A Sensitive Single Particle-ICP-MS Method for CeO2 Nanoparticles Analysis in Soil during Aging Process.

Uptake, translocation, size characterization and localization of cerium oxide nanoparticles in radish (Raphanus sativus L.)

Tracing isotopically labeled selenium nanoparticles in plants via single-particle ICP-mass spectrometry

Use of single particle inductively coupled plasma mass spectrometry for understanding the formation of bimetallic nanoparticles

To investigate effects of engineered nanoparticles (ENPs) at environmentally relevant concentrations to aquatic microbial communities, TiO2 at 700 µg/L and ZnO at 70 µg/L were spiked to river water samples either separately or combined. Compared to controls where no ENPs were added, the addition of TiO2 ENPs alone at the tested concentration had no statistically significant effect on both the bacterial and eukaryotic communities. The presence of added ENPs: ZnO or ZnO + TiO2 led to significant shift of the microbial community structure and genus distribution. This shift was more obvious for the bacteria than the eukaryotes. Based on results from single particle – inductively coupled plasma – mass spectrometry (SP-ICP-MS), all ENPs aggregated rapidly in water and resulted in much larger particles sizes than the original counterparts. “Dissolved” (including particles smaller than the size detection limits and dissolved ions) concentrations of Ti and Zn increased, too in treatment groups vs. the controls.

BackgroundSafety assessment of nanoparticles (NPs) requires techniques that are suitable to quantify tissue and cellular uptake of NPs. The most commonly applied techniques for this purpose are based on inductively coupled plasma mass spectrometry (ICP-MS). Here we apply and compare three different ICP-MS methods to investigate the cellular uptake of TiO2 (diameter 7 or 20 nm, respectively) and Ag (diameter 50 or 75 nm, respectively) NPs into differentiated mouse neuroblastoma cells (Neuro-2a cells). Cells were incubated with different amounts of the NPs. Thereafter they were either directly analyzed by laser ablation ICP-MS (LA-ICP-MS) or were lysed and lysates were analyzed by ICP-MS and by single particle ICP-MS (SP-ICP-MS).ResultsAll techniques confirmed that smaller particles were taken up to a higher extent when values were converted in an NP number-based dose metric. In contrast to ICP-MS and LA-ICP-MS, this measure is already directly provided through SP-ICP-MS. Analysis of NP size distribution in cell lysates by SP-ICP-MS indicates the formation of NP agglomerates inside cells. LA-ICP-MS imaging shows that some of the 75 nm Ag NPs seemed to be adsorbed onto the cell membranes and were not penetrating into the cells, while most of the 50 nm Ag NPs were internalized. LA-ICP-MS confirms high cell-to-cell variability for NP uptake.ConclusionsBased on our data we propose to combine different ICP-MS techniques in order to reliably determine the average NP mass and number concentrations, NP sizes and size distribution patterns as well as cell-to-cell variations in NP uptake and intracellular localization.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-016-0203-z) contains supplementary material, which is available to authorized users.

Dissolved metal ion removal by online hollow fiber ultrafiltration for enhanced size characterization of metal-containing nanoparticles with single-particle ICP-MS

Monitoring TiO2 nanoparticles (NPs) that are released from functional textiles is significant for assessing the potential risk to consumers. However, determining the size distribution of TiO2 NPs is still a challenge due to agglomeration. The present study employed single particle–inductively coupled plasma–mass spectrometry (SP-ICP-MS) to quantify TiO2 NPs released from functional textiles. Through screening dispersants and validating the standard samples, an accurate method for determining the size and number of TiO2 NPs was developed. The validated procedure was successfully used to determine the release of TiO2 NPs from yarn in sweat and water media throughout the day. The result revealed that the yarn decorated with TiO2 NPs released approximately the same particle size distribution from 60 to 260 nm in both media. The released particle concentration was 0.094 µg/mL with a mean size of 136 nm in water and a particle concentration of 0.120 µg/mL with a mean size of 133 nm in sweat. Additionally, based upon transmission electron microscopy, anatase TiO2 NPs were identified. It is expected that this work is significant in the evaluation of the toxicological effects of multifunctional textiles modified by TiO2 NPs on human health.

Enzymatic hydrolysis as a sample pre-treatment for titanium dioxide nanoparticles assessment in surimi (crab sticks) by single particle ICP-MS

Addressing the complexity of water chemistry in environmental fate modeling for engineered nanoparticles

Isotopic labeling of nanoparticles for the evaluation of their environmental fate in mesocosm experiments

The toxicity of engineered nanoparticles (ENPs) on bacteria has aroused much interest. However, few studies have focused on the effects of low-level ENPs on bacterial group behaviors that are regulated by quorum sensing (QS). Herein, we investigated the effects of nine ENPs (Ag, Fe, ZnO, TiO2, SiO2, Fe2O3, single-wall carbon nanotubes (SWCNTs), graphene oxide (GO), and C60) on QS in Pseudomonas aeruginosa PAOl. An ENP concentration of 100μgL-1 did not impair bacterial growth. However, concentrations of 100μgL-1 of Ag and GO ENPs induced significant increases in 3OC12-HSL in the culture and significantly promoted protease production and biofilm formation of PAO1. C4-HSL synthase and its transcription factors were less sensitive to 100μgL-1 Ag and GO ENPs compared with 3OC12-HSL. Fe ENPs induced a significant increase in the 3OC12-HSL concentration, similar to Ag and GO ENPs. However, Fe ENPs did not induce any significant increase in protease production or biofilm formation. Different size distributions, chemical compositions, and aggregation states of the ENPs had different effects on bacterial QS. These whole circuit indicators could clarify the effects of ENPs on bacterial QS. This study furthers our understanding of the effects of low-level ENPs on bacterial social behaviors.

Redox-active cerium dioxide nanoparticles for mitigating anthracene contamination: Promising solution to polycyclic aromatic hydrocarbon remediation in stormwater-affected soils

The increasing use of titanium dioxide nanoparticles in daily use consumer products such as cosmetics, personal care products, food additives, and even medicine has led to growing concerns regarding human safety. It would be ideal to track exposure to this emerging nanopollutant, for example through bioassays, however, so far nanoparticle assessment in biological matrices such as urine remainschallenging. The lack of data is mainly due to the limitations of the current metrology, but also to the low expected concentration in human samples. In this study, a quantification method for titanium dioxide nanoparticles in urine has been developed and validated following the ISO/CEI 17025:2017 guidelines. The detection limit for titanium dioxide nanoparticle mass concentration by single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was 0.05ngmL-1. The particle size limit was determined using three different approaches, with the highest calculated limit value approaching 50nm. Repeatability and reproducibility of 14% and 18% respectively were achieved for particle mass concentration, and 6% for both parameters for particle size determination. Method trueness and recovery were 98% and 84%, respectively.

Hydrophobicity of biofilm coatings influences the transport dynamics of polystyrene nanoparticles in biofilm-coated sand

Copper oxide and hydroxide nanoparticles (Cu-NPs) are components of some commercial pesticides. When these Cu-NPs dissolve in the environment, their size distribution, efficacy, and toxicity are altered. Since acute toxicity screens typically involve pristine NPs, quantification of the transformation of their size distribution in edible leaf vegetables is necessary for accurate consumer risk assessment. Single particle ICP-MS was used to investigate the persistence of three forms of Cu-NPs following foliar application to live lettuce (Lactuca sativa): CuO NP, Cu(OH)2 NP, and Kocide 3000®. A methanol-based digestion method was used to minimize Cu-NP dissolution during extraction from the leaf tissues. After dosing, the NPs associated with the leaf tissues were characterized over a 9-day period to monitor persistence. Nanoparticle counts and total copper mass concentrations remained constant, though the particle size distributions shifted down over time. Washing the leaves in tap water resulted in removal of total copper while the number of Cu-NPs remaining depended on the form applied. This work indicates that washing of lettuce preferentially removed dissolved Cu over Cu-NPs, and that the amount of residual Cu-NPs remaining is low when applied at the recommended rates for Kocide 3000®.