In the near future, research on new materials for radon barriers can be expected to rise in order to meet a greater demand of radon mitigation solutions because of the increasingly lower radon levels ...that the EU legislation aims to. Such research would need a method for the determination of the radon diffusion coefficient and this paper presents an inexpensive method for that purpose, using affordable radon detectors and a simple experimental setup that does not require any tubing or any pumping. Besides the use of two Electronic Integration Devices as radon detectors, the experimental setup used in our method consists only in a two-chamber container made of steel and a small-sized radon source, which was produced in our lab using a 226Ra solution. The radon diffusion coefficient is determined by measuring radon levels in both chambers of the container, which are separated by a membrane made of the material whose radon diffusion coefficient is to be determined. Radon diffuses from a source chamber to a receiver chamber trough the membrane, being the amount of radon that has passed through and the rate at which it has done so the key parameters in the calculation of the radon diffusion coefficient. Our method can handily measure materials with a radon diffusion coefficient above or equal to 10-11 m2 s-1 or, provided that the sample is thin enough, verify that the coefficient is lower than 10-12 m2 s-1. Its precision is good enough to provide radon coefficient diffusion values with a good repeatability as the RSD is as low as a 35% for materials in which the coefficient is in the order of 10-11 m2 s-1. This means that our method is valid for screening materials for radon barriers and checking their compliance with technical specifications.
Display omitted
•New and inexpensive method for the determination of the radon diffusion coefficient, using a simple experimental setup.•Two Electronic Integration Devices are used as radon detectors inside an airtight container, with a small-sized radon source.•This method can measure materials with low radon diffusion coefficients, allowing the screening materials for radon barriers.
Platinum group elements (PGEs) are particularly interesting analytes in different fields, including environmental samples as well as high cost materials that contain them, such as for example ...automotive catalysts. This type of solid samples could be analysed by laser ablation (LA) coupled to ICP-MS, which allow to significantly reducing the analysis time since the time-consuming processes for sample preparation are not required. There is a considerable demand of standards with high PGEs concentration for quantification purposes, which cannot be carried out easily using LA-ICP-MS because the available standards (i.e. NIST SRM 61× series) do not have such analytes in the same concentration range. In this paper, a new strategy is proposed for the synthesis of homogeneous laboratory standards with Pt, Pd and Rh concentrations that range from 77μg/g of Pd up to 2035μg/g of Rh. The proposed strategy is based on the synthesis of monodisperse amino-functionalized amorphous silica nanoparticles, which can retain metal ions. In addition to Pt, Pd and Rh, three lanthanides were also added to the nanoparticles (La, Ce, Nd). Sturdy pressed pellets can be made from the resulting nanopowder without the use of any binder. Elemental composition of standards made of nanoparticles was analysed by conventional nebulization ICP-MS and their homogeneity was successfully evaluated by LA-ICP-MS.
Display omitted
•Robust pellets were prepared by using SiO2 NPs with particle size lower than 50nm.•The NPs were amino-functionalized for retention of high quantities of metal ions.•Two batches of NPs with different metal concentrations were synthesized.•PGEs concentrations were 2–3 orders of magnitude higher than those in NIST SRM 61×.•Homogeneity was studied using LA-ICP-MS technique and good RSDs were found.
Among the different solar cell technologies, amorphous silicon (a-Si:H) thin film solar cells (TFSCs) are today very promising and, so, TFSCs analytical characterization for quality control issues is ...increasingly demanding. In this line, depth profile analysis of a-Si:H TFSCs on steel substrate has been investigated by using pulsed radiofrequency glow discharge-time of flight mass spectrometry (rf-PGD-TOFMS). First, to discriminate potential polyatomic interferences for several analytes (e.g.,
28
Si
+
,
31
P
+
, and
16
O
+
) appropriate time positions along the GD pulse profile were selected. A multi-matrix calibration approach, using homogeneous certified reference materials without hydrogen as well as coated laboratory-made standards containing hydrogen, was employed for the methodological calibration. Different calibration strategies (in terms of time interval selection on the pulse profile within the afterglow region) have been compared, searching for optimal calibration graphs correlation. Results showed that reliable and fast quantitative depth profile analysis of a-Si:H TFSCs by rf-PGD-TOFMS can be achieved.
Graphical Abstract
ᅟ
In recent years particular effort is being devoted to the development of pulsed glow discharges (PGDs) for mass spectrometry because this powering operation mode could offer important ionization ...analytical advantages. However, the capabilities of radiofrequency (RF) PGD coupled to a time of flight mass spectrometry (ToFMS) for accurate isotope ratio measurements have not been demonstrated yet. This work is focused on investigating different time positions along the pulse profile for the accurate measurement of isotope ratios. As a result, a method has been developed for the direct and simultaneous multielement determination of trace elements in powdered geological samples by RF-PGD-ToFMS in combination with isotope dilution mass spectrometry (IDMS) as an absolute measurement method directly traceable to the International System of Units. Optimized operating conditions were 70W of applied radiofrequency power, 250Pa of pressure, 2ms of pulse width and 4ms of pulse period, being argon the plasma gas used. To homogeneously distribute the added isotopically-enriched standards, lithium borate fusion of powdered solid samples was used as sample preparation approach. In this way, Cu, Zn, Ba and Pb were successfully determined by RF-PGD-ToF(IDMS) in two NIST Standard Reference Materials (SRM 2586 and SRM 2780) representing two different matrices of geological interest (soil and rock samples). Cu, Zn, Ba and Pb concentrations determined by RF-PGD-ToF(IDMS) were well in agreement with the certified values at 95% confidence interval and precisions below 12% relative standard deviation were observed for three independent analyses. Elemental concentrations investigated were in the range of 81–5770mg/kg, demonstrating the potential of RF-PGD-ToF(IDMS) for a sensitive, accurate and robust analysis of powdered samples.
A method has been developed for the direct and simultaneous multielement determination of trace elements in powdered geological samples by RF-PGD-ToFMS in combination with isotope dilution mass spectrometry. Display omitted
•An IDMS method for quantification by RF-PGD-ToFMS was investigated.•Some positions along the pulse were studied for accurate isotope ratios measurement.•Lithium borate fusion of powdered solids was used as sample preparation approach.•Cu, Zn, Ba and Pb were successfully determined by RF-PGD-ToF(IDMS) in 2 SRMs.
PDF
