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A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction.
Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment.
Sediments and soils can act as sinks of species of inorganic mercury (Hg2+), while they are simultaneously sources of organic species, such as monomethylmercury (MMHg). Although the fraction of MMHg in total Hg of sediments is suggested to be only 0.1–1%, MMHg poses a threat for humans and wildlife due to its toxic properties, high bioaccumulation potential and the ability to pass the blood-brain barrier. One example of a highly Hg contaminated waterbody is the Finow Canal, the oldest artificial waterway still in operation in Germany. Here, Hg mass fractions of up to 100 µg/g were found in the sediment in previous studies. These are suggested to be associated with a chemical plant producing mercury-based seed dressings. Despite this high mass fraction of Hg, no Hg speciation studies have been conducted there up to now.
In this study, Hg speciation in sediments of Finow Canal at locations before and after the known polluted site was conducted using species-specific isotope dilution (SSID) GC-ICP-ToF-MS. Mass fractions of up to 0.41 µg/g MMHg were determined. In addition, waterbodies around the initially polluted site were investigated and elevated concentrations were also determined around 14 km downstream. For MMHg analysis, the performance of ICP-ToF-MS for SSID GC/ICP-MS was compared with ICP-Q-MS and ICP-SF-MS. Here, isotope ratio precision was similar between the tested instruments. However, the (quasi-) simultaneous detection of the whole mass spectrum will probably offer a much higher precision of ICP-ToF-MS, when more than one isotope system is used.
These results are the first evidence of the occurrence of MMHg in this region and show the need for further investigations of the whole regional ecosystem, as well as the consideration of possible measures of remediation. SSID GC-ICP-(ToF)-MS is a suitable tool for investigating species-specific (multi) isotope systems for environmental monitoring.
The need for quality assessment of anthropogenic impact on environmental pollution is increasing due to discharge from various industries, the use of chemicals in agriculture and the consumption of fossil fuels. Diminishing resources such as natural waters used for the cultivation of agricultural products, plant and animal habitats are under severe pollution pressure and are at constant risk. Several parameters, such as Pb, Cd, Ni, Hg were listed by Water Framework Directive in Directive(2008/105/EC) in the priority substances. Cadmium and Hg were identified as priority hazardous substances whereas As is an important contaminant for its potential toxicological and carcinogenic effects. An inter-comparison study is organised in EURAMET TC-MC in order to demonstrate the capability participants for measuring five elements in river water. The participants carried out measurements for analytes: Pb, Cd, Ni and As as mandatory elements, and Se as an optional one. Participants were asked to perform the measurements with respect to the protocol provided. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.
The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Accurate and precise isotope ratio measurements of heavy elements are playing an increasinglyimportant role in modern analytical sciences and have numerous applications. Today, isotope ratio measurements are typically performed with two principal techniques: thermal ionization mass spectrometry (TIMS) and multiple collector-inductively coupled plasma mass spectrometry (MC-ICP-MS). To obtain accurate results by mass spectrometry, isotopic certified reference materials (iCRMs) are needed for mass bias correction and for the validation of the method used for analysis.Thus, it is of paramount importance to achieve measurement comparability of all data reported, and to assess measurement capability of each CRM producer/National Metrology Institute (NMI). Therefore, the international comparison (CCQM-P213) was performed to assess the analytical capabilities of NMIs for the accurate determination of copper isotope ratio delta values in high purity materials. The study was proposed by the coordinating laboratories, National Research Council Canada (NRC), National Institute of Standards and Technology (NIST), Bundesanstalt für Materialforschung und -prüfung (BAM) and Physikalisch-Technische Bundesanstalt (PTB), as an activity of the Isotope Ratio Working Group (IRWG) of the Consultative Committee for Amount of Substance - Metrology in Chemistry and Biology (CCQM). Participants included six NMIs and one designated institute (DI) from the six countries. Although no measurement method was prescribed by the coordinating laboratories, MC-ICP-MS with either standard-sample bracketing (SSB) or combined SSB with internal normalization (C-SSBIN) models for mass bias correction were recommended. Results obtained from the six NMIs and one DI were in good agreement.
The reference method for obtaining absolute isotope ratios still is the isotope mixture approach. Due the huge efforts required the full isotope mixture approach is applied only by a few institutes worldwide. To enable an IRWG key comparison with a sufficiently large number of participants a proposal for absolute cu isotope ratios is presented where participants will be provided with the enriched isotopes, the isotope mixtures and the samples. In parallel a pilot study will be organized where alternative approaches for obtaining absolute Cu isotope ratios can be applied.
This dataset represents the electronic supplementary material (ESM) of the publication entitled "Characterisation of conventional 87Sr/86Sr isotope ratios in cement, limestone and slate reference materials based on an interlaboratory comparison study", which is published in Geostandards and Geoanalytical Research under the DOI: 10.1111/GGR.12517. It consists of four files. 'ESM_Data.xlsx' contains all reported data of the participants, a description of the applied analytical procedures, basic calculations, the consensus values, and part of the uncertainty assessment. 'ESM_Figure-S1' displays a schematic on how measurements, sequences and replicates are treated for the uncertainty calculation carried out by PTB. 'ESM_Technical-protocol.pdf' is the technical protocol of the interlaboratory comparison, which has been provided to all participants together with the samples and which contains bedside others the definition of the measurand and guidelines for data assessment and calculations. 'ESM_Reporting-template.xlsx' is the Excel template which has been submitted to all participants for reporting their results within the interlaboratory comparison. Excel files with names of the the structure 'GeoReM_Material_Sr8786_Date.xlsx' represent the Rcon(87Sr/86Sr) data for a specific reference material downloaded from GeoReM at the specified date, e.g. 'GeoReM_IAPSO_Sr8786_20221115.xlsx' contains all Rcon(87Sr/86Sr) data for the IAPSO seawater standard listed in GeoReM until 15 November 2022.
Concrete is the most important human-made material because it serves as the basis of our built environment. Since the properties of concretes are dominated by their key compound, cement, devising a way to determine the cement’s origin, known as provenancing, is of great importance for answering different provenance-related questions. These questions range from liability issues when damage occurs to concrete-made structures, to forensic investigations where cement particles are found at crime scenes. This thesis showcases the use of isotope techniques to answer these provenance-related questions. Conventional 87Sr/86Sr and 143Nd/144Nd isotope and elemental ratios consisting of Ca, Sr, K, Mn, Mg, and Ti are used as fingerprints for ordinary Portland cement (OPC) provenancing. The first part of this thesis describes research previously conducted in fingerprinting cementitious materials, providing an overview of provenance studies of cement and the main approaches commonly used. In several studies, the origin of clinker for certain locations was determined via different approaches. However, clinker is an intermediate product, which is available only at the production site and therefore, the practical relevance is rather limited. Furthermore, the use of Sr and Nd isotope systems, together with elemental fingerprints are presented as state of the art in the field. Therein, the principal approach for the overall study is sketched. For the second part of the study, a sample preparation technique for Sr isotopes in Portland cement was developed. The aim was to find the most appropriate sample preparation procedure for cement provenancing and selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated OPCs with those of the corresponding clinkers. Based on these findings, the third part of the study focused on the measurements of Sr and Nd isotope ratios, together with elemental ratios, to establish a reliable technique for OPC provenancing. The outcomes of this final stage are then used to establish a procedure for fingerprinting cements. This becomes possible with the use of Sr and Nd isotope ratios and geochemical profiles. To perform isotope ratio measurements and obtain reliable data, it was necessary to establish a quality control procedure. Thus, an interlaboratory comparison (ILC) was organised to characterise 87Sr/86Sr isotope ratios in geological and industrial reference materials by applying the conventional method for 87Sr/86Sr isotope ratios. As reference material, four cements (VDZ 100a, VDZ 200a, VDZ 300a, IAG OPC-1), one limestone (IAG/CGL ML-3) and one slate (IAG OU-6) were selected, thus covering a wide range of Sr isotope signatures.
The variation of isotope ratios is increasingly used to unravel natural and technical questions. With new upcoming techniques and research topics in the last two decades, such as material provenance or food authenticity to animal and human migration studies, the number of published isotope data has strongly increased. Here, isotope reference materials are indispensable to enable a reliable method validation or even SI-traceability. The fast development and broad availability of inductively coupled plasma mass spectrometry instrumentation (ICP-MS) also lead to an expansion of the classical research areas and new elements are under investigation. Owing to this large expansion of the field, the production and certification of isotope reference materials for calibration and validation is lagging behind, even for classical applications such as conventional 87Sr/86Sr isotope ratio analysis. To improve this situation, BAM organized an interlaboratory comparison (ILC) comprising of thirteen international laboratories for the characterisation of 87Sr/86Sr isotope ratios in geochemical and industrial reference materials. Six reference materials (four cements and two rocks) were provided as powder requiring extensive sample preparation prior to isotopic measurement. Additional requirements included the use of the conventional method for obtaining 87Sr/86Sr isotope ratios, also known as radiogenic 87Sr/86Sr isotope ratios, and the assessment of the measurement uncertainty. The primary goal was to evaluate potential differences in the application of multicollector thermal ionization mass spectrometry (MC-TIMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) for conventional 87Sr/86Sr isotope ratio determination, with a secondary goal to provide reference values for the 87Sr/86Sr isotope ratios in these potential new reference materials. All reported results are accompanied by an uncertainty statement and are traceable to the conventional method, which will be described in detail within this presentation. Current state-of-the-art statistical models were used to ensure the proper evaluation of the reported results and their associated measurement uncertainties within the frame of this ILC. Combined with results from appropriate homogeneity assessment, reference values for 87Sr/86Sr isotope ratios will be assigned.
Pb isotope ratio analysis
(2023)