A High-Performance Aerosol Concentrator for Biological Agent Detection (2025)

Automatic, microprocessor based device, suited for measurement and classification of inhalable airborne particles

A High-Volume Sampler for the Determination of Particle Size Distributions in Ambient Air

Journal of the Air Pollution Control Association, 1976

A system for the sampling of inhalable airborne particles

Environmental Pollution, 1995

This paper describes an instrument developed for the semi-continuous measurement of aerosol mass and its classtj?cation into three classes. These classes have been chosen to evaluate the health hazards caused by inhalable particles. The instrument takes samples through three probes, each providing dtjerent cut-of points (-15 pm, -4 pm, -2 pm) and collects airborne particles on circular membrane filters. The increase in weight is measured by the beta-ray attenuation method.

Performance of High Flow Rate Samplers for Respirable Particle Collection

Annals of Occupational Hygiene, 2010

The American Conference of Governmental Industrial hygienists (ACGIH) lowered the threshold limit value (TLV) for respirable crystalline silica (RCS) exposure from 0.05 to 0.025 mg m 23 in 2006. For a working environment with an airborne dust concentration near this lowered TLV, the sample collected with current standard respirable aerosol samplers might not provide enough RCS for quantitative analysis. Adopting high flow rate sampling devices for respirable dust containing silica may provide a sufficient amount of RCS to be above the limit of quantification even for samples collected for less than full shift. The performances of three high flow rate respirable samplers (CIP10-R, GK2.69, and FSP10) have been evaluated in this study. Eleven different sizes of monodisperse aerosols of ammonium fluorescein were generated with a vibrating orifice aerosol generator in a calm air chamber in order to determine the sampling efficiency of each sampler. Aluminum oxide particles generated by a fluidized bed aerosol generator were used to test (i) the uniformity of a modified calm air chamber, (ii) the effect of loading on the sampling efficiency, and (iii) the performance of dust collection compared to lower flow rate cyclones in common use in the USA (10-mm nylon and Higgins-Dewell cyclones). The coefficient of variation for eight simultaneous samples in the modified calm air chamber ranged from 1.9 to 6.1% for triplicate measures of three different aerosols. The 50% cutoff size ( 50 d ae ) of the high flow rate samplers operated at the flow rates recommended by manufacturers were determined as 4.7, 4.1, and 4.8 mm for CIP10-R, GK2.69, and FSP10, respectively. The mass concentration ratio of the high flow rate samplers to the low flow rate cyclones decreased with decreasing mass median aerodynamic diameter (MMAD) and high flow rate samplers collected more dust than low flow rate samplers by a range of 2-11 times based on gravimetric analysis. Dust loading inside the high flow rate samplers does not appear to affect the particle separation in either FSP10 or GK2.69. The high flow rate samplers overestimated compared to the International Standards Organization/ Comité Européen de Normalisation/ACGIH respirable convention [up to 40% at large MMAD (27.5 mm)] and could provide overestimated exposure data with the current flow rates. However, both cyclones appeared to be able to provide relatively unbiased assessments of RCS when their flow rates were adjusted.

Particle collection characteristics of a single-stage dichotomous sampler

Environmental Science & Technology, 1978

H The aerosol collection characteristics of a single-stage dichotomous sampler are described. The system provides a cutpoint aerodynamic diameter of 3.6 pm when operated a t 14 L/min with a large particle transport air ratio, f , of 10%. Corresponding to this condition the Stokes number for 50% efficiency, Stk.5, is 0.34. The value of Stk.5 is slightly affected by jet Reynolds number but is a strong function off. As f is increased from 5 to 15%, the value of Stk.5 is reduced from 0.56 to 0.19. Wall losses lor the system are 7.1% at the cutpoint size with 14 L/min and f = 10%. These low losses compare favorably with losses of 10.7% for the system when operated with two stages. Fractional efficiency curves for both the singleand two-stage units have steeper slopes than the American

High-performance aerosol sampler with liquid phase recirculation and pre-concentration of particles

Bulletin of Russian State Medical University, 2018

Testing the surrounding environment for the presence of biogenic aerosols is crucial in ensuring its safety for the population. It is often necessary to collect aerosol samples from large areas in short time, which demands excellent particle collection efficiency, a sufficient incoming air flow rate and a capacity to maintain the viability of the collected samples. Below we present the aerosol sampler with a high volumetric flow rate based on a two-stage particle concentration algorithm and consisting of a virtual impactor and a cyclone concentrator with a recirculating liquid phase. We provide all necessary calculations and an algorithm for modeling impactor parameters. The sampler was tested using dry and liquid formulations dispersed into the particles of 0.5 to 5 μm in diameter. We demonstrate that at volumetric flow rates over 4,000 l/min efficiency of particle collection into the liquid phase at a volume of 10 ml makes over 20% of the total aerosol mass and at volumetric flow ...

A passive sampler for airborne coarse particles

Journal of Aerosol Science, 2006

The personal aeroallergen sampler (PAAS) with a structure resembling a gimbal to enable a particle collection surface continuously directed upward regardless of inclination of the sampler was developed. To evaluate the particle size-dependent collection characteristics by the PAAS, the particle size distributions obtained by the PAAS were compared with those by an existing reference active sampler for sampling durations of 5 h to 6 days. The results showed good correlations between the two methods, suggesting usability of the PAAS for long-term personal monitoring of airborne coarse particles such as aeroallergens. The effective particle deposition velocities experimentally obtained for the personal samplings by the PAAS were 0.17, 0.35, 0.66 and 1.6 cm s −1 for particles with projected area diameters of 10-20, 20-30, 30-50 and 50-100 m, respectively. Unlike existing active samplers, the PAAS is convenient for personal air sampling because of simplicity of handling. It can be easily used for epidemiological studies to investigate relationships between aeroallergen exposures and allergic airway diseases. ᭧

Design and Evaluation of a Portable Dilution Sampling System for Measuring Fine Particle Emissions

Aerosol Science and Technology, 2005

Novel Impactor and Microsphere‐Based Assay Used to Measure Containment of Aerosols Generated in a Flow Cytometer Cell Sorter

Cytometry Part A, 2018

Today's state-of-the-art cell sorting flow cytometers are equipped with aerosol containment systems designed to evacuate aerosols from the sort chamber during a sort. This biosafety device is especially important when the sort operator is sorting infectious or potentially infections samples. Hence, it is critical to evaluate the performance for this system in normal operation and in "failure" mode to determine the efficacy of containment. In the past decade, the most popular published method for evaluating containment has been the Glo-Germ bead procedure. These highly fluorescent and multisize particles can easily be detected on a microscope slide and enumerated using a fluorescent microscope. Collecting particles on this slide is accomplished using an Aerotech impactor. This sampler collects potentially escaping aerosols from the sort chamber before enumerating any particles. Although the Glo-Germ procedure has been adopted by many labs, there are several drawbacks with the procedure that have limited its adoption by cell sorter laboratories: The Aerotech impactor is a reusable device that requires rigorous cleaning between measurements. The surface area of the collection slide is large and difficult to scan on a fluorescence microscope. These beads produce a wide variation in sizes resulting in inconsistency in flow rates. Here, we describe a novel and replacement method utilizing a Cyclex-d impactor and Dragon Green beads. This method was compared for sensitivity of detection of escaped aerosols with a published method for aerosol detection which utilizes a UV-APS aerodynamic particle sizer and a UV-excitable dye. One of the advantages of the Cyclex-d system is the narrow-defined field of collection as compared to the standard Glo-Germ bead procedure, this means a smaller sampling area is used in the Cyclexd impactor as compared to the AeroTech impactor. In addition, the sensitivity of detection was found to be better using the Cyclex-d collection device as compared to the standard Glo-Germ bead procedure.

Performance Characteristics of the Aerosol Collectors of the Autonomous Pathogen Detection System (APDS)

Aerosol Science and Technology, 2005

Performance of the original workstation for aerosol tests under controlled conditions

Bulletin of Russian State Medical University, 2018

Air quality monitoring is essential when it comes to protecting the urban population, especially that of big metropolises, from biohazards including biopathogens (BPs). This process is aided by different samplers and analyzers of aerosol pollutants, filters and disinfection systems. Their performance is tested using experimental aerosol formulations with a predetermined composition. Unfortunately, the majority of such systems available in Russia are only able to process a few hundred liters of air per time unit, which is too little. Big aerosol chambers (10 to 20 m3) are very expensive and may not fit into a lab, necessitating an extensive overhaul. In this work we present a workstation for the detection of BP markers under controlled conditions based on the microbiological safety box MSB-III-Laminar-C-1.5 (380.150.01) that was originally designed to test the performance of samplers and analyzers of experimental aerosol formulations. Our workstation can handle the majority of BSL-1-...

Fine particle concentrators for inhalation exposures—effect of particle size and composition

Journal of Aerosol Science, 1997

This paper presents the development and evaluation of ambient fine particle concentrators for conducting animal and human exposure studies. These systems utilize the technology of virtual impactors to concentrate particles in the range 0.15-2.5 pm. Ambient particles are first drawn at 5000 1 m-l through a preselective inlet that removes particles above 2.5 pm. Subsequently, the remaining aerosol is drawn through a series of virtual impactors, which increase particle concentration by a factor of about 10 and 30, for human and animal exposures, respectively. Results from the experimental characterization of the concentrators showed that the concentration emichment process occurs without any distortion in the size distribution and chemical composition of the sampled ambient aerosols. Furthermore, labile constituents of fine particles, such as volatile ammonium nitrate are preserved during this process.

New personal sampler for viable airborne viruses: feasibility study

Journal of Aerosol Science, 2005

Performance evaluation of six different aerosol samplers in a particulate matter generation chamber

Atmospheric Environment, 2009

The present study was carried out with the aim of evaluating the performance of six different aerosol samplers in terms of mass concentration, particle size distribution, and mass fraction for the international size-sampling conventions. The international sizesampling criteria were defined as inhalable, thoracic, and respirable mass fractions with 50% cutoff at an aerodynamic equivalent diameter of 100 mm, 10 mm, and 4 mm, respectively. Two Andersen, four total suspended particulate (TSP), two RespiCon, four PM 10 , two DustTrak, and two SidePak samplers were selected and tested to quantitatively estimate human exposure in a carefully controlled particulate matter (PM) test chamber. The overall results indicate that (1) Andersen samplers underestimate total suspended PM and overestimate thoracic and respirable PM due to particle bounce and carryover between stages, (2) TSP samplers provide total suspended PM as reference samplers, (3) TSP samplers quantified by a coulter counter multisizer provide no information below an equivalent spherical diameter of 2 mm and therefore underestimate respirable PM, (4) RespiCon samplers are free from particle bounce as inhalable samplers but underestimate total suspended PM, (5) PM 10 samplers overestimate thoracic PM, and (6) DustTrak and SidePak samplers provide relative PM concentrations instead of absolute PM concentrations.

Digital to flow converter for sampling of airborne particles

Personal size-separating impactor for sampling microbiological aerosols

American Industrial Hygiene Association journal, 1987

A commercially-available personal impactor was altered to sample viable microorganisms onto a semisolid, moist, gelatin medium rather than onto a stainless steel or filter surface. The Marple personal cascade impactor is an eight-stage sampler with predicted cut-offs of 20, 15, 10, 6, 3.5, 2, 1, and 0.61 microns for stages one to eight, at a flow rate of 2 L/min. The possibility was examined that using trays containing a small amount of gelatin medium in place of the thin, flat filters of the original design would alter the impactor's performance. A polydisperse aerosol of di-2-ethylhexyl phthalate (DEHP or DOP) was sampled directly into an aerodynamic particle sizer and through a stage of the personal impactor. The aerosol particles penetrating the tested stage were sized and counted, and the counts compared with those in the total aerosol. With a Mylar medium filter as the collecting substrate, the measured particle cut-offs (D50) for stages four to seven were 5.2, 3.4, 1.4, a...

CHART: a novel system for detector evaluation against toxic chemical aerosols

Scientific Reports, 2024

Concern over the possibility of deliberate dispersion of chemical warfare agents and highly toxic pharmaceutical based agents as persistent aerosols has raised the need for experimental assessment of current and future defensive capabilities of armed forces and law enforcement agencies. Therefor we herewith present the design, realization and validation of the Chemical Hot Aerosol Research Tool (CHART) as a validated and safe experimental setup for performance evaluation of chemical detection and identification equipment against chemical warfare agents and other highly toxic compounds. In the CHART liquid and solid compounds in solution or suspension are being dispersed as aerosols in a nebulization chamber. A broad dynamic particle size range can be generated, including particles known to be able to reach the lower respiratory tract. The aerosol generated is presented to the detection system-under-test while being monitored and characterized in real-time, using an optical particle counter and a time-of-flight aerosol analyzer, respectively. Additionally, the chemical composition of the aerosol is ex situ measured by analytical chemical methods. Evidently, in the design of the CHART significant emphasis was placed on laboratory safety and containment of toxic chemicals. The CHART presented in this paper has proven to be an indispensable experimental tool to study detectors and fieldable identification equipment against toxic chemical aerosols. Deliberate release of chemical warfare agents (CWAs) and pharmaceutical-based agents (PBAs) is of increasing concern, both from a civil security as from a military perspective 1-3. Both CWAs and PBAs are toxic chemical substances with a potential to injure, incapacitate or kill 4. The primary categories of CWAs are nerve agents, blister agents, choking agents and blood agents, of which nerve agents are the most precarious 5. PBAs include synthetic opioids, such as remifentanil and carfentanil with toxicities that even exceed those of nerve agents 6. In a briefing guide for first responders of the US Drug Enforcement Administration accidental exposure to these aforementioned synthetic opioids by first responders is considered a "real danger" 7. Many reports have been composed detailing developed symptoms of police officers, fire-fighters and medical service providers responding to incidents in environments where illicit drugs were present 8. Although nerve agent exposure is less common, terrorist organizations and rogue states have deployed nerve agents on civilians and armed forces 9,10. Whereas, based on their intrinsic toxicity, many nerve agents and PBAs are capable of causing serious injury or death, it is the dispersion method and the accuracy of its delivery that determines the actual human exposure and thereby the overall effect 11. Classical CWAs, including many nerve agents, typically are volatile liquids that are readily dispersed as vapors. Many of the conventional detection and identification systems are based on traditional analytical chemical analysis techniques, such as photoionization detectors, gas chromatography-mass spectrometry and ion mobility spectrometry 12. As such, these instruments are commonly reliant on the presence of a vapor 11. In contrast, the clandestine development of more advanced nerve agents known as the fourth generation agents or Novichock agents has led to persistent agents of very low volatility. The low to non-volatility of these compounds ensure that they can proficiently be generated as an aerosol and will remain in the aerosol phase, potentially entering the body through inhalation, dermal exposure or ingestion 12. The new generation of detection systems designed to detect low-volatile aerosols frequently include identification capabilities. These systems go beyond mere presence detection of a general agent class and have the capacity to identify the chemical composition of the aerosols, allowing for more precise responses and appropriate

An Air Sampler With Particle Filter Using Innovative Quad-Inlet Cyclone Separator and High Voltage Trap

IEEE Sensors Journal, 2019

The air sampler collects all floating particles which are different in size and it is necessary to retain only the size range of the interested objects. With our target in sampling the Fusarium spores having particle diameter from 10µm to 70µm, the sampler needs to eliminate particles <10µm and >70µm. This work proposes a novel sampler by combining a quad-inlet cyclone separator and high voltage trap. The small size cyclone is a new design having four inlets to intake the particles from any direction. This quad-inlet cyclone separator filters away large size particles. By applying di-electrophoretic force in the high voltage portion, the sampler eliminates small size particles. The combination of these two devices creates a system which works as a particle bandpass filter. To investigate the features as well as to study the appropriate parameters of the cyclone and the trap, numerical simulations were performed using Comsol Multiphysics. Simulation results indicate the bandpass ranges of wheat, turmeric and Fusarium samples are [19.5µm-75µm], [14.5µm-52.5µm] and [15.5µm-67µm]. Experimental results consolidate that the sampler reduces the presence of small size particles and especially filter well the particles having >70 µm in size. In addition, with homogeneous electric field in the high voltage trap, the sample distribution on the electrodes is fairly smooth. Using a strong vacuum pump, the internal air sample is cleaned very well for the next sampling. The designed particle trap can be widely applied in air sampling and analysis applications.

Performance Evaluation of a Novel Sampling and Measurement System for Exhaust Particle Characterization

SAE technical paper series, 2004

This paper presents a novel partial flow sampling system for the characterization of airborne exhaust particle emissions. The sampled aerosol is first conditioned in a porous diluter and then subsequent ejector dilutors are used to decrease its concentration to the range of the instrumentation used. First we examine the sensitivity of aerosol properties to boundary sampling conditions. This information is then used to select suitable sampling parameters to distinguish both the nucleation and the accumulation mode. Selecting appropriate sampling parameters, it is demonstrated that a distinct nucleation mode can be formed and measured with different instruments. Using these parameters we examine the performance of the system over transient vehicle operation. Additionally, we performed calculations of particle losses in the various components of the system which are then used to correct signals from the instruments. Several quality characteristics are then discussed, such as the repeatability and reproducibility of the measurements and the potential to derive total emission rate with a partial flow sampling system. Comparisons in different laboratories show that repeatability (intra-laboratory variability) is in the order of 10% for accumulation mode particles and 50% for nucleation mode ones. Reproducibility (inter-laboratory variability) values are in the range of ±20-30%. Finally, we compared laboratory size distributions with ambient samples obtained chasing a vehicle. This demonstrated that the sampling system accurately reproduced the accumulation mode particles as well as the potential for nucleation mode formation. This sampling system has

A new PIXE setup dedicated to the analysis of aerosol samples

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1990

A chamber was designed and built to simplify and expedite the PIXE/PIGE analysis of a large number of aerosol samples collected with an automated sampler. extensively used in background aerosol monitoring campaigns. This sampler collects the aerosol automatically on strips of Nuclepore filter membranes. each normally containing fourteen samples and two blanks. Eight such filter strips can be loaded into a revolving magazine in the chamber and analyzed in a simultaneous PIXE/PIGE analysis. A ninth filter frame holds a quartz plate for beam inspection and standard samples for quality assurance. The functions of the ehamber can be operated both manually or automatically.