metal distribution in Antarctic marine sediments, several studies reported total or extractable (by means of a unique reagent) content, but only few publications dealt with metal speciation.This work presents the total content and speciation pattern of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in 12 cm sediment cores, sampled both in coastal and off-shore sites of the Ross Sea shelf area, within the framework of the Italian National Antarctic Programme (PNRA). The total content results of metals are comparable with the background values and the speciation highlights good environmental quality of the studied areas. Only Cd and Pb, in fact, are present in significative amount in non residual phases (acid-extractable and reducible, respectively).     

Berechnung des Endpunktes potentiometrischer Titrationen mit programmierbaren Tischrechnern

Zusammenfassung Die verschiedenen in der Literatur beschriebenen Näherungsverfahren für die Endpunktsberechnung potentiometrischer Titrationen aus den Potentialdifferenzen bei gleichen Reagensvolumenschritten werden gegenübergestellt und Programme für die Diehl Combitron S beschrieben, die auch auf andere programmierbare Tischrechner übertragen werden können.

---

Computation of the end-point of potentiometric titrations with programmable minicomputers

Some possibilities are described for computing the end-point of potentiometric titrations from the differences of electrode potentials at equal steps of titrant volumes. For different methods from the literature programs for the Diehl-Combitron S are described, which are also useful for programming other minicomputers.

     

UK delivery of traceable chemical measurements in the 21st century: building on the foundation of the VAM programme

The paper discusses the requirements for achieving traceable chemical measurements in the UK. It is emphasised that success will depend on establishing an appropriate UK chemical measurement infrastructure and encouraging reference and field laboratories to make use of it. The demanding requirements of the BIPM Mutual Recognition Arrangement (MRA) also require a point of focus to link UK reference laboratories into international metrology. Two key factors are described which have provided the UK with the means to meet these requirements and which have established a sound basis on which to build a system of traceable chemical measurements in the 21st century. These two factors are LGC's long-standing role as the UK's national centre for analytical chemistry and the development and delivery over many years of the UK's Valid Analytical Measurement (VAM) Programme.     

Smoothing and differentiation of thermogravimetric data of biomass materials

Due to the experimental errors, the chemical effect of minor reactions, and some physical effects of heat and mass transfer, there usually exists much noise in the mass loss data resulted from thermal decomposition experiments, and thus high quality smoothing algorithm plays an important role in obtaining reliable derivative thermogravimetric (DTG) curves required for differential kinetic analysis. In this paper three smoothing methods, i.e. Moving Average smoothing, Gaussian smoothing, and Vondrak smoothing, are investigated in detail for pre-treatment of biomass decomposition data to obtain the DTG curves, and the smoothing results are compared. It is concluded that by choosing reasonable smoothing parameters based on the spectrum analysis of the data, the Gaussian smoothing and Vondrak smoothing can be reliably used to obtain DTG curves. The kinetic parameters calculated from the original TG curves and smoothed DTG curves have excellent agreement, and thus the Gaussian and Vondrak smoothing algorithms can be used directly and accurately in kinetic analysis.This work was sponsored by National Natural Science Foundation of China under Grants 50346038 and 50323005, the China NKBRSF project (No. 2001CB409600), the Anhui Excellent Youth Scientist Fundation (2004–2005), the Specialized Research Fund for the Doctoral Program of Higher Education and the National Key Technologies R&D Programme (2001BA510B09-03).     

Synthesis and identification of hydroxylated metabolites of the anti-estrogenic agent cyclofenil

The detection of metabolites of the anti-estrogenic substance cyclofenil, listed on the World Anti-Doping Agency (WADA) Prohibited List since 2004 is described. Target substances are hydroxylated metabolites, bearing an aliphatic hydroxyl group either in the 2-, 3- or 4-position of the aliphatic ring, in addition to the phenolic functions on the aromatic rings. Structural identification used NMR as well as high-resolution mass spectrometry after nano-electrospray ionisation (ESI). Unambiguous detection of all three synthesised cyclofenil metabolites M1-M3 was done using gas chromatography for separation and electron ionisation mass spectrometry for detection of the per-silylated compounds in comparison with a reference urine deriving from an excretion study within the WADA 2007 Educational Programme.     

Radioactivity standards for environmental monitoring

The low-level radioactivity laboratory in the Radioactivity Section of the National Bureau of Standards, and its work in producing standards for monitoring in the environment, are described. Contribution of the National Bureau of Standards, not subject to copyright.     

A pilot study on the feasibility of the preparation of a new certified reference material based on the Antarctic Scallop Adamussium Colbecki

As foreseen by the Italian National Programme of Research in Antarctica, a preliminary investigation was performed to ascertain the feasibility of the production of a new Certified Reference Material for trace elements based on the bivalve Adamussium colbecki. The scallops sampled in Antarctica during the 1999–2000 Italian scientific expedition were analyzed by inductively coupled plasma atomic emission spectrometry and high-resolution inductively coupled plasma mass spectrometry for their content in selected trace elements (As, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, V and Zn). The certification campaign will be undertaken on the basis of the findings of this feasibility study in close cooperation with the Institute for Reference Materials and Measurements, Joint Research Centre of the European Commission.     

Certified reference materials for the quality control of environmental analysis within the standards,measurements and testing programme (formerly BCR)

A great number of analyses is performed every year, the results of which are used for many purposes, e.g. the quality of goods and food, the status of quality of the environment or the health of patients. The accuracy of these results is a prerequisite for a good interpretation of the data obtained. One of the most powerful tool for achieving quality control of chemical analysis is to use reference materials (RMs) and certified reference materials (CRMs). These materials are necessary for one or more of the following items: method validation (CRMs), monitoring of the state of statistical control (RMs), samples in inter-comparisons (RMs), etc. The requirements and use of RMs and CRMs in chemical analysis are described, with special emphasis on environmental analysis, and some examples of environmental materials currently in production within the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission are given.     

测量方法确认技术及其指标评价

阐述了测量方法确认的方法、指标以及方法确认的6种技术手段；介绍了方法确认技术的9种指标以及指标的获得和评价；指出方法确认技术的重点应放在识别和消除显著影响方面。     

The UK National Marine Analytical Quality Control Scheme

 The approach to analytical quality control adopted for the UK National Marine Analytical Quality Control Scheme is described. The Scheme began in 1991 and is in its fifth year of operation. The aim of the programme of work is to ensure adequate control over the accuracy of analysis, such that the aims of the UK National Marine Monitoring Plan are satisfied. The results of interlaboratory tests for the determination of nutrients in water samples and metals, organic compounds in waters, sediments and biological samples are summarised. Received: 7 October 1996 Accepted: 27 February 1997     

IMEP in support of the comparability of measurement results across the Romanian chemical metrology infrastructure

On the basis of quantitative chemical measurements many important decisions are made in support of legislation or in industrial processes or social aspects. For this reason it is important to improve the quality of chemical measurement results and thus make them comparable and acceptable everywhere. The measurement quality is important to enable an equivalent implementation of the European Union regulations and directives across an enlarged EU. In this context, the European Commission–Joint Research Centre–Institute for Reference Materials and Measurement (EC-JRC-IRMM) set up a programme to improve the scientific basis for metrology in chemistry (MiC) in EU candidate countries in the framework of EU enlargement. Several activities were initiated, such as training, fellowships, sponsoring of seminars, conferences and participation in interlaboratory comparisons. To disseminate measurement traceability, IRMM provides through its International Measurement Evaluation Programme (IMEP) an interlaboratory tool to enable the benchmarking of laboratory performance. IMEP emphasizes the metrological aspects of measurement results, such as traceability and measurement uncertainty. In this way it has become a publicly available European tool for MiC. The Romanian Bureau of Legal Metrology – National Institute of Metrology (BRML-INM) actively supports the participation of Romanian authorized and field laboratories in IMEP interlaboratory comparisons. This paper describes the interest of Romanian laboratories participating in this programme, the analytical and metrological problems that became relevant during these exercises and some actions for improvement. The results from Romanian laboratories participating in IMEP-12 (water), IMEP-16 (wine), IMEP-17 (human serum) and IMEP-20 (tuna fish) are presented. To conclude, the educational and training activities at national level organized jointly by the Romanian National Institute of Metrology (INM) and IRMM are also mentioned.     

SI-traceable values for cadmium concentration in the water samples of IMEP-6

 The certification measurement for the cadmium concentration in the samples as performed by Isotope Dilution (ID) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is described in framework of the International Measurement Evaluation Programme (IMEP). By using a primary method of measurement (ID), making up a full uncertainty budget and using a sensitive technique (ICP-MS), reference values traceable to SI can be obtained for this material. The uncertainty budget is performed in accordance with the ISO and EURACHEM guides on uncertainty. A comparison is made with certification results of other experienced laboratories also using primary methods where possible. Received: 8 July 1996/Revised 26 August 1996/Accepted: 1 September 1996