Search Results (74)

Titanium dioxide (TiO₂) nano- and submicrometric particles’ widespread use in different sectors raised concerns about human and environmental exposure. The validation of analytical methods is essential to ensure reliability in risk assessment studies. In this study, a single-particle inductively coupled plasma mass spectrometry (spICP-MS) method was validated for the detection, quantification, and dimensional characterization of TiO₂ particles in biological tissues. Tissue samples collected after exposure to TiO₂ particles underwent mild acidic digestion using a HNO₃/H₂O₂ mixture to achieve complete matrix decomposition while preserving particle integrity. The resulting digests were analyzed by ICP-MS operated in single-particle mode to quantify and size TiO₂ particles. Method validation was conducted according to ISO/IEC 17025:2017 and included linearity, repeatability, recovery, and detection limit assessments. The limit of detection for TiO₂ particles was 0.04 µg/g, and 55.7 nm was the size the detection limit. Repeatability was within 0.5–11.5% for both TiO₂ mass concentrations and particle size determination. The validated method was applied to tissues from inhalation-exposed subjects, showing TiO₂ levels of 80 ± 20 µg TiO₂/g and particle number concentrations of 5.0 × 10⁵ ± 1.2 × 10⁵ part. TiO₂/mg. Detected TiO₂ particles’ mean diameter ranged from 230 to 330 nm. The developed and validated spICP-MS method provides robust and sensitive quantification of TiO₂ particles in biological matrices, supporting its use in human biomonitoring and exposure assessment studies. Full article

In soils, it is key to not simply determine the behavior of the major elements but also understand the fate of trace and ultra-trace elements that can often have disproportionate effects on these complex systems. Soils, including agricultural soils, constitute a reservoir of nanoparticles and natural colloids of multiple origins. Nonetheless, only limited information is available on the concentrations and fate of nanoparticles in soils, due largely to the difficulty of distinguishing anthropogenically generated particles from the complex soil matrices in which they are found. Bulk measurements are often unable to quantify the key contributions of trace pollutants (i.e., needle in a haystack); however, single particle techniques have recently become available for studying complex agricultural systems, including soils. For example, the characterization of engineered nanoparticles or incidentally generated particulate pollutants within a natural soil or sediment is now possible using techniques such as single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Nonetheless, in order to exploit the single particle techniques, it is first necessary to representatively sample the soils. The approach presented here has been designed to help better understand the impact of incidental and engineered nanoparticles on agricultural soils. In this study, we examine two approaches for extracting colloidal particles (CP) from soils in order to facilitate their characterization by single particle inductively coupled plasma mass spectrometry using a sector field- (SP-ICP-SF-MS) and time-of-flight- (SP-ICP-ToF-MS) based instruments. A novel sampling methodology consisting of an ultrasound-assisted continuous-flow extraction (USCFE) was developed and compared to a commonly used batch extraction procedure. Metal containing colloidal particles (M–CP) were quantified and characterized following their extraction in ultrapure water and tetrasodium pyrophosphate (TSPP). At least five successive extraction cycles of 18 h each were required to optimally extract Si–CP (ca. 6 × 10¹⁵ kg⁻¹) using the batch extraction approach, whereas similarly high numbers of CP could be extracted by USCFE in about 3 h. The combined use of continuous flow, ultrasound and TSPP improved the sampling of colloidal particles and nanoparticles from an agricultural soil. Due to its higher sensitivity, SP-ICP-SF-MS was used to measure the smallest detectable M–CP in the soil extracts. SP-ICP-ToF-MS was used to determine the multi-elemental composition of the extracted colloidal particles. Full article

This study investigates the elemental composition of magnetic nanoparticles (MNPs) in eleven wildland–urban interface (WUI) fire ashes, including one vegetation, six structural, and four vehicle ashes, along with three fire-impacted soil samples. The WUI fire ash samples were collected following the 2020 North Complex (NC) Fire and Sonoma–Lake–Napa unit (LNU) Lightning Complex Fire in California. Efficiency of magnetic separation was confirmed via Time-Domain Nuclear Magnetic Resonance (TD-NMR); the relaxometry showed that the transverse relaxation rate R₂ decreased from 2.02 s⁻¹ before separation to 0.29 s⁻¹ after separation (ΔR₂ = −1.73 s⁻¹; −86%), due to the removal of magnetic particles. The particle number concentrations, size distributions, and elemental compositions (and ratios) of MNPs were determined using single particle-inductively coupled plasma–time-of-flight-mass spectrometry (SP-ICP-TOF-MS). The major types of nanoparticles (NPs) detected in the magnetically separated MNPs were Fe-, Ti-, Cr-, Pb-, Mn-, and Zn-bearing NPs. The iron-bearing NPs accounted for 3.2 to 83.5% of the magnetically separated MNPs, and decreased following the order vegetation ash (77.4%) > soil (63.2–69.9%) > structural (3.2–83.5%) ash. The titanium-bearing NPs accounted for 3.3 to 66.1% of the magnetically separated MNPs, and decreased following the order vehicle (14.1–66.1%) > structural (3.5–36.4%) > vegetation (3.3%) ash. The majority of the detected NPs in the fire ashes occurred in the form of multi-metal (mm) NPs, attributed to the presence of NPs as heteroaggregates and/or due to the sorption of metals on the surfaces of NPs during combustion. However, a notable fraction (3–91%) of the detected NPs occurred as single-metal (sm) NPs, particularly smFe-bearing NPs, which accounted for 48 to 91% of all the Fe-bearing particles in the magnetically separated MNPs. The elemental ratios (e.g., Al/Fe, Ti/Fe, Cr/Fe, and Zn/Fe) in the magnetically separated MNPs from structural and vehicle ashes were higher than those in the soil samples and vegetation ashes, indicating enrichment of metals in magnetically separated NPs from vehicle and structural ashes compared to vegetation ash. Overall, this study demonstrates that the MNPs generated by WUI fire ash are associated with potentially toxic elements (e.g., Cr and Zn), exacerbating the environmental and human health risks of WUI fires. This study also highlights the need for further research into the properties, environmental fate, transport, and interactions of MNPs with biological systems during and following WUI fires. Full article

Single-particle inductively coupled plasma mass spectrometry (spICP-MS) offers the unprecedented advantage of sensitive and selective detection of individual particles based on their constituent elements. It has been applied to the qualitative/quantitative evaluation of nonporous/mesoporous particles ranging from the nanoscale to the microscale and, recently, targeted proteins bound to particles. However, lipid membranes bound to particles have not been explored as potential targets for spICP-MS, despite its analytical potential. To address this, we investigated the applicability of spICP-MS for evaluating the binding states of two different types of lipid membranes (liposomes, i.e., phospholipid bilayer-based spherical vesicles, and nanodiscs comprising a disc-shaped phospholipid bilayer and membrane scaffold protein) to mesoporous silica microspheres (SBA24). The presence of bound liposomes and nanodiscs was confirmed using spICP-MS, which selectively monitored the derived P as a marker element. The presence of bound liposomes was confirmed by confocal laser Raman microscopy. Our findings demonstrate that spICP-MS can be used to qualitatively evaluate the binding states of lipid membranes to mesoporous SiO₂ microspheres. This method offers a new platform for evaluating the effectiveness of particles as carriers of biomolecules (lipid membranes) and provides valuable insights into biomedical research and quality control in related industries. Full article

Illegal logging is a major threat to tropical forests; however, control mechanisms and efforts to combat illegal logging have not effectively curbed fraud in the production chain, highlighting the need for effective methods to verify the geographic origin of timber. This study investigates the application of multi-elemental analysis combined with Principal Component Analysis (PCA) to discriminate the provenance of tropical timber in the Brazilian Legal Amazon. Wood samples of Hymenaea courbaril L. (Jatobá), Handroanthus sp. (Ipê), and Manilkara huberi (Ducke) A. Chevalier. (Maçaranduba) were taken from multiple sites. Elemental concentrations were determined via Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and CA was applied to evaluate geographic differentiation. Significant differences in elemental profiles were found among locations, particularly when using the intermediate disk portions (25% to 75%), and especially the average of all five sampled portions, which proved most effective in geographic discrimination of the trunk. Elements such as Ca, Sr, Cr, Cu, Zn, and B were especially important for spatial discrimination. These findings underscore the forensic potential of multi-elemental wood profiling as a tool to support law enforcement and environmental monitoring by providing scientifically grounded evidence of timber origin. Full article

The use of different nanoparticles (NPs) is increasing in a wide variety of everyday products. Nevertheless, most studies concerning NP risk assessment have evaluated exposure scenarios involving a single kind of NP. A stepwise study distinguishing between the effects resulting from exposure to one kind of NP and those resulting from different co-exposure scenarios to ${\mathrm{Al}}_2{\mathrm{O}}_3$ and ${\mathrm{CeO}}_2$ NPs at concentrations below acute toxicity was conducted with different analytical techniques. As a starting point, WST-1 viability assays were performed to assess whether the chosen exposure concentrations resulted in any acute loss of viability, which would hamper further insight into the cellular response to NP exposure. Then, data on NP dissolution and uptake were obtained via single-particle inductively coupled plasma–mass spectrometry (spICP-MS) and microwave-assisted ICP-MS. Additionally, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was performed to check for differences in the biological response to the exposure scenarios at the single-cell level. It was found that the proposed combined techniques provide insight into changes in biological responses as well as cellular metal contents among the exposure scenarios. In this work, a comprehensive tiered analytical strategy for evaluating the biological responses to challenging exposure scenarios is provided. The results highlight the necessity of selecting situations more closely resembling real life—including concentrations below acute toxicity and potential interactions due to multiple NPs—when estimating potential health risks. These findings thus provide a foundation and an incentive for further research into the complex processes leading to the observed effects. Full article

The aim of this experiment was to investigate the differences in the uptake and accumulation of rare earth elements (REEs) between selected plant species and the substrates used (soil with increased REE content, ash, and smelter waste). Eight plant species were included in the study: common yarrow (Achillea millefolium), false mayweed (Triplerosperum maritimum), tall fescue (Festuca arundinacea), marigold (Tagetes sp.), maize (Zea mays), white mustard (Sinapis alba), red clover (Trifolium pratense L.), and autumn fern (Dryopteris erythrosora). The study focused on the following REE representatives: lanthanum (La), cerium (Ce), europium (Eu), and gadolinium (Gd). Plant samples, divided into roots and shoots, were analyzed by ICP-MS. The obtained REE concentrations in plant tissues ranged from 9 to 697 µg kg⁻¹ (La), 10 to 1518 µg kg⁻¹ (Ce), 9 to 69 µg kg⁻¹ (Eu), and 9 to 189 µg kg⁻¹ (Gd). To determine the ability of plants to phytoextract REE, two factors were calculated: the translocation factor (TF) and the bioconcentration factor (BCF). The highest TF value was obtained for D. erythrosora growing on a substrate consisting of soil with increased REE content (Gd, TF = 4.03). Additionally, TF > 1 was obtained for all REEs in T. pratense L. In the experiment, the BCF was lower than 1 for all the plants tested. The study provided insight into the varying ability of plants to accumulate REEs, depending on both the plant species and the chemical properties of the substrate. Full article

Cancer ranks among the top causes of illness and death globally. Nanotechnology holds considerable promise for enhancing the effectiveness of therapeutic and diagnostic approaches in cancer treatment. Our study presents a promising strategy for applying thiocompound nanomedicine in cancer therapy. Our first study aimed to investigate the biological properties of a new compound thiodiosgenin (TDG)—a new derivative of diosgenin—a natural compound with known antioxidant and anticancer properties. Our current second study aimed to compare the therapeutic efficacy of a new diosgenin—functionalized gold nanoparticles—with its precursor on prostate cancer (DU-145) cell lines. Moreover, the safety of the new thio-derivative and new conjugates was tested against the human epithelial line PNT-2. New advanced analytical techniques were developed for the characterization of nanomaterials using methods such as SP-ICP-MS, UV-Vis, TEM, NMR, FT-IR ELS, and TGA. Our synthetic approach was based, on the one hand, on the ligand exchange of citrates to thiodiosgenin (TDG) on gold nanoparticles, and on the other hand, on the attachment of DG through an ester bond to the linker, which was 3-mercaptopropionic acid (MPA) on gold nanoparticles. Initial in vitro studies indicate that TDG shows greater cytotoxic effects on cancer cells but poses risks to normal prostate epithelial cells (PNT-2). It was demonstrated that all the conjugates produced exhibited significant cytotoxic effects against cancer cells while being less harmful to normal prostate epithelial cells (PNT-2) compared to TDG itself. All the obtained conjugates showed antitumor properties; however, for targeted transport, the system referred to as AuNPs-MPAm1-DG is promising, due to the size of the nanoparticles of 53 nm, zeta potential of -30 mV, and loading content of 27.6%. New methods for synthesizing conjugates with diosgenin were developed and optimized for medical applications. Advanced new analytical methodologies were developed to characterize new conjugates, particularly the use of SP-ICP-MS, to solve existing differences in the shape and morphology of the surface of new conjugates. Full article

With the rapid industrialization and urbanization of coastal areas, marine pollution (such as heavy metals) is increasingly contaminating the environment, posing significant public health risks. Eastern Guangdong, a key aquaculture and fisheries hub in China, has a growing market for aquatic products. Heavy metals persist in the environment and are difficult to degrade and bioaccumulate in marine organisms through the food web, presenting carcinogenic and mutagenic risks to humans, as top predators. This study analyzed 10 key species commonly consumed by residents of eastern Guangdong (bivalves, crustaceans, and fish), measuring the concentrations of six heavy metals (As, Cd, Cr, Cu, Ni, Pb) using inductively coupled plasma mass spectrometry (ICP-MS). Pollution levels were assessed using the pollution index (Pi), and dietary exposure risks were evaluated via the target hazard quotient (THQ) for different age groups. Results showed that Pi values for all metals were within normal background levels, but bivalves had a high capacity for Cd accumulation, with pollution severity ranking as bivalves > crustaceans > fish. The THQ values for both adults and teenagers were <1 across all samples, indicating no risk to the health of residents. However, the TTHQ for Sanguinolaria sp. exceeded 1, indicating potential health risks. This study highlights the health risks of consuming heavy metal-contaminated aquatic products, particularly bivalves. Reducing the consumption of these high-metal species could help lower dietary exposure and associated risks. Our findings provide essential data for the quality assessment of aquatic products and offer dietary recommendations for residents in eastern Guangdong. Full article

Copper oxide nanoparticles (CuO-NPs) are widely used for their catalytic properties, conductive capacity, and innovations in the fields of superconductors, alloys, and solar energy sensors. To better understand the impact of water chemistry on the stability of CuO nanoparticles, a series of measurements were carried out on nanoparticles suspended in pure water, natural water, and water enriched with natural organic matter fulvic acid (FA). ICP-MS characterization in single-particle mode (SP-ICP-MS) was performed to determine the stability or transformation of nanoparticles in contrasting water conditions. We first observed that particle sedimentation was very fast in pure Milli-Q water. The addition of FA favored the dissolution of CuO-NPs with an increase in the dissolved copper concentration, for both Milli-Q water and natural water. The presence of FA also reduced the size of CuO-NPs (i.e., less aggregation) measured in natural water. By comparing signals of single particles, FA decreased nanoparticle numbers as well, confirming the increase in dissolution of CuO-NPs over time. The transformation products of CuO-NPs are important in the ecological context since the uptake and toxicity of parent nanoparticles differ from those of the chemical species in solution. Further considerations are needed on the fate of released NPs to better assess their exposure pathways to aquatic organisms and potential environmental risks. Full article

Environmental contamination by potentially toxic elements (PTEs) poses a significant challenge, particularly in the metropolitan regions of developing countries. This issue arises from the high levels of pollution driven by industrial growth and the increased traffic from fossil fuel-powered vehicles. Even after the wastewater treatment in treatment plants, PTEs often persist, posing risks to stream structure and function. This form of pollution is persistent, long-term, and irreversible, presenting a significant challenge in terms of freshwater conservation. This study aimed to assess the water quality and PTE concentrations in urban streams in Santo André, SP, Brazil, to identify the PTEs relevant to stream pollution. We analyzed the water quality in seven catchments in the Santo André municipality, in the metropolitan region of São Paulo, Brazil. The samples were collected during the dry (2021) and rainy periods (2022), and the concentrations of potentially toxic elements (PTEs) were analyzed via inductively coupled plasma–mass spectrometry (ICP-MS). The results showed elevated electrical conductivity (429 ± 211 μS·cm) and low dissolved oxygen concentrations in the streams (2.3 ± 0.95 μg·L), indicating potential problems such as eutrophication and toxicity to aquatic organisms. PTE concentrations, particularly those of Mn (30.8 ± 22.3 μg·L), Fe (91.1 ± 72.1 μg·L), and Zn (38.1 ± 28.7 μg·L), were among the highest concentrations. Seasonal variations affected the PTE concentrations, with Cr and Fe predominating during the dry season and Zn increasing during the rainy season. Associations were found between the PTE concentrations and the water pH, indicating the importance of continuous monitoring and remediation efforts. Full article

Silver nanoparticles (AgNPs), widely used in various fields of technology as an antimicrobial agent, represent a new type of environmental pollutant. Through various routes, AgNPs might penetrate into agricultural crops and foodstuffs. It is important to know if AgNPs contained in food persist in digested food and are therefore available for entering the inner organs of the consumer’s body. Using the technique of single-particle ICP-MS, we analysed the changes in the number and size distribution of AgNPs added to a sample of bread submitted to in vitro simulated gastrointestinal digestion. The majority of silver, in terms of mass, was transformed from the state of particles to the dissolved state during bread digestion, but the number of particles was reduced by 25% only. The most abundant particle size was reduced from 60 nm to 49 nm. Hence, a substantial part of transformed nanoparticles is still present in food digestate. This means that AgNPs consumed together with food can theoretically enter the inner cells of human body. Full article

Alzheimer’s disease (AD) is a prevalent neurodegenerative disorder characterized by cognitive decline and neuropathological hallmarks, including β-amyloid (Aβ) plaques, Tau tangles, synaptic dysfunction and neurodegeneration. Emerging evidence suggests that abnormal iron (Fe) metabolism plays a role in AD pathogenesis, but the precise spatial distribution of the Fe and its transporters, such as ferroportin (FPN), within affected brain regions remains poorly understood. This study investigates the distribution of Fe and FPN in the CA1 region of the human hippocampus in AD patients with a micrometer lateral resolution using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). For this purpose, we visualized and quantified Fe and FPN in three separated CA1 layers: stratum molecular–radial (SMR), stratum pyramidal (SP) and stratum oriens (SO). Additionally, chromogenic immunohistochemistry was used to examine the distribution and colocalization with Tau and Aβ proteins. The results show that Fe accumulation was significantly higher in AD brains, particularly in SMR and SO. However, FPN did not present significantly changes in AD, although it showed a non-uniform distribution across CA1 layers, with elevated levels in SP and SO. Interestingly, minimal overlap was observed between Fe and FPN signals, and none between Fe and areas rich in neurofibrillary tangles (NFTs) or neuritic plaques (NP). In conclusion, the lack of correlation between Fe and FPN signals suggests complex regulatory mechanisms in AD Fe metabolism and deposition. These findings highlight the complexity of Fe dysregulation in AD and its potential role in disease progression. Full article

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 (SiO₂) particles is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO₂ microspheres with a nominal diameter of 5.0 µm or smaller was investigated. Particle sizes of these microspheres were measured using both spICP-MS based on a conventional calibration approach using an ion standard solution and scanning electron microscopy as a reference technique, and the results were compared. The particle size distributions obtained using both techniques were in agreement within analytical uncertainty. The applicability of this technique to the detection of metal-containing protein-binding mesoporous SiO₂ microspheres was also investigated. Bound iron (Fe)-containing proteins (i.e., lactoferrin and transferrin) of mesoporous SiO₂ microspheres were detected using Fe as a presence marker for the proteins. Thus, spICP-MS is applicable to the particle size measurement of large-sized and non-porous/mesoporous SiO₂ microspheres. It has considerable potential for element-based detection and qualification of bound proteins of mesoporous SiO₂ microspheres in a variety of applications. Full article

To clarify potential trans-oceanic connectivity and variation in the natal origin of albacore tuna (Thunnus alalunga) from the southwest Indian Ocean (SWI) and the southeast Atlantic (SA), lifetime otolith elemental signatures were assessed from 46 adults sampled from Reunion Island, and 26 juveniles(group 2+) sampled from two locations along the Atlantic coast of South Africa. LA-ICP-MS analysis was used to assess the multi-elemental composition in B, Ba, Mg, P, Sr, and Zn along the otolith edge (chemical signatures of the capture area), but also near the otolith primordium (spawning origin) and in an area located at 1400–1600 µm from it (nursery origin). Two groups of distinct near-primordium multi-elemental signatures, denoting potentially discrete spawning origins (SpO), were identified using hierarchical clustering. Each of the two SpO was found to contribute to the albacore stocks from all the areas sampled, suggesting a common spawning origin in some fish from the SWI and from the SA, and complex migrations between the two oceans. Three potentially discrete primary nursery sites were identified, each contributing to SA juvenile and SWI adult capture sites differently. The timing for the trans-oceanic movements observed for each albacore capture zone and its implications for local stock management are discussed. Full article