Chemische Charakterisierung und Spurenanalytik
Filtern
Dokumenttyp
- Zeitschriftenartikel (36)
- Vortrag (22)
- Posterpräsentation (2)
Schlagworte
- Traceability (15)
- Absolute isotope ratio (12)
- Metrology (11)
- Uncertainty (11)
- Isotope ratio (8)
- Cement (5)
- Delta value (5)
- Triple isotope fractionation (5)
- Copper (4)
- Isotope dilution (4)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (60)
- 1.1 Anorganische Spurenanalytik (60)
- 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 (22)
The gravimetric isotope mixture method is the primary method to determine absolute isotope ratios. This method, however, depends on the existence of suitable spike materials and knowledge of their purities. Determining the purity of the spikes can be tedious and labour-intensive. In this publication, an advancement of the gravimetric isotope mixture method, rendering the determination of the purity of the spike materials unnecessary, is presented. The advancement combines mass spectrometry and ion chromatography leading to an approach being independent of the purity of the spike materials. In the manuscript the mathematical background and the basic idea of the novel approach are described using a two-isotope system like copper or lithium.
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).
Soil certified reference material (CRM), UME EnvCRM 03 was produced by a collaborative approach among national metrology institutes, designated institutes and university research laboratories within the scope of the EMPIR project: Matrix Reference Materials for Environmental Analysis. This paper presents the sampling and processing methodology, homogeneity, stability, characterization campaign, the assignment of property values and their associated uncertainties in compliance with ISO 17034:2016. The material processing methodology involves blending a natural soil sample with a contaminated soil sample obtained by spiking elemental solutions for 8 elements (Cd, Co, Cu, Hg, Ni, Pb, Sb and Zn) to reach the level of warning risk monitoring values specified for metals and metalloids of soils in Europe. Comparative homogeneity and stability test data were obtained by two different institutes, ensuring the reliability and back up of the data. The certified values and associated expanded uncertainties for the total mass fractions of thirteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, V and Zn) are established. The developed CRM can be used for the development and validation of measurement procedures for the determination of the total mass fractions of elements in soil and also for quality control/assurance purposes. The developed CRM is the first example of a soil material originating from Türkiye.
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.
We report an analytical methodology for the quantification of sulfur in biological molecules via a speciesunspecific postcolumn isotope dilution (online ID) approach using capillary electrophoresis (CE) coupled online with inductively coupled plasma−mass spectrometry (online ID CE/ICP−MS).
The method was optimized using a mixture of standard compounds including sulfate, methionine, cysteine, cystine, and albumin, yielding compound recoveries between 98 and 105%. The quantity of sulfur is further converted to the quantity of the compounds owing to the prior knowledge of the sulfur content in the molecules. The limit of detection and limit of quantification of sulfur in the compounds were 1.3−2.6 and 4.1−8.4 mg L−1, respectively, with a correlation coefficient of 0.99 within the concentration range of sulfur of 5−100 mg L−1. The capability of the method was extended to quantify albumin in its native matrix (i.e., in serum) using experimentally prepared serum spiked with a pure albumin standard for validation. The relative expanded uncertainty of the method for the quantification of albumin was 6.7% (k = 2). Finally, we tested the applicability of the method on real samples by the analysis of albumin in bovine and human sera. For automated data assessment, a software application (IsoCor) which was developed by us in a previous work was developed further for handling of online ID data. The method has several improvements compared to previously published setups: (i) reduced adsorption of proteins onto the capillary wall owing to a special capillary-coating procedure, (ii) baseline separation of the compounds in less than 30 min via CE, (iii) quantification of several sulfur species within one run by means of the online setup, (iv) SI traceability of the quantification results through online ID, and (v) facilitated data processing of the transient signals using the IsoCor application. Our method can be used as an accurate approach for quantification of proteins and other biological molecules via sulfur analysis in complex matrices for various fields, such as environmental, biological, and pharmaceutical studies as well as clinical diagnosis.
Sulfur is an essential element in living organisms, where it plays important roles in various biological processes, such as protein synthesis, enzyme activity, and antioxidant defense. However, the biological effects of different sulfur species can vary widely, and imbalances in sulfur speciation have been observed in a range of diseases, including cancer, Alzheimer’s disease, and diabetes.1−3 The accurate quantification of sulfur and its species in biological samples requires sensitive and selective analytical techniques. In recent years, separation techniques coupled online with inductively coupled plasma−mass spectrometry (ICP−MS) have emerged as powerful online analytical tools complementary to molecular spectrometric methods for speciation analysis of biological compounds.
External calibration4−9 and isotope dilution (ID)10−15 are common calibration approaches applied for online quantification of sulfur species in complex samples. The ID analysis is advantageous over.
Sr isotope ratio analysis
(2023)
Pb isotope ratio analysis
(2023)
Detector deadtime
(2023)