Journal of Analytical Atomic Spectrometry最新文献

The need for elemental analysis in quality control of food, pharmaceuticals and cosmetics, taking into account human safety, has become an essential requirement for any product destinated for commercialization and targets in particular potentially toxic elements. The main objective is to obtain reliable data on elemental content that enables end-users to make informed decisions and to address problems effectively. To align with the principles of green and sustainable analytical chemistry, recent efforts have focused on incorporating new, low-cost screening and quantitative analytical tools such as total reflection X-ray fluorescence spectrometry (TXRF). This paper provides an overview of recent TXRF applications in the elemental analysis of food, pharmaceuticals, and cosmetic samples. The state-of-the-art procedures for sample preparation with details on the sample type and amount, dilution steps, mixing agents, analysed elements, and addition of internal calibration standards are presented together with analytical parameters such as limits of detection and quantification. The current challenges for applying TXRF to each of these research fields are discussed.

Cisplatin (Pt(NH₃)₂Cl₂) and other platinum-based drugs are widely used medications that treat several different cancers, including, but not limited to, ovarian, testicular, and neck. Here, we investigate the uptake of cisplatin in human glioblastoma U87 cells and its impact on other ions with the use of the micro-PIXE technique. Cells were treated with cisplatin at concentrations of 10, 20, and 100 μM for 24 hours. The micro-PIXE technique allowed the quantification of the elements in the cells and provided the generation of two-dimensional elemental maps with micrometric spatial resolution. By measuring the chlorine and platinum signals, we were able to identify single cells and detect those with higher platinum concentrations, respectively. Furthermore, the analysis of the whole PIXE spectra allowed the identification of an increase in iron in cells treated with 100 μM. This result is consistent with the hypothesis of cisplatin-induced ferroptosis, which was validated by lipid peroxidation using flow cytometry. We conclude that cell uptake of cisplatin is heterogeneous and that high uptake of cisplatin correlates with high Fe accumulation.

Microwave-assisted extraction (MAE) treatments seem to be a promising sample preparation strategy to isolate nanomaterials (NMs) from environmental samples prior to single particle inductively coupled plasma mass (spICP-MS) determination. Nevertheless, because previous studies make use of domestic microwave ovens (DMOs), several shortcomings arise that compromise the analysis such as lack of control of experimental variables, limited operating conditions, and uncontrolled sample heating leading to irreproducibility issues. The goal of this work is to adapt previously developed MAE treatments for soil and air filters with the DMO apparatus to state-of-the-art scientific microwave ovens (SMOs) in order to standardize current analytical protocols for NM characterization. Results show that, by working with an SMO, non-labile metallic NMs (Pt-AuNPs) are quantitively extracted from soil and air filter samples unaltered in 10 min and 6 min, respectively, at 1200 W by using 10 mL of NaOH 0.1 M solution. The use of a SMO system allows improving accuracy (above 10% of the particle recovery), precision (above 5% of the RSD) and sample throughput (above 4-fold) when compared to the DMO ones. According to these findings, MAE seems to be a powerful strategy for routine analysis of non-labile NMs in environmental samples.

Di-uranate is the most important uranium hydrometallurgical product in uranium mining and metallurgy. It is an important raw material in the nuclear industry. Rapid and accurate determination of its uranium content is of great significance for product trading and production process control. At present, it mainly relies on traditional methods, namely ferrous sulfate reduction/potassium dichromate oxidation titration, which involves a complex operation process and lengthy analysis time. Laser induced breakdown spectroscopy (LIBS) is a spectroscopic technique based on atomic emission, which has been proven to be very effective in rapid detection of other elements. However, there are still problems such as severe spectral interference and poor quantitative results of the uranium element. This work explored the feasibility of beam shaping modulation technology in improving the spectral interference level of di-uranate samples, and compared the quantitative performance of uranium between the Gaussian beam and flat-top beam. It was found that, compared to the Gaussian beam, the signal intensity of the flat-top beam has been enhanced, and the degree of spectral interference, signal uncertainty, and quantitative performance have also been improved. The signal strength has increased by 1–2 times, and the signal uncertainty has decreased by about 30%. Spectral peaks with severe overlap can be clearly identified, such as Fe I 480.77 nm and U I 481.09 nm. The determination coefficient (R²), root mean square error (RMSE), and relative standard deviation (RSD) of the quantitative model have been improved from 0.9787, 1.4027, and 1.88% of the Gaussian beam to 0.9857, 0.4828, and 1.48% of the flat-top beam. Besides, by calculating the plasma parameters, it was also found that the difference in plasma parameters between samples of the flat-top beam also decreases, which may be an important reason why beam shaping technology can improve quantitative performance. The results based on flat-top beam LIBS provide a basis for online measurement of uranium in di-uranate samples.

Correction for ‘Development of a multi-isotopic (Pb, Fe, Cu) analytical protocol in gold matrices for ancient coin provenance studies’ by Louise de Palaminy et al., J. Anal. At. Spectrom., 2024, https://doi.org/10.1039/d3ja00312d.

The demand for high-resolution imaging, and high sample throughputs in LA-ICP-MS experiments has led to developing rapid-response ablation cells with low dispersion. These cells can achieve short transient signals called single pulse responses (SPRs), whose width is in the single-digit millisecond range at 1% of the maximum. However, coupled with ICP-Q-MS, recording those short signals poses a problem due to the sequential measurement of selected m/z ratios. If more than one m/z ratio is targeted, the time resolution of quadrupole detection systems is insufficient for accurately determining short SPRs. This work focuses on utilizing rapid response ablation cells for the analysis of multiple elements with quadrupole-based detection systems in the SPR mode. To achieve this, an ArF-excimer laser equipped with a rapid-response ablation chamber is coupled to an ICP-MS with a short settling time of 0.2 ms and below. The two naturally occurring Ag-isotopes were analyzed in the NIST SRM 612 to optimize the dwell times for ideal data acquisition. The data shows that the ratio of the dwell time and the settling time, plays a crucial role. With the optimized parameters, the natural ratio of ¹⁰⁷Ag and ¹⁰⁹Ag within a 10 ms FW0.01M transient signal could be determined. This concept of LA-ICP-MS was then applied for depth profiling analysis of Al-doped SiC, a wide bandgap semiconductor. This procedure acquired depth profiles on 30 different sample locations in approximately 2 minutes with an exceptional depth resolution of 55 nm.

This is the 16th Atomic Spectrometry Update (ASU) to focus on advances in elemental speciation and covers a period of approximately 12 months from January 2023. This ASU review deals with all aspects of the analytical atomic spectrometry speciation methods developed for: the determination of oxidation states; organometallic compounds; coordination compounds; metal and heteroatom-containing biomolecules, including metalloproteins, proteins, peptides and amino acids; and the use of metal-tagging to facilitate detection via atomic spectrometry. As with all ASU reviews the focus of the research reviewed includes those methods that incorporate atomic spectrometry as the measurement technique. However, because speciation analysis is inherently focused on the relationship between the metal(loid) atom and the organic moiety it is bound to, or incorporated within, atomic spectrometry alone cannot be the sole analytical approach of interest. For this reason, molecular detection techniques are also included where they have provided a complementary approach to speciation analysis. The number of publications covered this year has increased since last year but remains relatively low compared to many of the years that this ASU has been published for. However, there is a good breadth of elements covered, over 20 this year, with the most popular elements still being As, Hg and Se whilst Ge and Tc both make their first appearances this year. Another item to note is the decreasing quality of the abstract for many of the papers, with detail on the methodology, key results with data included, conclusions and implications thereof missing. This is likely to lead to fewer researchers reading the article.

In this paper, a fiber laser marking machine was used to pretreat an Al plate, and then a Au nanoparticle (Au NP) solution was dripped on the surface of the pre-treated plate to study the effect of the laser pretreatment assisted-nanoparticle-enhanced laser-induced breakdown spectroscopy technique on the emission and stability of the AlO molecular bands (B²∑⁺ − X²∑, Δν = 0) in the Al plasma. The results showed that laser pretreatment significantly improved the emission and stability of the AlO molecular bands. Therefore, this paper demonstrates the potential of laser pretreatment in improving analytical sensitivity in LIBS.

We investigate the use of single particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOFMS) to measure isotopic ratios within individual sub-micron particles and explore the advantages and limitations of this method. Through the analysis of samarium (Sm) isotopes—¹⁴⁷Sm and ¹⁴⁹Sm—in individual monazite particles, and lead (Pb) isotopes—²⁰⁶Pb and ²⁰⁸Pb—in individual galena particles, we demonstrate that isotope ratios recorded by spICP-TOFMS have precision controlled by Poisson statistics. This precision depends on the signal amount measured per isotope from an individual particle: as particle size increases, more counts of each isotope are detected, and the precision improves. In monazite particles with mass amounts of Sm from 0.04 to 4 fg, recorded isotope-ratio precision (relative standard deviation, RSD) ranged from 43% to 5%. However, the average isotope ratio from a particle population is still accurate; the molar ratio determined for ¹⁴⁹Sm/¹⁴⁷Sm was 0.912, which is within 1% of the expected ratio. Lead isotopic composition varies widely in nature because ²⁰⁶Pb, ²⁰⁷Pb, and ²⁰⁸Pb are radiogenic isotopes that decay from thorium (Th) and uranium (U). In the analysis of lead isotopes from galena particles, we found that the RSD for ²⁰⁸Pb/²⁰⁶Pb ratio ranged from 32% to 2% for particles with 1.4 to 80 fg of Pb. We further explore the use of spICP-TOFMS for radiometric dating of monazite particles. Monazite is used in geochronology for radiometric dating based on ²⁰⁸Pb/²³²Th and ²⁰⁶Pb/²³⁸U ratios. spICP-TOFMS analyses of individual monazite particles that contain only 0.02–80 fg of Th and 0.03–30 fg of U showed radiogenic Pb-isotope signatures and a median age of 550 Ma. We also show that the spread of ages from monazite particles is broader than explainable by Poisson statistics, revealing real variation in age or depletion/enrichment of Pb, Th, and/or U in the particles. Overall, we demonstrate that spICP-TOFMS can be used for accurate isotope-ratio analysis with precisions down to a few percent; however, understanding measurement noise is critical to define the significance of isotope ratios measured from individual particles.

Silver isotopes have been extensively used in environment, archaeology, and economic geology. Nevertheless, accurate analysis of Ag isotope ratios faces challenges caused by the presence of matrix elements (e.g. Zn, Cu, and Pb) in most sulfide samples due to isobaric and polyatomic interferences during multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) routines. Most of these elements, such as Cu and Pb, can be effectively removed after the first column through a tandem column setup. However, the complete removal of Zn from Ag remains a significant unresolved issue, particularly given their common coexistence in sulfide minerals. Combining previous studies and the chemical principle of ion exchange resin, we optimized a two-stage ion exchange procedure by meticulously adjusting solution volumes and the column separation process. A condensed Zn-doped NIST SRM (silver international standard reference material) 978a was tested for AG50W-X8 resin following our modified procedure, resulting in distinct elution curves of Ag and Zn. Subsequently, three sphalerite samples were selected for the optimized two-stage ion exchange procedure, and ICP-MS results of silver elution fractions demonstrated complete separation of Ag and Zn. The whole procedure achieved an Ag yield exceeding 98.1 ± 2.3% (2SD, n = 4). NIST SRM 978a and IAEA-S-1 (an in-house standard) were tested for long-term reproducibility with −0.001 ± 0.030‰ (2SD, n = 25) and 0.054 ± 0.023‰ (2SD, n = 22) of δ¹⁰⁹Ag, respectively, indicating the high accuracy in MC-ICPMS routines. Zn-doped NIST SRM 978a and sphalerite samples were further subjected to the modified procedure, and they exhibited values of 0.004 ± 0.014‰ (2SD, n = 3) and −0.214 ± 0.033‰ (2SD, n = 12), respectively, for δ¹⁰⁹Ag. Moreover, we selected eight sphalerite samples from several hypogene deposits in China and obtained δ¹⁰⁹Ag values from −0.229‰ to 2.227‰, indicating the significant Ag isotopic fractionation between Ag-bearing and Zn-rich minerals in hypogene deposits. In conclusion, this study shows the feasibility of accurately measuring Ag isotopes in Zn-rich samples and reveals their application potential in related Ag-bearing and Zn-rich deposits.