Since 2019, when the first cases were reported, people have been fighting against the outbreak of Covid-19 for more than two years. Today, the new coronavirus continues to evolve and mutate, and several new mutant coronavirus strains have appeared one after another. Outbreaks caused by infection with the new coronavirus and its mutant strains are still widespread worldwide.
Professional researchers were working on viruses and respiratory infections from Cambridge University Hospital, Cambridge, UK; Cambridge Clinical Laboratory; University of Maastricht, The Netherlands; University Hospital of Liège, Belgium; and University of Florence, Italy. In the journal Nature Portfolio the jointly formed research team published a technical article titled “The SARS CoV 2 viral load in COVID 19 patients is lower on face mask flters than on nasopharyngeal swabs”. In this work, the researchers used the Palas® aerosol sensor welas® 2100 HP for experiments simulating respiratory aerosols. Palas® is helping the researchers investigate the feasibility of using masks to replace traditional nasopharyngeal swabs for COVID-19 virus detection.
An aerosol generating system connected to a particle counter was used to characterize aerosols. Particles generated by aerosolizing a test solution using an OMRON nebulizer were mixed with air and sized with a Welas particle counter.
The aerosol generating system was adapted to disperse inactivated virus onto filters. Particles containing inactivated virus diluted in DMEM were generated using an OMRON nebulizer, mixed with air, and drawn onto an electrostatic filter by a vacuum pump.
In this article, the authors describe how they simulated inactivated viral aerosols with diameters of 0.3-2 µm (average mass diameter of 0.9 µm). The simulated aerosol viral particles were distributed on the masks and compared with test results from nasopharyngeal swabs collected from patients with confirmed Covid-19.
The results showed lower sensitivity of the filter samples (8.5% less than nasopharyngeal swabs). This indicates that the number of viral particles collected from the mask filters was below the detection limit in all patients except those with the highest viral load. This also indicates that the use of facial masks rather than diagnostic nasopharyngeal swabs is inappropriate at the time of COVID-19 diagnosis. However, detection of nucleic acids by facemask filters may have other applications that require further research.
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Advantage
· The sensors are easy to replace
· The world’s smallest and most robust sensors in the 2000 series
· Very good agreement of all sensors in terms of particle size and concentration (see Graph 1)
· Minimization of particle losses in long sampling lines by simply installing the sensor directly at the sampling location
· Sensors for in-situ measurements
· Measurement in potentially explosive environments with the 2000 series (without heating)
· Easy to clean
· Simple operation
· Reliable function
· Low maintenance
· Reduces your operating expenses
Application
· Determination of the separation efficiency of car interior filters, engine air filters, room air filters, compressed air filters, vacuum cleaner filters, cleanable filters, electrostatic precipitators, oil separators, cooling lubricant separators, wet scrubbers, cyclones and other separators
· Isothermal and isobaric particle size and quantitative determination, for instance in the automobile, chemical, pharmaceutical and food industries
· Analysis of fast, transient processes
· Inspection of smoke detectors
· Particle formation for cloud formation
· Emission measurements
· Immission measurements
Palas® China will arrange a series of online webinars both in English and Chinese for Ambient air quality continuous monitoring system, Palas® SMPS scanning mobility particle sizer, Palas® Promo® & Aerosol Generator & Dilution system, ISO 16890 filter media tester, Palas® MFP 3000 G, ISO 29463-3 filter media tester, Palas® MFP Nano plus 4000, ISO 17536 Fractional filtration efficiency tester of Oil Mist Separator, Palas® HMT 1000, as well as Particle Distribution Measurement Devices Introduction – Optical Scattering Method and many other solutions. If interested in the webinars for our products, you are more than welcome to register on our official website and get the latest webinar plan!
Topic：How to Monitor Workplace Dust and Particle Size Distribution Using a Portable Particle Size Spectrometer
Time：Wednesday, May 11, 2022 15:00-16:00
Presenter：Mr. Yi Fangjie
Market Manager Industry and Science at Palas® China
You are welcome to register for the conference!
Register online now to participate in our webinars if interested