Aerosol Nanoparticles Research Articles

Discoveries in Aerosol Science: Characterization of Nanoparticles Emitted From Metallic Coils in Electronic Cigarettes

Electronic (e-) cigarettes, also known as electronic nicotine delivery systems, are battery-operated devices that are growing in popularity worldwide. Although e-cigarettes are known to be safer than traditional cigarettes, their potential health risks have not been extensively reviewed yet. In this study, aerosol nanoparticles generated from e-cigarette heaters were characterized. Kanthal A1 (iron + chromium + aluminum) coils, without nicotine solution or a wick, were installed in an e-cigarette atomizer. The operating conditions were varied coil resistances (0.1–1.0 Ω), a set applied power (10 W), and a stable duty cycle (50%: 5 s on, 5 s off ). The size distribution and morphology of particles were collected by a scanning mobility particle sizer and evaluated by transmission electron microscopy, respectively. From an applied power of 10 W and a 50% duty cycle, the size and total number concentration (TNC) of particles emitted increased with greater coil resistances. Within these operating conditions, the average TNC of particles generated exhibited a steep decrease during the first 15 minutes of each trial. The TNC of particles decreased over time because surface oxidation (iron oxide layer) prevented further nanoparticle emission. As a result, a used coil may reduce the risk of the metal exposure from e-cigarettes. The results indicate that our designed and tested e-cigarette generation system is useful for future research that aims to investigate the health impacts of metallic particle inhalation on e-cigarette users.

Analytical solutions to validate 3D numerical methods for solving direct ultraviolet photoionization and charge recombination of aerosol nanoparticles with laminar flow in circular ducts

This work analyzes UV photocharging of aerosol particles in a cylindrical duct and develops analytical solutions to particular cases. A three-dimensional (3D) numerical method is also developed in order to be used as an example of validation. These methods consider diffusion, photoionization, recombination, and advection by both a fluid and an electric field in a three-dimensional space. In the first place, governing equations are developed to clarify misleading equations found in a previous literature. These equations are then used in analytical methods to find solutions for these particular cases: diffusion only, electric field only, electric field plus photoionization, and, finally, electric field plus recombination. An analysis of these solutions shows the existence of shock/rarefaction waves in the evolution of charged particles’ concentration inside the duct, a very interesting phenomenon that cannot be captured using zero-dimensional (0D) numerical models or a dimensional analysis. The numerical method of lines is applied to generate an axisymmetrical 3D numerical model that is validated using the analytical solutions. A good agreement between the numerical and analytical solutions was obtained despite the simplicity of the numerical method. The paper also comments on the advantages of using the presented methods for the prediction of concentration values against the use of non-dimensional parameters in 0D models.

Biodegradable CA/CPB electrospun nanofibers for efficient retention of airborne nanoparticles

The increase of the industrialization process brought the growth of pollutant emissions into the atmosphere. At the same time, the demand for advances in aerosol filtration is evolving towards more sustainable technologies. Electrospinning is gaining notoriety, once it enables to produce polymeric nanofibers with different additives and also the obtaining of small pore sizes and fiber diameters; desirable features for air filtration materials. Therefore, this work aims to evaluate the filtration performance of cellulose acetate (CA) nanofibers and cationic surfactant cetylpyridinium bromide (CPB) produced by electrospinning technique for retention of aerosol nanoparticles. The pressure drop and collection efficiency measurements of sodium chloride (NaCl) aerosol particles (diameters from 7 to 300 nm) were performed using Scanning Mobility Particle Sizer (SMPS). The average diameter of the electrospun nanofibers used was 239 nm, ranging from 113 to 398 nm. Experimental results indicated that the nanofibers showed good permeability (10−11 m2) and high-efficiency filtration for aerosol nanoparticles (about 100 %), which can include black carbon (BC) and the new coronavirus. The pressure drop was 1.8 kPa at 1.6 cm s-1, which is similar to reported for some high-efficiency nanofiber filters. In addition, it also retains BC particles present in air, which was about 90 % for 375 nm and about 60 % for the 880 nm wavelength. Finally, this research provided information for future designs of indoor air filters and filter media for facial masks with renewable, non-toxic biodegradable, and potential antibacterial characteristics.

Assessment of urban air pollution related to potential nanoparticle emission from photocatalytic pavements

The main objective was to evaluate whether wearing and weathering of nanofunctionalized photocatalytic pavement in real urban environment can lead to undesirable emission of potentially toxic nanoparticle aerosols in urban air. The photocatalytic material was thoroughly tested before its application for conformity criteria in terms of photocatalytic effectiveness, intrinsic performance and undesired secondary effects, and then applied on a pilot scale in downtown Madrid. The aerosol monitoring on the pilot street before the coating applications as well as on the neighbouring streets during 10 months was used as a benchmark for evaluation of spatial and temporal variations. Analysis of the experimental data did not reveal any statistically significant variations in the aerosol concentrations on the pilot street in comparison with the benchmark. The concentration of Ti-containing particles was assessed by aerosol sampling and yielded values below 10 cm−3 that is more than three orders of magnitude below the toxicological limits. A theoretical model was developed to assess the upper bound of nanoparticle aerosol concentration in air. These findings indicated that photocatalytic pavement materials, which comply with conformity criteria under laboratory tests, can have low impact on the particulate contamination of urban air.

Real-Time Measurement of the Hygroscopic Growth Dynamics of Single Aerosol Nanoparticles with Bloch Surface Wave Microscopy.

The growth in aerosol particles caused by water uptake during increasing ambient relative humidity alters the physical and chemical properties of aerosols, which then affects public health, atmospheric chemistry, and the Earth's climate. The temporal resolution and sensitivity of current techniques are not sufficient to measure the growth dynamics of single aerosol nanoparticles. Additionally, the specific time required for phase transition from solid to aqueous has not been measured. Here, we describe a label-free photonic microscope that uses the Bloch surface waves as the illumination source for imaging and sensing to provide real-time measurements of the hygroscopic growth dynamics of a single aerosol (diameter <100 nm) containing the main components of air pollution. This specific time can be measured for both pure and mixed aerosols, showing that organics will delay the phase transition. This photonic microscope can be extended to investigate physicochemical reactions of various aerosols, and then knowing this specific time will be favorable for understanding the reaction kinetics among single aerosols and the surrounding medium.

Approaches to assess the impact of nanoparticles on the human body

The analysis of the behavior of nanoparticles in aerosols, their aerodynamic peculiarities and interaction with microparticles was made. The features of nanoparticle cumulation in the air of the working area of industrial premises during the working day, as well as during two, or three-shifts working day are studied; the features of the nanoparticles aggregation in aerosol with their subsequent degeneration into microparticles and further sedimentation are examined. The features of the transcutaneous entry of nanoparticles into a human body are considered. It was pointed out that nanoparticles of various sizes can differ in their physicochemical properties, and, correspondingly, their influence on biological systems. Therefore, it is shown that in order to establish the toxicological hazard of nanoparticles, it is necessary to establish the most sensitive system and weight concentrations of nanoparticles, as well as their most dangerous size range, i.e. it is necessary to take into account the dispersion distribution of nanoparticles. It was demonstrated that the solubility of micro- and nanoparticles can be crucial for assessing their influence on the body in case of the body transcutaneous entry or by inhalation. Possible approaches to assessing the intensity of the effect of nanoparticles on the human body are considered. New methodological approaches to assessing the effect of nanoparticles on the human body are proposed. The complexity and features of the regulation of nanoparticles in the air of the working area are described. It has been proposed to take into account the value of the “absorbed dose” while assessing the effect of aerosols containing micro- and nanoparticles.

Approaches to assess the impact of nanoparticles on the human body

The analysis of the behavior of nanoparticles in aerosols, their aerodynamic peculiarities and interaction with microparticles was made. The features of nanoparticle cumulation in the air of the working area of industrial premises during the working day, as well as during two, or three-shifts working day are studied; the features of the nanoparticles aggregation in aerosol with their subsequent degeneration into microparticles and further sedimentation are examined. The features of the transcutaneous entry of nanoparticles into a human body are considered. It was pointed out that nanoparticles of various sizes can differ in their physicochemical properties, and, correspondingly, their influence on biological systems. Therefore, it is shown that in order to establish the toxicological hazard of nanoparticles, it is necessary to establish the most sensitive system and weight concentrations of nanoparticles, as well as their most dangerous size range, i.e. it is necessary to take into account the dispersion distribution of nanoparticles. It was demonstrated that the solubility of micro- and nanoparticles can be crucial for assessing their influence on the body in case of the body transcutaneous entry or by inhalation. Possible approaches to assessing the intensity of the effect of nanoparticles on the human body are considered. New methodological approaches to assessing the effect of nanoparticles on the human body are proposed. The complexity and features of the regulation of nanoparticles in the air of the working area are described. It has been proposed to take into account the value of the “absorbed dose” while assessing the effect of aerosols containing micro- and nanoparticles.

Real-time monitoring of cellular oxidative stress during aerosol sampling: a proof of concept study

The Portable In Vitro Exposure Cassette (PIVEC) was developed for on-site air quality testing using lung cells. Here, we describe the incorporation of a sensor within the PIVEC for real time monitoring of cellular oxidative stress during exposure to contaminated air. An electrochemical, enzymatic biosensor based on cytochrome c (cyt c) was selected to measure reactive oxygen species (ROS), including hydrogen peroxide and super oxides, due to the stability of signal over time. Human A549 lung cells were grown at the air–liquid interface and exposed within the PIVEC to dry 40 nm copper nanoparticle aerosols for 10 minutes. The generation of ROS compounds was measured during exposure and post-exposure for one hour using the biosensor and compared to intracellular ROS determined using the 2′,7′-dichlorodihydrofluoroscein diacetate (DCFH-DA) assay. A similar increase in oxidative stress upon aerosol exposure was measured using both the cyt c biosensor and DCFH-DA assay. The incorporation of a biosensor within the PIVEC is a unique, first-of-its-kind system designed to monitor the real-time effect of aerosols.

Quantitative biokinetics over a 28\u2009day period of freshly generated, pristine, 20\u2009nm silver nanoparticle aerosols in healthy adult rats after a single 1\xbd-hour inhalation exposure

BackgroundThere is a steadily increasing quantity of silver nanoparticles (AgNP) produced for numerous industrial, medicinal and private purposes, leading to an increased risk of inhalation exposure for both professionals and consumers. Particle inhalation can result in inflammatory and allergic responses, and there are concerns about other negative health effects from either acute or chronic low-dose exposure.ResultsTo study the fate of inhaled AgNP, healthy adult rats were exposed to 1½-hour intra-tracheal inhalations of pristine 105Ag-radiolabeled, 20 nm AgNP aerosols (with mean doses across all rats of each exposure group of deposited NP-mass and NP-number being 13.5 ± 3.6 μg, 7.9 ± 3.2•1011, respectively). At five time-points (0.75 h, 4 h, 24 h, 7d, 28d) post-exposure (p.e.), a complete balance of the [105Ag]AgNP fate and its degradation products were quantified in organs, tissues, carcass, lavage and body fluids, including excretions.Rapid dissolution of [105Ag]Ag-ions from the [105Ag]AgNP surface was apparent together with both fast particulate airway clearance and long-term particulate clearance from the alveolar region to the larynx. The results are compatible with evidence from the literature that the released [105Ag]Ag-ions precipitate rapidly to low-solubility [105Ag]Ag-salts in the ion-rich epithelial lining lung fluid (ELF) and blood. Based on the existing literature, the degradation products rapidly translocate across the air-blood-barrier (ABB) into the blood and are eliminated via the liver and gall-bladder into the small intestine for fecal excretion. The pathway of [105Ag]Ag-salt precipitates was compatible with auxiliary biokinetics studies at 24 h and 7 days after either intravenous injection or intratracheal or oral instillation of [110mAg]AgNO3 solutions in sentinel groups of rats. However, dissolution of [105Ag]Ag-ions appeared not to be complete after a few hours or days but continued over two weeks p.e. This was due to the additional formation of salt layers on the [105Ag]AgNP surface that mediate and prolonge the dissolution process. The concurrent clearance of persistent cores of [105Ag]AgNP and [105Ag]Ag-salt precipitates results in the elimination of a fraction > 0.8 (per ILD) after one week, each particulate Ag-species accounting for about half of this. After 28 days p.e. the cleared fraction rises marginally to 0.94 while 2/3 of the remaining [105Ag]AgNP are retained in the lungs and 1/3 in secondary organs and tissues with an unknown partition of the Ag species involved. However, making use of our previous biokinetics studies of poorly soluble [195Au]AuNP of the same size and under identical experimental and exposure conditions (Kreyling et al., ACS Nano 2018), the kinetics of the ABB-translocation of [105Ag]Ag-salt precipitates was estimated to reach a fractional maximum of 0.12 at day 3 p.e. and became undetectable 16 days p.e. Hence, persistent cores of [105Ag]AgNP were cleared throughout the study period. Urinary [105Ag]Ag excretion is minimal, finally accumulating to 0.016.ConclusionThe biokinetics of inhaled [105Ag]AgNP is relatively complex since the dissolving [105Ag]Ag-ions (a) form salt layers on the [105Ag]AgNP surface which retard dissolution and (b) the [105Ag]Ag-ions released from the [105Ag]AgNP surface form poorly-soluble precipitates of [105Ag]Ag-salts in ELF. Therefore, hardly any [105Ag]Ag-ion clearance occurs from the lungs but instead [105Ag]AgNP and nano-sized precipitated [105Ag]Ag-salt are cleared via the larynx into GIT and, in addition, via blood, liver, gall bladder into GIT with one common excretional pathway via feces out of the body.

Aerosolization of colloidal nanoparticles by a residual-free atomizer

A new residual-free atomizer was designed to transfer colloidal nanoparticles measuring less than 100 nm into aerosol phase. Miniaturization of droplet size distribution successfully reduced backgr...

A parallelized tool to calculate the electrical mobility of charged aerosol nanoparticles and ions in the gas phase

Electrical Mobility is a transport property that describes a particle behavior in the gas phase. When dealing with the free molecular regime, ascertaining the shape of a nanoparticle or an ion directly from measurements of mobility becomes quite difficult as the particle no longer can be assumed to have spherical shape. Here we propose an efficient parallelized tool, IMoS, that makes use of all-atom models to calculate the mobility of nanoparticles in a variety of gases. The program allows for different types of calculations that range from the efficient Projection Approximation (PA) algorithm to the 4-6-12 Lennard-Jones potential Trajectory Method. It also includes a diffuse inelastic simulation that achieves Millikan's predicted 1.36 value over PA. When compared to experimental results, the error of the most efficient calculations is shown to be approximately 2–4% on average.

Physicochemical and toxicological characteristics of nanoparticles in aerosols in southern Thailand during recent haze episodes in lower southeast Asia

Transboundary haze from biomass burning is one of the most important air pollutions in Southeast Asia. The most recent serious haze episode occurred in 2015. Southern Thailand was affected by the haze during September to October when the particulate matter concentration hit a record high. We investigated physical and chemical characteristics of aerosols, including concentration and aerosol size distribution down to sub-micron sizes during haze episodes in 2013 and 2015 and, for reference, an insignificant haze period in 2017. The highest total suspended particulates and PM10 levels in Hat Yai city were 340.1 and 322.5 µg/m3. The mass fractions were nanoparticles (< 100 nm) 3.1%-14.8% and fine particles (< 1 µm) 54.6%-59.1%. Polycyclic aromatic hydrocarbon size distributions in haze periods peaked at 0.75 µm and the concentrations are 2-30 times higher than the normal period. High molecular weight (4-6 ring) PAHs during the haze episode contribute to about 56.7%-88.0% for nanoparticles. The average values of benzo(a)pyrene toxic equivalency quotient were 3.34±2.54ng/m3 in the 2015 haze period but only 0.89±0.17 ng/m3 in 2017. It is clear that particles smaller than 1 µm, were highly toxic. Nanoparticles contributed 19.4%-26.0% of total BaP-TEQ, whereas the mass fraction is 13.1%-14.8%. Thus the nanoparticles were more carcinogenic and can cause greater health effect than larger particles. The fraction of BaP-TEQ for nanoparticles during 2017 non-haze period was nearly the same, while the mass fraction was lower. This indicates that nanoparticles are the significant source of carcinogenic aerosols both during haze and non-haze periods.

What does ergonomics have to do with nanotechnologies? A case study

Despite recent concerns for workers’ health, exposure situations to nanoparticles can occur in numerous workplaces. Understanding how exposures occur considering human work in these transformations remains a crucial issue of nanotechnologies. The objective of this article is to understand exposure situations to nanoparticles, their determinants and the resources to act on them.This understanding was achieved by specific measurement of nanoparticles aerosols, combined with an analysis of work activity (actions performed and physical strain) in a rubber industry. The presentation of real time measurements, associated with the video of work situations, during confrontation interviews becomes a means of making exposing work activities visible, to analyze and transform them from the points of view formulated by the company's stakeholders. In this way, characterized “typical exposure situations” serve to trigger discussions and open up new spaces for debate highlighting how innovation affects work and gives rise to enhanced prevention projects.

Low Concentration Analysis of Silver Nanoparticles in Consumer Spray Products

The lack of regulations regarding the manufacture of nanoparticle-containing products has enabled the release of many consumer products into the market with uncorroborated claims. Silver nanoparticles are commonly used in consumer goods, particularly in medical and household products. This study was designed to evaluate the aerosol exposure of silver nanoparticles from two consumer spray products currently on the market that claim to contain silver nanoparticles for antibacterial purposes. The study relies on our current understanding of various sampling and analytical methods to effectively evaluate aerosolized nanoparticles, particularly at low concentrations. To characterize low-concentration nanoparticles, various sophisticated sampling methods, including a NanoScan scanning mobility particle sizer, an optical particle sizer, an impinger, and diffusion samplers, were utilized to quantify, collect, and analyze the chemical compositions of the aerosolized products. Our results show that while both products aerosolize silver particles when sprayed, the emitted nanoparticles contain a low concentration of silver and vary in size and overall chemical composition. Further investigation of silver nanoparticle commercial spray products is needed to assess exposure risk and inform health professionals, industrial hygienists, and the general public regarding disparities in product marketing claims and nanoparticle aerosol exposure.

Subchronic continuous inhalation exposure to zinc oxide nanoparticles induces pulmonary cell response in mice

ObjectivesWe used mice as an animal model to investigate the entry of ZnO nanoparticles from the ambient air into the lungs and other organs, subsequent changes in Zn levels and the impact on the transcription of Zn homeostasis-related genes in the lungs. MethodsThe mice were exposed to two concentrations of ZnO nanoparticles; lower (6.46 × 104 particles/cm3) and higher (1.93 × 106 particles/cm3), allowed to breathe the nanoparticles in the air for 12 weeks and subjected to necropsy. Characterization of the ZnO nanoparticles was done using transmission electron microscopy (TEM). Energy-dispersive X-ray (EDX) spectroscopy was used to quantify ZnO nanoparticles in the lungs, brain, liver and kidney. The total zinc content in the lungs, brain, liver, kidney, red blood cells and plasma was estimated by inductively coupled plasma mass spectroscopy (ICP-MS). Transcription rate of the genes was evaluated by RealTime PCR. ResultsThe two concentration of ZnO nanoparticles in the ambient air produced two different outcomes. The lower concentration resulted in significant increases in Zn content of the liver while the higher concentration significantly increased Zn in the lungs (p < 0.05). Additionally, at the lower concentration, Zn content was found to be lower in brain tissue (p < 0.05). Using TEM/EDX we detected ZnO nanoparticles inside the cells in the lungs, kidney and liver. Inhaling ZnO NP at the higher concentration increased the levels of mRNA of the following genes in the lungs: Mt2 (2.56 fold), Slc30a1 (1.52 fold) and Slc30a5 (2.34 fold). At the lower ZnO nanoparticle concentration, only Slc30a7 mRNA levels in the lungs were up (1.74 fold). Thus the two air concentrations of ZnO nanoparticles produced distinct effects on the expression of the Zn-homeostasis related genes. ConclusionUntil adverse health effects of ZnO nanoparticles deposited in organs such as lungs are further investigated and/or ruled out, the exposure to ZnO nanoparticles in aerosols should be avoided or minimised.

Comparison of Thermal and Electrical Sintering of Aerosol Silver Nanoparticles in Process of Aerosol Jet Printing

This article presents a study and comparison of two sintering processes of aerosol nanoparticles in process of aerosol jet printing. Silver lines were deposited on glass and plastic substrates. Then obtained lines were sintered in two ways, specifically, thermal and electric methods. As a result of experiments, it was found that during the deposition process, the width of printed lines, with the same printing parameters, is in the range from 92.3 to 110.4 μm and the height from 1.1 to 1.4 μm. The resistivity of lines on the glass substrate, sintered in two ways, is approximately 12 μΩ·cm. While the resistivity of the lines on the plastic substrate, sintered by electric and thermal methods, is 11.1 and 17.2 μΩ·cm, respectively. Thus, electrical sintering allows one to achieve a smaller (by a factor of 1.5) electrical resistivity of lines on a plastic substrate than thermal sintering, which makes it possible to obtain conductive flexible structures with better characteristics.

Mode of silver clearance following 28-day inhalation exposure to silver nanoparticles determined from lung burden assessment including post-exposure observation periods.

Recently revised OECD inhalation toxicity testing guidelines require measurements of lung burden immediately after and for periods following exposure for nanomaterials. Lung burden is a function of pulmonary deposition and retention of nanoparticles. Using lung burden studies as per OECD guidelines, it may be possible to assess clearance mechanisms of nanoparticles. In this study, male rats were exposed to silver nanoparticle (AgNP) aerosols (18.1-19.6nm) generated from a spark generator. Exposure groups consisted of (1) control (fresh air), (2) low (31.2 ± 8.5µg/m3), (3) moderate (81.8 ± 11.4µg/m3), and (4) high concentrations (115.6 ± 30.5µg/m3). Rats were exposed for 6-h/day, 5-days/week for 4weeks (28-days) based on the revised OECD test guideline 412. Bronchoalveolar lavage (BAL) fluids were collected on post-exposure observation (PEO)-1 and PEO-7days and analyzed for inflammatory cells and inflammatory biomarkers. The lung burdens of Ag from AgNPs were measured on PEO-1, PEO-7, and PEO-28days to obtain quantitative mass concentrations per lung. Differential counting of blood cells and inflammatory biomarkers in BAL fluid and histopathological evaluation of lung tissue indicated that exposure to the high concentrations of AgNP aerosol induced inflammation at PEO-1, slowly resolved at PEO-7 and completely resolved at PEO-28days. Lung burden measurement suggested that Ag from AgNPs was cleared through two different modes; fast and slow clearance. The fast clearance component was concentration-dependent with half-times ranging from two to four days and clearance rates of 0.35-0.17/day-1 from low to high concentrations. The slow clearance had half-times of 100, 57, and 76days and clearance rates of 0.009, 0.012, and 0.007/day-1 for the high, moderate and low concentration exposure. The exact mechanism of clearance is not known currently. The fast clearance component which was concentration-dependent could be dependent on the dissolution of AgNPs and the slow clearance would be due to slow clearance of the low dissolution AgNPs secondary particles originating from silver ions reacting with biogenic anions. These secondary AgNPs might be cleared by mechanisms other than dissolution such as mucociliary escalation, translocation to the lymphatic system or other organs.

Collection of Metal Aerosol Nanoparticles at High Temperature

The deposition of aerosol nanoparticles in a quartz fibrous filter has been studied at a temperature of 700°C. It has been found that nanoparticles with radii larger than 2 nm formed in air from vapors of heavy refractory metals do not rebound from submicron quarts fibers at nanoaerosol flow velocities through the filter below 100 cm/s. It has been shown that the nanoparticles collected on the filter are not desorbed upon air backwash.

Triboemission of FINE and Ultrafine Aerosol Particles: A New Approach for Measurement and Accurate Quantification

A dynamic model based on mass balance of fine aerosol particles was developed in order to tackle the problem of accurate quantification of mechanically stimulated particle emission (MSPE) from nanofunctionalized and solid lubricating materials. In contrast to the conventional approach, the model accounts for the effect of air turbulization caused by moving parts of the experimental tribological setup on the enhancement of particle deposition velocity. The increase of the velocity of the moving parts results in an increase of the deposition velocity that leads to a significant underestimation of experimentally measured particle emission rates. The developed model was experimentally verified using natural and artificial nanoparticle aerosols. Finally, the new methodology of particle emission rate quantification was employed for the analysis of fine particle emission produced when the solid lubricating materials were tested against a sliding steel surface. The developed method paves the way for defining a standard method of experimental assessment of nanoparticle triboemission enabling the experimental results obtained in various laboratories to be compared. It also bridges the gap between the phenomenological models and experimental measurements.

Ejector-based nanoparticle sampling from pressures down to 20 mbar

The application of standard online instrumentation, such as scanning mobility particle sizer (SMPS), centrifugal particle mass analyzer or aerosol particle mass analyzer (CPMA/APM), and electrical low-pressure impactor (ELPI+) to low-pressure processes is only possible with extensive modification of the devices and extensive calibrations. A low-pressure ejector is a suitable device to transfer aerosol nanoparticles from low-pressure regions to atmospheric pressure and allows the direct use of standard online instrumentation. In this work, a commercial low-pressure ejector is investigated in the pressure range from 20–180 mbar with fully-sintered and size-selected nanoparticles (15–80 nm) in order to extend the application range of online instruments to low-pressure processes and open up a new variety of analysis methods. Results are compared to our previous work which was limited to pressures above 120 mbar. A change in particle size during the measurements for fully-sintered silver particles was not observed. A particle dilution factor between 60–6500 was found. High particle losses in the ejector for large particle sizes are compensated by a lower gas dilution factor.