Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and micrometer-sized carbon-based particles such as microplastics. However, its applicability to the measurement of micrometer-sized non-carbon-based particles such as silica (SiO) particles is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO microspheres with a nominal diameter of 5.
View Article and Find Full Text PDFSingle particle inductively coupled plasma mass spectrometry has been used for size measurements of individual nanoparticles (NPs). Here, uncertainties in size analysis based upon two calibration approaches were evaluated: (i) the use of particle size standard and (ii) the use of ion standard solution. For particle size standard approach, the source of uncertainty to determine the target NP diameter was related to the variation in the signal intensities of both target NPs and particle size standard, and the size distribution of the particle size standard.
View Article and Find Full Text PDFIridium (Ir) is one of the rarest elements in the Earth's crust and is valuable in industry due to its high corrosion resistance. In this study, we used lyophilized cells of a unicellular red alga, for the selective recovery of small amounts of Ir from hydrochloric acid (HCl) solutions. The Ir recovery efficiency of the lyophilized cells was higher than that of activated carbon and comparable to that of an ion-exchange resin in up to 0.
View Article and Find Full Text PDFThis study investigates the biosorption mechanism, including cell population behavior, of trace amounts of precious metals (gold, palladium, and platinum) in a unicellular red alga, Galdieria sulphuraria. Single-cell inductively coupled plasma mass spectrometry showed that the number of adsorbing cells and the concentration of adsorbed metal per cell varied depending on solution acidity and metal species. The X-ray absorption fine structure in 5 mM HCl solution indicated that the adsorbed Au formed inner-sphere complexes with S, whereas the adsorbed Pd and Pt formed an inner-sphere complexes with N and/or S.
View Article and Find Full Text PDFThe high electrical conductivity, chemical stability, and low toxicity of elemental Au make it a highly valuable resource. However, wastewater produced during the mining, utilization, and disposal of Au inevitably contains small amounts (10-40 mg L) of Au, thus posing environmental risks. It is too acidic to be treated with inexpensive and eco-friendly bioadsorbents previously studied for the remediation of less acidic effluents.
View Article and Find Full Text PDFThe separation properties of arsenic species was investigated using HPLC-ICP-MS with several commercially available fluorocarbon stationary phases and no ion-pair reagents in HPLC. One pentafluorophenyl column showed the highest potential for the separation of a larger number of arsenic species when using simple acid-based mobile phases. After modification of the operational parameters in HPLC, the speciation analysis of 13 representative arsenic species: arsenite, arsenate, methylarsonic acid, dimethylarsinic acid, trimethylarsine oxide, tetramethylarsonium, arsenobetaine, arsenocholine, thio-dimethylarsinic acid, oxo-arsenosugar-glycerol, oxo-arsenosugar-phosphate, oxo-arsenosugar-sulfonate, and oxo-arsenosugar-sulfate, was achieved by HPLC-ICP-MS with the column along with a mobile phase of 0.
View Article and Find Full Text PDFA multiple channel-type concentric grid nebulizer (m-CGrid) was developed for realizing efficient online standard addition in inductively coupled plasma optical emission spectrometry (ICP-OES) without premixing of liquids before nebulization. The m-CGrid can nebulize two independent liquids without premixing due to a unique structure, having two independent liquid-flow capillaries inside a single nozzle and a grid screen (over 350 mesh per inch) placed on the hole of the nozzle. The grid acts as both a flow damper and sieve; two liquids are well-mixed with a gas flow in a small space just before the grid screen, and the mixture breaks up into small droplets by passing through the grid.
View Article and Find Full Text PDFA certified reference material (CRM), NMIJ CRM 7203-a, was developed for the elemental analysis of tap water. At least two independent analytical methods were applied to characterize the certified value of each element. The elements certified in the present CRM were as follows: Al, As, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, and Zn.
View Article and Find Full Text PDFThe demand for precious metals has increased in recent years. However, low concentrations of precious metals dissolved in wastewater are yet to be recovered because of high operation costs and technical problems. The unicellular red alga, Galdieria sulphuraria, efficiently absorbs precious metals through biosorption.
View Article and Find Full Text PDFThe demand for rare earth elements has increased dramatically in recent years because of their numerous industrial applications, and considerable research efforts have consequently been directed toward recycling these materials. The accumulation of metals in microorganisms is a low-cost and environmentally friendly method for the recovery of metals present in the environment at low levels. Numerous metals, including rare earth elements, can be readily dissolved in aqueous acid, but the efficiency of metal biosorption is usually decreased under the acidic conditions.
View Article and Find Full Text PDFTime-resolved inductively coupled plasma mass spectrometry (ICP-MS) has attracted much attention for elemental and multiparametric analysis of single cells, instead of a classical bulk analysis of large amount of cells after a dissolution. In the time-resolved measurement, cells are directly introduced into the plasma via nebulizing or micro drop dispensing, and then ion plumes corresponding to single cells are individually detected with a high time resolution. The sensitivity and cell throughput in the measurement strongly depend on the time resolution.
View Article and Find Full Text PDFThe hyphenation of SEC with ICP-MS was successfully applied to RNA quantification. The developed method combines the separation technique for large biomolecules and element selective detection of ICP-MS. The separation of RNA molecules was performed under the SEC condition without additive reagents such as salts to prevent the adhesion of RNA molecules on the column resin.
View Article and Find Full Text PDFTo support skill upgrading in analysis of inorganic constituents of environmental and food samples, the National Metrology Institute of Japan (NMIJ) and the National Food Research Institute (NFRI) have organized a proficiency test (PT) of determination of Mn, Fe, Cu, Zn, As, and Cd in brown-rice flour based on the international standard (ISO/IEC 17043:2010). One hundred and thirty-three sets of reports were assessed by use of the E(n)-number and z-score approaches in accordance with ISO/IEC 17043 and the international harmonized protocol for PT. The PT results and analytical procedures, reported in detail, were reviewed, and possible technical reasons for questionable or unsatisfactory results are discussed.
View Article and Find Full Text PDFTrace elemental analysis of single yeast cells with time-resolved inductively coupled plasma mass spectrometry (ICP-MS) was successfully carried out, where a high efficiency cell introduction system (HECIS) consisting of the high performance concentric nebulizer (HPCN) and a low-volume (15 mL) on-axis spray chamber utilizing a sheath gas flow were used. Cell adsorption to the flow injector and sample tubing was reduced with the addition of a simple 4.3 mmol L(-1) of NaCl solution to the cell suspension and cell flowing liquid, allowing consecutive measurements without fear of significant contamination from previous measurements.
View Article and Find Full Text PDFThe coupling system of capillary gel electrophoresis (CGE) and inductively coupled plasma-mass spectrometry (ICP-MS) was newly developed and successfully applied to the double-stranded (ds) DNA quantification. The developed system combines the separation technique for large biomolecules and element selective detection of ICP-MS. This coupling was achieved by using the modified high performance concentric nebulizer (HPCN) with the PTFE tube (HPCN-PT), which can produce the liquid jet by the flow focusing effect.
View Article and Find Full Text PDFA certified reference material (CRM), NMIJ CRM 7512-a, was developed for the determination of trace elements in milk powder. At least three independent analytical methods were applied to characterize the certified value of each element; all of these analytical methods were based on microwave acid digestions and carried out using different analytical instruments. The certified value was given on a dry-mass basis, where the dry-mass correction factor was obtained by drying the sample at 65°C for 15 to 25 h.
View Article and Find Full Text PDFA certified reference material (CRM) for trace cadmium and other elements in brown rice flour was developed at the National Metrology Institute of Japan (NMIJ). The CRM was provided as a dry powder after drying and frozen pulverization of fresh brown rice obtained from a Japanese domestic market. Characterization of the property value for each element was carried out exclusively by NMIJ with at least two independent analytical methods, including inductively coupled plasma mass spectrometry (ICP-MS), ICP high-resolution mass spectrometry, isotope-dilution ICP-MS, ICP optical emission spectrometry, and graphite-furnace atomic-absorption spectrometry.
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