A simple novel device for air sampling by electrokinetic capture.

BackgroundA variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable.ResultsAn air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air.ConclusionsThis work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing

Calibration of polyurethane foam (PUF) disk passive air samplers for quantitative measurement of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs): Factors influencing sampling rates.

PUF disk passive air samplers are increasingly employed for monitoring of POPs in ambient air. In order to utilize them as quantitative sampling devices, a calibration experiment was conducted. Time integrated indoor air concentrations of PCBs and PBDEs were obtained from a low volume air sampler operated over a 50d period alongside the PUF disk samplers in the same office microenvironment. Passive sampling rates for the fully-sheltered sampler design employed in our research were determined for the 51 PCB and 7 PBDE congeners detected in all calibration samples. These values varied from .57 to 1.55m(3)d(-1) for individual PCBs and from 1.1 to 1.9m(3)d(-1) for PBDEs. These values are appreciably lower than those reported elsewhere for different PUF disk sampler designs (e.g. partially sheltered) employed under different conditions (e.g. in outdoor air), and derived using different calibration experiment configurations. This suggests that sampling rates derived for a specific sampler configuration deployed under specific environmental conditions, should not be extrapolated to different sampler configurations. Furthermore, our observation of variable congener-specific sampling rates (consistent with other studies), implies that more research is required in order to understand fully the factors that influence sampling rates. Analysis of wipe samples taken from the inside of the sampler housing, revealed evidence that the housing surface scavenges particle bound PBDEs

Porous silica spheres as indoor air pollutant scavengers

Porous silica spheres were investigated for their effectiveness in removing typical indoor air pollutants, such as aromatic and carbonyl-containing volatile organic compounds (VOCs), and compared to the commercially available polymer styrene-divinylbenzene (XAD-4). The silica spheres and the XAD-4 resin were coated on denuder sampling devices and their adsorption efficiencies for volatile organic compounds evaluated using an indoor air simulation chamber. Real indoor sampling was also undertaken to evaluate the affinity of the silica adsorbents for a variety of indoor VOCs. The silica sphere adsorbents were found to have a high affinity for polar carbonyls and found to be more efficient than the XAD-4 resin at adsorbing carbonyls in an indoor environment

A comparative study of selected sorbents for sampling of aromatic VOCs from indoor air

Indoor air canbecome pollutedwith VOCs, and understanding the factors which affect adsorption of VOCs from indoor air is important for: (i) the accurate measurement of VOCs, and (ii) to apply mitigation strategies when high analyte concentrations are measured. In this study four VOCs (toluene, ethylbenzene, cumene and dichlorobenzene) were generated as a constant and controlled polluted air stream of VOCs from a dynamic atmospheric chamber. The effects of relative humidity, and sampling flow rate, on adsorption onto Tenax TA and the relatively new silica adsorbents SBA-15 or MCM-41 were studied

Improved atmospheric particle analyzer

Nephelometer measures aerosol particles in wide concentration and size distribution ranges. It measures the light scattered from the aerosol particles at a controlled sampling rate to ensure laminar flow through the sample tube, and thereby eliminate the need for sheath air

Faktor-faktor yang Berhubungan dengan Kualitas Bakteriologis Sumur Gali di Kelurahan Jatibarang Kecamatan Mijen Kota Semarang

Air penting bagi kehidupan, kebutuahn manusia akan air sangat kompleks antara lain untuk keperluan minum, masak, mandi dan mencuci. Persyaratan kualitas air di atur dalam peraturan pemerintah RI nomor 82 tahun 2001 tentang pengelolaan kualitas air dan pengendalian pencemaran air. Kelurahan Jatibarang sebagai salah satu Kelurahan di Kecamatan Mijen mempunyai jumlah penduduk, karakteristik lokasi dan kondisi pemenuhan kebutuhan air bersih khususnya kondisi sarana yang digunakan untuk keperluan rumah tangga belum memenuhi syarat kesehatan. Tujuan penelitian ini yaitu ingin mengetahui faktor-faktor yang berhubungan dengan kualitas bakteriologis sumur gali. Metode yang digunakan dalam penelitian ini adalah Explanatory Research dengan pendekatan Cross sectional Study. Populasi sebesar 220 unit sumur gali dengan sampel sebanyak 48 unit sumur gali. Teknik sampling yang digunakan adalah Purposive Sampling. Analisa statistik menggunakan uji Chi Square dengan derajat kemaknaan 95%. Hasil penelitian menunjukkan sumur gali dengan resiko pencemaran rendah 2 unit, sedang 13 unit, tinggi 23 unit dan amat tinggi 10 unit dengan kandungan bakteriologis antara 240/100 ml sampel hingga lebih dari 2.400/100 ml sampel air. Analisa statistik menunjukkan ada hubungan antara kondisi fisik sumur gali serta konstruksi jamban dengan kualitas bakteriologis air sumur gali. Tidak ada hubungan antara jarak sumur gali dengan jamban, jarak sumur dengan SPAL,praktik pemakaian sumur gali dengan kualitas bakteriologis air sumur gali. Kata Kunci: Sumur gali, Bakteriologis, Jamban, SPAL 25 buah, 1984 - 2002 Factors related with the bacteriological Quality of Dug well in Jatibarang Village, Mijen Subdistrict Semarang City A water is important for life, the human's necessity of water is very complex, namely for drinking, cooking, taking a bath, washing. The requirement of water quality is arranged is the governmental rules of Indonesia Republic No. 82/2001 about the manajement of water quality and the control of water pollution. Jatibarang village as one of village in Mijen Subdistrict has the population, location characteristict and fulfillment condition of clean water needs espicially the means condition used for household's need have not fulfilled the health requirement yet. The aim of the research is to know the factors related with the bacteriological quality of dug well. The methode used in this research was explanatory research with the approach of crossectional study. The population was in the amount of 220 units dug well with the samples were in the amount of 48 units of dug well. The sampling tecnique used for purposive sampling. The statistical analysis used X2 test with the degree of significancy is 95%. The result of research indicate that the dug well with low pollution risk is 2 units, medium is 13 units, high is 23 units, and very high is 10 units with the amount bacteriologycal is between 240/100 ml until >2400/100 ml of water sample. The statistical analysis indicate that there is a correlation between the physical condition of dug well and the privy construction with the water bacteriologycal quality of dug well. There is no correlation between the distant of dug well and the privy, well's distant with SPAL, the practice of dug well using with the water bacteriologycal quality of dug well. Keyword : Dug well, bacteriologycall, privy, SPA

Determination and microbial survival of cryogenic whole air sampling conditions Final report, 27 Dec. 1964 - 27 Jul. 1965

Survival of microorganisms exposed to shock wave and cryogenic temperature during whole air sampling of upper atmospher

Ground vibration test and flutter analysis of air sampling probe

The Dryden Flight Research Facility of NASA Ames Research Center conducted a ground vibration test and a flutter analysis of an air sampling probe that was to be mounted on a Convair 990 airplane. The probe was a steel, wing-shaped structure used to gather atmospheric data. The ground vibration test was conducted to update the finite-element model used in the flutter analysis. The analysis predicted flutter speeds well outside the operating flight envelope of the Convair 990 airplane

Influence of the public transportation system on the air quality of a major urban center. A case study: Milan, Italy

A sampling campaign was conducted in the city of Milan, Italy before and during a transportation strike in January 2004. This strike provided a unique opportunity to investigate the influence of public transportation on the air quality in a major metropolitan area. Twenty-four air samples were collected each day around the city on January 2nd, 7th and 9th. The samples were analyzed for methane, carbon monoxide, non-methane hydrocarbons (NMHCs), halocarbons and alkyl nitrates. Significant differences in the mixing ratios were observed among the three days of sampling, with January 2nd showing the lowest concentrations as a result of decreased activity in the city during the holiday season. January 9th showed the highest NMHC concentrations because of increased vehicular activity in the city due to a public transportation strike. This paper investigates the correlation between the increased number of vehicles and decreased air quality because of a reduction in public transportation. Computer simulations were able to reproduce measurements of ozone production during the January 2004 strike and a July 2005 strike. The measurements and simulations suggest that reduced VOC emissions due to the existence of public transportation lowers peak ozone by 11-33% during the summer months. © 2008 Elsevier Ltd. All rights reserved