The Electrical Sensing Zone Method (The Coulter Principle)

On examining the published results of comparisons of sampling with Institute of Occupational Medicine (IOM) (Edinburgh, U.K.) samplers and 37-mm closed-face cassettes it was observed that they usually do not take into account the dust deposited on the walls of the cassettes. As the method used by the Institut National de Recherche et de Sécurité, France (INRS), to analyze metals includes the analysis of these deposits, it was decided to evaluate the differences obtained between these samplers when using this method. The essays were conducted in three different plants, and repetitive static samplings were carried out to compare 2 L/min, IOM cassettes and 1 or 2 L/min 37-mm closed-face cassettes. The airborne particles were also sampled simultaneously for granulometric analysis. Gravimetric determinations of sampled aerosol were obtained by weighing 37-mm filters and IOM cassettes, and the aerosol collected on the filters and the particles deposited on the walls were analyzed separately for both types of samplers by atomic spectrometry for metals content. The intra-sampler variability and inter-sampler ratios were then determined. Although results obtained for gravimetric analysis are comparable to those published elsewhere (ratio IOM/37-mm much higher than 1), the metal analysis revealed a close agreement between the results obtained with the three sampling methods tested when the wall deposits were taken into account. As published previously, the ratio of wall deposits to filter collected aerosol for 37-mm cassettes is variable, and it would appear to be very difficult to find an appropriate correction factor applicable when only the filter is analyzed. Were these results to be confirmed by further experiments, sampling with 37-mm closed-faced at 1 or 2 L/min or with an IOM sampler would be equivalent for all pollutants for which the analytical method allows the recovery of walls deposit.

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“…(25) These samplers were placed every 10 centimeters along a metallic bar situated about 1 m 50 cm from the ground, always in the same sequence:…”

Section: Methodsmentioning

confidence: 99%

Field Comparison of 37-mm Closed-Face Cassettes and IOM Samplers

Demange

Görner

Elcabache

et al. 2002

Applied Occupational and Environmental Hygiene

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“…One millilitre of this suspension was diluted in an electrolyte solution (Beckman Coulter s , Isoton s II diluents). The particle sizing analyser uses the Coulter s principle or Electrical Sensing Zone Method (Allen, 1981;Lines, 1991) and provides equivalent volume diameter (d v ) measurements of particles (analysis of 100 mL, 30-mm calibrated aperture), using 100 channels.…”

Section: Particle Number Concentration and Particle Size Distributionmentioning

confidence: 99%

Aerosolisation of Escherichia coli and associated endotoxin using an improved bubbling bioaerosol generator

Simon

Duquenne

Koehler

et al. 2011

Journal of Aerosol Science

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“…We propose that resistive pulse sensing is an enabling technique for characterizing aggregated amyloidogenic peptides, since it is the only technique that measures single particles volumetrically and is, therefore, particularly well-suited for characterizing particles with irregular shapes. 14 …”

mentioning

confidence: 99%

Single-Particle Characterization of Aβ Oligomers in Solution

et al. 2012

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Determining the pathological role of amyloids in amyloid-associated diseases will require a method for determining the dynamic distributions in size and shape of amyloid oligomers with high resolution. Here, we explored the potential of resistive-pulse sensing through lipid bilayer-coated nanopores to measure the size of individual amyloid-β oligomers directly in solution and without chemical modification. This method classified individual amyloid-β aggregates as spherical oligomers, protofibrils, or mature fibers and made it possible to account for the large heterogeneity of amyloid-β aggregate sizes. The approach revealed the distribution of protofibrillar lengths as well as the average cross-sectional area of protofibrils and fibers.

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The Electrical Sensing Zone Method (The Coulter Principle)

Cited by 30 publications

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Field Comparison of 37-mm Closed-Face Cassettes and IOM Samplers

Field Comparison of 37-mm Closed-Face Cassettes and IOM Samplers

Aerosolisation of Escherichia coli and associated endotoxin using an improved bubbling bioaerosol generator

Single-Particle Characterization of Aβ Oligomers in Solution

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