Filtern
Erscheinungsjahr
Dokumenttyp
- Vortrag (116)
- Zeitschriftenartikel (98)
- Posterpräsentation (25)
- Forschungsbericht (11)
- Beitrag zu einem Sammelband (9)
- Beitrag zu einem Tagungsband (7)
- Buchkapitel (3)
- Sonstiges (2)
- Forschungsdatensatz (1)
Schlagworte
- Traceability (35)
- Metrology (32)
- IDMS (19)
- Absolute isotope ratio (18)
- Isotope ratio (17)
- Uncertainty (17)
- CCQM (11)
- Measurement uncertainty (11)
- ICP-MS (10)
- Reference material (10)
- TIMS (10)
- Delta value (9)
- ICPMS (8)
- Isotope reference materials (8)
- Mass spectrometry (8)
- Copper (7)
- Reference materials (7)
- Cement (6)
- Comparability (6)
- Isotope fractionation (6)
- Isotope reference material (6)
- Metrology in chemistry (6)
- Atomic weight (5)
- Certification (5)
- Conventional isotope ratio (5)
- Delta reference materials (5)
- Herkunft (5)
- Isotope amount ratio (5)
- Isotope dilution (5)
- Magnesium (5)
- Purity (5)
- Sulfur (5)
- Triple isotope fractionation (5)
- Boron isotopes (4)
- Cadmium (4)
- Delta scale (4)
- Human serum (4)
- Interlaboratory comparison (4)
- Isotope (4)
- Isotope delta value (4)
- Isotope dilution mass spectrometry (4)
- Isotope ratios (4)
- Lead (4)
- MC-ICP-MS (4)
- Molar mass (4)
- Provenance (4)
- Purity assessment (4)
- SI traceability (4)
- Stable isotopes (4)
- Zinc (4)
- Archaeometry (3)
- Boron isotope variations (3)
- Delta values (3)
- Delta-scale (3)
- Iron (3)
- Isotopes (3)
- Lead isotopes (3)
- Palladium (3)
- Platinum (3)
- Synthetic isotope mixtures (3)
- Automotive exhaust emissions (2)
- Biodiesel (2)
- Biodiesel fuel (2)
- Bor (2)
- Boron (2)
- Boron isotope fractionation (2)
- CMC (2)
- CRM (2)
- Calibration (2)
- Circular economy (2)
- Geochemistry (2)
- Geological material (2)
- IRM (2)
- Isotope Dilution (2)
- Isotope delta (2)
- Isotopenverhältnisse (2)
- Lithium (2)
- Magnesium isotope ratios (2)
- Metrology in Chemistry (2)
- Milk (2)
- Provenance studies (2)
- SI (2)
- SI-traceability (2)
- Silicon (2)
- Soil (2)
- Sr isotopes (2)
- Surface analysis (2)
- TCE (2)
- Tetramethylammonium hydroxide (2)
- Transferrin (2)
- Uncertainty budget (2)
- boron (2)
- metrology (2)
- traceability (2)
- 87Sr/86Sr (1)
- AAS (1)
- Absolute Isotopenverhältnisse (1)
- Absolute isotope abundance (1)
- Algorithms (1)
- Alzheimer disease (1)
- Alzheimer’s disease (1)
- Amyloid-beta (1)
- Analyte-matrix separation (1)
- Analytical Chemistry (1)
- Analytical uncertainty (1)
- Antikensammlung Berlin (1)
- App (1)
- Archaeology (1)
- Archäometrie (1)
- Areal density (1)
- Argon (1)
- Ash content (1)
- Atomic Absorption Spectrometry (1)
- Atomic absorption spectrometry (1)
- Atomic weights (1)
- Authenticity (1)
- Automotive pollution (1)
- Avogadro constant (1)
- Bell (1)
- Bell pepper (1)
- Bioapatite (1)
- Biogenic carbonates (1)
- Biological boron recycling (1)
- Blank characterization (1)
- Blei (1)
- Blei-Isotopie (1)
- Bodenanalyse (1)
- Boron isotope (1)
- Boron isotopes in food (1)
- Boron isotopic composition (1)
- Boron monohydride (1)
- Boron transport (1)
- Brain (1)
- Branching ratio (1)
- Brassica napus (1)
- CCQM-P107 (1)
- CE/MC-ICP-MS (1)
- Calcification (1)
- Calcium (1)
- Catalytic converters (1)
- Cationic exchange (1)
- Cattle (1)
- Cconventional method (1)
- Cd mass fraction (1)
- Central Taurus (1)
- Cheese (1)
- Chenopodium album (1)
- Chromium (1)
- Ciaaw.org (1)
- Classical oven-drying (1)
- Classical primary measurement method (CPM) (1)
- Commercial moisture analyzer (1)
- Comparison (1)
- Conventional isotope ratios (1)
- Conventional method (1)
- Counting detector (1)
- Cross sections (1)
- Cu-64 (1)
- Curse tablets (1)
- Dairy cows (1)
- Data processing (1)
- Dead time (1)
- Degree of equivalence (1)
- Delta isotope standard (1)
- Delta notation (1)
- Delta-RM (1)
- Dementia (1)
- Detector deadtime (1)
- Determination of metrology of new cadmium atomic weight (1)
- Development (1)
- Diagenesis (1)
- Direct metal assay (1)
- Dissolution (1)
- Double IDMS (1)
- Double isotope dilution (1)
- Dual mode detector (1)
- EPMA (1)
- ERM (1)
- EURAMET (1)
- Elemental composition (1)
- Elemental fingerprints (1)
- Elemental mass spectrometry (1)
- Elementanalyse (1)
- Emissionen (1)
- Enriched isotope (1)
- Environmental pollution monitoring (1)
- Erythrocytes (1)
- Faecal monitoring (1)
- Feed (1)
- Feeding regime (1)
- Finow Canal (1)
- Fluchtafel (1)
- Food (1)
- Fossil fuel (1)
- Fuel (1)
- Fundamental science (1)
- GDMS (1)
- Graphite furnace (1)
- Gravimtric isotope mixtures (1)
- Greek curse tablets (1)
- Green Deal (1)
- Gypsum (1)
- HR-CS-MAS (1)
- Hafnium (1)
- Heavy metals (1)
- High purity metals (1)
- High-fired gypsum mortar (1)
- High-purity elements (1)
- High-resolution continuum source absorption spectrometry (1)
- High-resolution continuum source graphite furnace atomic absorption spectrometry (1)
- Hydrothermal fluid (1)
- Hyphenated (1)
- ICP-OES (1)
- ICP-TOFMS (1)
- ICP-ToF-MS (1)
- ID-ICP-MS (1)
- ID-MS (1)
- ILC (1)
- IMEP-9 (1)
- IUPAC Inorganic chemistry division (1)
- Iinductively coupled plasma mass spectrometry (1)
- Impurities (1)
- Impurity assessment (1)
- Impurity assessment approach (1)
- In-house calibration solution (1)
- Inductively coupled plasma (ICP) mass spectrometry (1)
- Inorganic chemical analysis (1)
- Inorganic impurities (1)
- Instrumental isotope fractionation (1)
- Interferences (1)
- Intra-plant isotope variability (1)
- Iridium (1)
- Iron isotope fractionation (1)
- Isobaric interferences (1)
- Isotope abundance (1)
- Isotope amount ratios (1)
- Isotope mixture (1)
- Isotope mixtures (1)
- Isotope purification (1)
- Isotope ratio mass spectrometry (1)
- Isotopenverhältnisse Strontium und Blei (1)
- Isotopenzusammensetzung (1)
- Isotopic Reference Material (1)
- Isotopic abundance variations (1)
- Isotopic analysis (1)
- Isotopic composition (1)
- Isotopic fractionation (1)
- Kalke (1)
- Karl Fischer titration (1)
- Kernkraftwerk (1)
- Kernkraftwerke (1)
- Kilogram (1)
- Königswasserextraktion (1)
- LA-(MC-)ICP-MS (1)
- LA-ICP-MS (1)
- LSVEC (1)
- Lagerstätten (1)
- Laser ablation (1)
- Lead isotope composition (1)
- Lead isotope ratios (1)
- Lead isotope variations (1)
- Lead isotopic composition (1)
- Legacy pollution (1)
- Low sulfur (1)
- MC-TIMS (1)
- MDG (1)
- MW-AES (1)
- Machine learning (1)
- Magnesium absorption (1)
- Magnesium stable isotopes (1)
- Mangesium (1)
- Mass discrimination (1)
- Mass fractionation (1)
- Massenspektrometrie (1)
- Matrix samples (1)
- Matrix separation (1)
- Measurement space (1)
- Measuremment uncertainty (1)
- Memory effect (1)
- Mercury (1)
- Mercury speciation (1)
- Metal assay approach (1)
- Metal sublimation (1)
- Methylmercury (1)
- Micro-sublimation (1)
- Microbially induced corrosion (1)
- Mittelalterliche Pilgerzeichen (1)
- Moisture (1)
- Mole (1)
- Molecular absorption (1)
- Multi-collector ICP-MS (1)
- Multi-collector inductively coupled plasma-mass spectrometry (ICP-MS) (1)
- Multi-element screening (1)
- Multicollector inductively coupled plasma mass spectrometry (1)
- NTD (1)
- Nanoparticles (1)
- Neutron activation (1)
- Neutron transmutation doping (1)
- Nickel (1)
- Nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (1)
- Noise (1)
- Non-metal analysis (1)
- Open vessel digestion (1)
- Optimization (1)
- Ore provenance (1)
- PERM (1)
- PGE (1)
- PTI-MS (1)
- Pb isotope ratio thermal ionization mass spectrometry (1)
- Pb isotopes (1)
- Pepper (1)
- Petrol (1)
- Plant metabolism (1)
- Plant tissue (1)
- Plants (1)
- Platinum group elements (PGE) (1)
- Polarised light microscopy (1)
- Polyethylene (1)
- Polypropylene (1)
- Pore fluids (1)
- Portland cement (1)
- Portland clinker (1)
- Priam's treasure (1)
- Primary Isotopic Reference Material (1)
- Primary calibration solution (1)
- Primary difference measurement method (PDM) (1)
- Primary method of measurement (1)
- Primary transfer standards (PTSs) (1)
- Primäres Isotopenreferenzmaterial (1)
- Provenancing (1)
- Purity analysis (1)
- Purity determination (1)
- Quality system (1)
- Quantitative protein analysis (1)
- Radiogenic isotopes (1)
- Raman microspectroscopy (1)
- Raman spectroscopy (1)
- Re-evaluation (1)
- Reference data (1)
- Reference measurement (1)
- Reference measurement procedures (1)
- Reference measurements (1)
- Reference procedure (1)
- Review (1)
- Revision of the SI (1)
- River water (1)
- SF-ICP-MS (1)
- Sample-sample bracketing (1)
- Scale anchor (1)
- Scale conversion (1)
- Schwermetallbestimmung (1)
- Selenium (1)
- Serum (1)
- Silver artefacts (1)
- Single IDMS (1)
- Single Particle (1)
- Soil available boron (1)
- Spike (1)
- Sr and Nd isotope analysis (1)
- Sr isotope analysis (1)
- Stable isotope (1)
- Standard addition (1)
- Standard atomic weight (1)
- Statistical analysis (1)
- Strontium isotope (1)
- Strontium isotope ratio (1)
- Sulfur in oil (1)
- Sulphur (1)
- Sulphur isotope (1)
- Synthetic mixtures (1)
- TIMs (1)
- Tau (1)
- Technology-critical elements (1)
- Terminology (1)
- Thermal ionization mass spectrometry (1)
- Thermionenmassenspektrometrie (1)
- Thermogravimetry (1)
- Total element content (1)
- Total element determination (1)
- Toxic elements (1)
- Transient signal (1)
- Triple IDMS (1)
- Trojan silver artefacts (1)
- Trophic level (1)
- Unsicherheitsvergleiche (1)
- Uranium (1)
- Urinary monitoring (1)
- Urine (1)
- Validate method (1)
- Value assignment (1)
- WD-XRF (1)
- Water (1)
- Wet digestion (1)
- Wood chips (1)
- XRCD method (1)
- Ytterbium (1)
- absolute measurements (1)
- atomic weight (1)
- bell pepper (1)
- collision cell (1)
- delta value (1)
- enriched isotope (1)
- interferences (1)
- isotope fractionation (1)
- isotope ratio (1)
- isotope reference material (1)
- key comparison (1)
- lank characterization (1)
- magnesium (1)
- mass spectrometry (1)
- measurement uncertainty (1)
- metabolism (1)
- multi-collector (1)
- purity (1)
- reference material (1)
- silicon (1)
- species-specific isotope information (1)
- tandard addition (1)
- uncertainty budget (1)
- Ägyptisches Museum Berlin (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (89)
- 1.1 Anorganische Spurenanalytik (89)
- P Präsident (4)
- P.0 Präsident und andere (4)
- 1.3 Instrumentelle Analytik (3)
- 1.4 Prozessanalytik (3)
- 1.6 Anorganische Referenzmaterialien (3)
- S Qualitätsinfrastruktur (3)
- S.1 Qualität im Prüfwesen (3)
- 1.7 Organische Spuren- und Lebensmittelanalytik (2)
- 7 Bauwerkssicherheit (2)
- 7.4 Baustofftechnologie (2)
- 1.5 Proteinanalytik (1)
- 1.8 Umweltanalytik (1)
- 6 Materialchemie (1)
- 6.3 Strukturanalytik (1)
- 7.0 Abteilungsleitung und andere (1)
- PST Präsidiale Stabsstelle (1)
Eingeladener Vortrag
- nein (116)
Previously applied methods for the quantification of sulphur in copper and other pure metals revealed a lack of SI-traceability and additionally showed inconsistent results, when different methods were compared.
Therefore, a reference procedure is required which allows SI-traceable values accompanied by a Sound uncertainty budget. In this study a procedure was developed for the quantification of total sulphur in copper at low concentration levels using inductively coupled plasma-isotope dilution mass spectrometry (ICP-IDMS). The major part of the copper matrix was separated by adding ammonia which forms a complex with the copper while releasing the sulphur followed by chromatographic separation using a weak cation resin. After that the sulphur fraction was further purified by chromatographic means using first an anion exchange method and second a chelating resin. The developed procedure shows high performance, especially concerning high efficiency in matrix removal (>99.999%) while keeping the recovery of sulphur above 80%. Procedure blanks are in the order of 3–53 ng resulting in LOD and LOQ values of 0.2 mg g1 and 0.54 mg g1, respectively. The procedure is sufficient to facilitate value assignment of the total sulphur mass fraction in reference materials. Additionally, relative measurement uncertainties were calculated to be below 1% and the measurement results were traceable to the SI. The procedure reported in this study is a new reference procedure for sulphur measurement in copper, being fit for two major purposes, certification of reference materials and assignment of reference values for inter-laboratory comparison.
The stable carbon and nitrogen isotopic composition of urine and milk samples from cattle under different feeding regimes were analysed over a period of six months. The isotope ratios were measured with isotope ratio mass spectrometry (IRMS). The δ13C values of milk and urine were dependent on different feeding regimes based on C3 or C4 plants. The δ13C values are more negative under grass feeding than under maize feeding. The δ13C values of milk are more negative compared to urine and independent of the feeding regime. Under grass feeding the analysed milk and urine samples are enriched in 13C relative to the feed, whereas under maize feeding the 13C/12C ratio of urine is in the same range and milk is depleted in 13C relative to the diet. The difference between the 15N/14N ratios for the two feeding regimes is less pronounced than the 13C/12C ratios. The δ15N values in urine require more time to reach the new equilibrium, whereas the milk samples show no significant differences between the two feeding regimes.
Boron isotope amount ratios n(10B)/n(11B) have been determined by monitoring the absorption spectrum of boron monohydride (BH) in a graphite furnace using high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Bands (0→0) and (1→1) for the electronic transition X1Σ+ → A1Π were evaluated around wavelengths 433.1 nm and 437.1 nm respectively. Clean and free of memory effect molecular spectra of BH were recorded. In order to eliminate the memory effect of boron, a combination of 2% (v/v) hydrogen gas in argon and 1% trifluoromethane in argon, an acid solution of calcium chloride and mannitol as chemical modifiers was used. Partial least square regression (PLS) for analysis of samples and reference materials were applied. For this, a spectral library with different isotopes ratios for PLS regression was built. Results obtained around the 433.1 nm and 437.1 nm spectral regions are metrologically compatible with those reported by mass spectrometric methods. Moreover, for the evaluated region of 437 nm, an accuracy of 0.15‰ is obtained as the average deviation from the isotope reference materials. Expanded uncertainties with a coverage factor of k = 2 range between 0.15 and 0.44‰. This accuracy and precision are compatible with those obtained by mass spectrometry for boron isotope ratio measurements.
The quantification of the sulphur mass fraction in pure copper and copper alloys by GDMS and LA-ICP-MS revealed a lack of traceability mainly due to a lack of suitable certified reference materials for calibrating the instruments. Within this study GDMS and LA-ICP-MS were applied as routine analytical tools to quantify sulphur in copper samples by applying reference materials as calibrators, which were characterized for their sulphur mass fraction by IDMS beforehand. Different external calibration strategies were applied including a matrix cross type calibration. Both techniques with all calibration strategies were validated by using certified reference materials (others than those used for calibration) and good agreement with the reference values was achieved except for the matrix cross type calibration, for which the agreement was slightly worse. All measurement results were accompanied by an uncertainty statement. For GDMS, the relative expanded (k = 2) measurement uncertainty ranged from 3% to 7%, while for LA-ICP-MS it ranged from 11% to 33% when applying matrix-matched calibration in the sulphur mass fraction range between 25 mg kg-1 and 1300 mg kg-1. For cross-type calibration the relative expanded (k = 2) measurement uncertainty need to be increased to at least 12% for GDMS and to at least 54% for LA-ICP-MS to yield metrological compatibility with the reference values. The so obtained measurement results are traceable to the international system of units (SI) via IDMS reference values, which is clearly illustrated by the unbroken chain of calibrations in the metrological traceability scheme.
The 87Sr/86Sr isotope ratio can, in principle, be used for provenancing of cement. However, while commercial cements consist of multiple components, no detailed investigation into their individual 87Sr/86Sr isotope ratios or their influence on the integral 87Sr/86Sr isotope ratio of the resulting cement was conducted previously. Therefore, the present study aimed at determining and comparing the conventional 87Sr/86Sr isotope ratios of a diverse set of Portland cements and their corresponding Portland clinkers, the major component of these cements. Two approaches to remove the additives from the cements, i.e. to measure the conventional 87Sr/86Sr isotopic fingerprint of the clinker only, were tested, namely, treatment with a potassium hydroxide/sucrose solution and sieving on a 11-µm sieve. Dissolution in concentrated hydrochloric acid/nitric acid and in diluted nitric acid was employed to determine the 87Sr/86Sr isotope ratios of the cements and the individual clinkers. The aim was to find the most appropriate sample preparation procedure for cement provenancing, and the selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated cements with those of the corresponding clinkers. None of the methods to separate the clinkers from the cements proved to be satisfactory. However, it was found that the 87Sr/86Sr isotope ratios of clinker and cement generally corresponded, meaning that the latter can be used as a proxy for the clinker 87Sr/86Sr isotope ratio. Finally, the concentrated hydrochloric acid/nitric acid dissolution method was found to be the most suitable sample preparation method for the cements; it is thus recommended for 87Sr/86Sr isotope analyses for cement provenancing.
Polyethylene (PE) frits were used to quantify sulphur in copper and its alloys by isotope dilution combined with LA-ICP-MS as an alternative approach to conventional sample preparation: the copper samples were spiked, the spiked samples were dissolved, the resulting solutions were absorbed in the PE frits and finally the PE frits were analysed by LA-ICP-MS. A prerequisite for such a support material is a low sulphur blank and thus PE was selected for this purpose. The absorption efficiency of the PE frits was studied for varying sulphur amounts ranging from 2 mg S to 80 mg S showing that more than 99.5% of the loaded sulphur was absorbed by the frit. The so prepared PE frits were measured by LA-ICP-MS and yielded a good linearity (R2 ¼ 0.999) for the sulphur ion intensities corresponding to sulphur amounts up to 40 mg S; the associated sensitivity is approximately 3.4 x 10⁴ cps μg⁻¹ for ³²S. For the validation of the developed procedure the reference materials BAM-M376a, BAM-228 and BAM-227 were applied such that 2 μg S, 5 μg S and 11 μg S were absorbed in the PE frits, respectively. These samples were pre-quantified for the adsorbed sulphur amount by external calibration LA-ICP-MS yielding sulphur amounts of 0.9 μg, 5.1 μg and 8.5 μg (quantified for ³²S only), respectively. Relative Standard deviations of the isotope ratios were below 5% in average (n ¼ 3 lines) in all cases (except for the pure spike solution). These samples were then analysed by LA-ICP-IDMS and the measurement results were validated by comparing them with the results obtained by conventional ICP-IDMS. The obtained relative expanded measurement uncertainties ranged between 10% and 26%. Pearson's coefficient was used to express the correlation between both techniques; the obtained value was 0.999 demonstrating a strong correlation. Contrary to most published LA-ICP-IDMS procedures, the developed procedure enables SI-traceability for the measurement results. The metrological traceability to the SI for the sulphur mass fractions in copper was established by an unbroken chain of comparisons, each accompanied by an uncertainty budget. Thus, the measurement results are considered reliable, acceptable and comparable within the stated measurement uncertainty. The metrological traceability chain from the kg down to mass fraction in the samples obtained by LA-ICP-IDMS is presented as well.
In this study, an analytical procedure for multi-element screening of 40 elements in milk and feed samples was developed. Three different digestion and two different calibration methods were tested for the best suitability. The analytical procedure for the quantification of minor and trace elements is based on sector field ICP-MS (SF-ICP-MS). The method validation revealed good agreement between the determined elemental mass fractions and the certified values of two milk and three feed reference materials. Milk samples of dairy cows at different feeding regimes were collected from two different farms. The results of our study showed significant differences of nine elemental mass fractions (Li, P, Mn, Co, Cu, Rb, Sr, Br, I) between milk from the two locations. Further, a correlation between the elemental mass fractions of milk and the ingested feed and water was observed.
The therapeutic dose of lithium (Li) compounds, which are widely used for the treatment of psychiatric and hematologic disorders, is close to its toxic level; therefore, drug monitoring protocols are mandatory. Herein, we propose a fast, simple, and low-cost analytical procedure for the traceable determination of Li concentration in human serum, based on the monitoring of the Li isotope dilution through the partially resolved isotope shift in its electronic transition around 670.80 nm using a commercially available high-resolution continuum source graphite furnace atomic absorption spectrometer. With this technique, serum samples only require acidic digestion before analysis. The procedure requires three measurements—an enriched 6Li spike, a mixture of a certified standard solution and spike, and a mixture of the sample and spike with a nominal 7Li/6Li ratio of 0.82. Lanthanum has been used as an internal spectral standard for wavelength correction. The spectra are described as the linear superposition of the contributions of the respective isotopes, each consisting of a spin-orbit doublet, which can be expressed as Gaussian components with constant spectral position and width and different relative intensity, reflecting the isotope ratio in the sample. Both the spectral constants and the correlation between isotope ratio and relative band intensity have been experimentally obtained using commercially available materials enriched with Li isotopes. The Li characteristic mass (mc) obtained corresponds to 0.6 pg. The procedure has been validated using five human serum certified reference materials. The results are metrologically comparable and compatible to the certified values. The measurement uncertainties are comparable to those obtained by the more complex and expensive technique, isotope dilution mass spectrometry.
An alternative method for lithium isotope amount ratio analysis based on a combination of high-resolution atomic absorption spectrometry and spectral data analysis by machine learning (ML) is proposed herein. It is based on the well-known isotope shift of approximately 15 pm for the electronic transition 22P←22S at around the wavelength of 670.8 nm, which can be measured by the state-of-the-art high-resolution continuum source graphite furnace atomic absorption spectrometry. For isotope amount ratio analysis, a scalable tree boosting ML algorithm (XGBoost) was employed and calibrated using a set of samples with 6Li isotope amount fractions, ranging from 0.06 to 0.99 mol mol–1, previously determined by a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). The calibration ML model was validated with two certified reference materials (LSVEC and IRMM-016). The procedure was applied toward the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, and LiOH) and a BAM candidate reference material NMC111 (LiNi1/3Mn1/3Co1/3O2), a Li-battery cathode material. The results of these determinations were compared with those obtained by MC-ICP-MS and found to be metrologically comparable and compatible. The residual bias was −1.8‰, and the precision obtained ranged from 1.9 to 6.2‰. This precision was sufficient to resolve naturally occurring variations, as demonstrated for samples ranging from approximately −3 to +15‰. To assess its suitability to technical applications, the NMC111 cathode candidate reference material was analyzed using high-resolution continuum source atomic absorption spectrometry with and without matrix purification. The results obtained were metrologically compatible with each other.
In this study, we demonstrate the applicability of nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for Ca, Fe, and Se quantification in human serum using isotope dilution (ID) analysis. The matrix tolerance of MICAP-MS in Na matrix was investigated, uncovering that high Na levels can suppress the signal intensity. This suppression is likely due to the plasma loading and the space charge effect. Moreover, 40Ca and 44Ca isotopic fractionation was noted at elevated Na concentration. Nine certified serum samples were analyzed using both external calibration and ID analysis. Overestimation of Cr, Zn, As, and Se was found in the results of external calibration, which might be resulted from C-induced polyatomic interference and signal enhancement, respectively. Further investigations performed with methanol showed a similar enhancement effect for Zn, As, and Se, potentially supporting this assumption. The mass concentrations determined with ID analysis show metrological compatibility with the reference values, indicating that MICAP-MS combined with ID analysis can be a promising method for precise Ca, Fe, and Se determination. Moreover, this combination reduces the influences of matrix effects, broadening the applicability of MICAP-MS for samples with complex matrix.
This Report describes the certification of the reference material antimony implanted in Si/SiO2 intended to be used for calibration of surface and near surface analytical methods. It describes the preparation, homogeneity measurements and the analytical work performed for the certification of both Areal density of antimony Atoms (retained dose) and the isotope amount Ratio as well as giving considerations on the stability of the material.
In the past, δ26/24Mg measurements were referenced to NIST SRM 980, the initial zero of the δ26/24Mg scale. With the development of MC-ICPMS, the detection of small but measurable isotopic differences in different chips of SRM 980 became apparent. To solve this problem a suite of magnesium isotope reference materials, ERM-AE143, -AE144 and -AE145, has been certified in a first study by applying an ab initio calibration for absolute Mg isotope ratios without any a priori assumptions, a procedure which fulfils all requirements of a primary method of measurement. We could achieve for the first time measurement uncertainties for isotope amount ratios close to the typical precision of magnesium delta values, δ26/24Mg, which are at the 0.1 ‰ level (2SD). In addition, it was demonstrated that commonly used fractionation laws are invalid for correcting Mg isotope ratios in multi-collector ICPMS as they result in a bias which is not covered by its associated uncertainty. Depending on their type, fractionation laws create a bias up to several per mil, with the exponential law showing the smallest bias between 0.1 ‰ to 0.7 ‰.
With these isotope reference materials, it is possible to establish SI-traceability for magnesium delta measurements. To realize this, we organized a second study within which five expert laboratories participated to cross-calibrate all available magnesium isotope standards, which are NIST SRM 980, IRMM-009, ERM-AE143, ERM-AE144, ERM-AE145 and the standards DSM3 and Cambridge-1. The mean δ26/24Mg values for the individual iRMs, calculated from the laboratory means show 2 SD reproducibilities varying between 0.025 and 0.093 ‰. Propagated measurement uncertainties suggest a standard uncertainty of about 0.1‰ for δ26/24Mg determinations (2SD). Thus, SI traceability for magnesium isotope amount ratios and delta values is demonstrated to be established.
The platinum group elements (PGEs) play an important role in reducing emissions from automotive vehicles through their use in catalytic convertors but also for catalysis in the pharmaceutical industry. The immense economic value of platinum (Pt), palladium (Pd) and rhodium (Rh) highlights the importance of highly accurate measurements. Therefore, there is a need for National Metrology Institutes (NMIs) and Designated Institutes (DIs) to demonstrate measurement capability in this space.
A pilot comparison (CCQM-P63) for precious metals in automotive catalyst took place in 2006, but with a limited number of institutes participating. Furthermore, this study was performed over 17 years ago. Therefore, there was a need to maintain existing capability and demonstrate new capability in a key comparison, in order to claim calibration and measurement capability claims (CMCs). With the core capability matrix, this study falls into the "Difficult to dissolve metals/metal oxides" which will support CMC categories 8 (Metal and metal alloys), 9 (Advanced materials) and 14 (Other materials).
Eleven NMIs and DIs participated in the Key Comparison CCQM-K160 Platinum Group Elements in Automotive Catalyst. Participants were requested to evaluate the mass fractions of Pt, Pd and Rh in mg/kg in an unused autocatalyst material (cordierite ceramic base). The Key Comparison Reference Values (KCRVs) and Degrees of Equivalence (DoEs) were calculated utilising the NIST Decision Tree for the measurands. The participants utilised a number of sample preparation and analytical methods including hot plate digestion, microwave digestion and sodium fusion, followed by either atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectroscopy (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS) detection. Several calibration techniques were used, namely external calibration, standard addition, isotope dilution mass spectrometry (IDMS) and an exact matching procedure. Additionally, one participant employed instrumental neutron activation analysis (INAA) with k0 standardisation which is a direct solid analysis method. The majority of participants claimed traceability to NIST primary calibrants or their own CRMs. Furthermore, several matrix CRMs were included or spiked samples for quality control. All institutes were required to determine the dry mass fraction using the stipulated protocol.
The NIST decision tree was implemented for the calculation of the KCRVs and DoEs. The participant results overall showed good agreement with the KCRV, despite the variety of dissolution procedures and measurement techniques for this highly complex matrix and challenging measurands. Successful participation in CCQM-K160 demonstrated measurement capabilities for the determination of mass fraction of Pt, Pd and Rh in the mg/kg range and will support broad scope CMC claims for a wide range of challenging matrices.
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).
We report an appropriate preparation of binary isotope calibration mixtures of the three stable isotopes of magnesium to be used in the ab initio calibration of multicollector mass spectrometers (ICPMS and TIMS). For each of the three possible combinations of binary mixtures ("24Mg" + "25Mg", "24Mg" + "26Mg", and "25Mg" + "26Mg"), three individual setups have been prepared under gravimetric control, each of them with an isotope ratio close to unity, and a total magnesium mass fraction close to 20 mg kg-1. The preparation was designed to occur via an intermediate dilution of a parent solution of a highly purified specimen of the isotopically enriched magnesium materials. For the application as calibration mixtures, a complete uncertainty budget was set up, and is presented and discussed in detail, including the aspects that went into the design of the dilution and mixing approach to minimize uncertainty. The principle parameters for the purpose of the later calibration of the mass spectrometers are the absolute masses of isotopically enriched magnesium materials in the primary calibration mixtures. For the first time relative expanded uncertainties U (k = 2) for these masses of ≤0.005% could be achieved for all mixtures.
For the first time, an ab initio calibration for absolute Mg isotope ratios was carried out, without making any a priori assumptions. All quantities influencing the calibration such as the purity of the enriched isotopes or liquid and solid densities were carefully analysed and their associated uncertainties were considered. A second unique aspect was the preparation of three sets of calibration solutions, which were applied to calibrate three multicollector ICPMS instruments by quantifying the correction factors for instrumental mass discrimination. Those fully calibrated mass spectrometers were then used to determine the absolute Mg isotope ratios in three candidate European Reference Materials (ERM)-AE143, -AE144 and -AE145, with ERM-AE143 becoming the new primary isotopic reference material for absolute isotope ratio and delta measurements. The isotope amount ratios of ERM-AE143 are n(25Mg)/n(24Mg) = 0.126590(20) mol/mol and n(26Mg)/n(24Mg) = 0.139362(43) mol/mol, with the resulting isotope amount fractions of x(24Mg) = 0.789920(46) mol/mol, x(25Mg) = 0.099996(14) mol/ mol and x(26Mg) = 0.110085(28) mol/mol and an atomic weight of Ar(Mg) = 24.305017(73); all uncertainties were stated for k = 2. This isotopic composition is identical within uncertainties to those stated on the NIST SRM 980 certificate. The candidate materials ERM-AE144 and -AE145 are isotopically lighter than ERM-AE143 by 1.6 ‰ and 1.3 ‰, respectively, concerning their n(26Mg)/n(24Mg) ratio. The relative combined standard uncertainties are ≤0.1 ‰ for the isotope ratio n(25Mg)/n(24Mg) and ≤0.15 ‰ for the isotope ratio n(26Mg)/ n(24Mg). In addition to characterizing the new isotopic reference materials, it was demonstrated that commonly used fractionation laws are invalid for correcting Mg isotope ratios in multicollector ICPMS as they result in a bias which is not covered by its associated uncertainty. Depending on their type, fractionation laws create a bias up to several per mil, with the exponential law showing the smallest bias between 0.1 ‰ and 0.7 ‰.