WO2001040793A1 - Instrument simple permettant de mesurer des gaz - Google Patents

Instrument simple permettant de mesurer des gaz Download PDF

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Publication number
WO2001040793A1
WO2001040793A1 PCT/GB2000/004567 GB0004567W WO0140793A1 WO 2001040793 A1 WO2001040793 A1 WO 2001040793A1 GB 0004567 W GB0004567 W GB 0004567W WO 0140793 A1 WO0140793 A1 WO 0140793A1
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WO
WIPO (PCT)
Prior art keywords
gas
bed
sensor
temperature
desorption
Prior art date
Application number
PCT/GB2000/004567
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English (en)
Inventor
David Edward Williams
Maher Kalaji
Ljuibov Morris
Daren Joseph Caruana
Original Assignee
Capteur Sensors And Analysers Limited
Trwyn Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Capteur Sensors And Analysers Limited, Trwyn Limited filed Critical Capteur Sensors And Analysers Limited
Publication of WO2001040793A1 publication Critical patent/WO2001040793A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • G01N1/2273—Atmospheric sampling
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • G01N1/2202—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling
    • G01N1/2214—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling by sorption
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • G01N1/24—Suction devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • G01N1/2273—Atmospheric sampling
    • G01N2001/2276—Personal monitors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N2030/0075—Separation due to differential desorption
    • G01N2030/008—Thermal desorption

Definitions

  • Simple Instrument For Measuring Gases This describes simple, reliable, low-maintenance methods to monitor and identify volatile organic compounds at very low concentrations in air
  • the system may be used for health and safety monitoring for compounds such as formaldehyde glutaraldehyde and benzene It may be used to detect and characterise solvent contamination (such as by chlorinated hydrocarbons like 1 ,1 ,1 ,tr ⁇ chloroethane or by ketones like methyhsobutylketone) in soil and water by drawing air through the sample then analysing the air for the contaminant
  • GC gas chromatography
  • FIG 1 shows the concept in outline
  • species present in air which may be drawn through the sample
  • TPD temperature-programmed desorption
  • a gas-sensor device which may be a gas-sensor array
  • the absorbent bed may be of various sizes depending on the purpose of use, provided it can be uniformly heated during the desorption phase
  • the bed volume will be no larger than 10,000mm 3 although much smaller beds are envisaged for miniaturised versions - preferably no greater
  • the bed had a volume of about 39mm 3
  • the sensor device is a gas-sensitive resistor based on a heated semiconducting oxide
  • the second in which the sensor is a gas-sensitive resistor based on a heated semiconducting oxide in which the sensor is a multiple- electrode device
  • the third in which three multiple-electrode semiconducting oxide gas-sensitive resistors are used, each sensor operating at different temperature
  • the fourth in which the sensor is a simple electrochemical cell such as may be found in a hand-held breath alcohol measuring instrument
  • Absorbents There are a variety of adsorbent resins and synthetic or activated charcoals (Tenax TA, Tenax GR Chromosorb 105, Anasorb 747, Chromosorb 106, Carbotrap Carbosorb Carbosieve) which have been exhaustively evaluated and are widely used to trap volatile and semi-volatile organics from gas or liquid samples when utilising purge and trap techniques for analysis of trace constituents
  • Absorbent resins are specified in several EPA methods for air and water testing (SW-846' methods 8240/8260) They may be crudely characterised by their "break-through volume" (BTV) the volume of carrier gas/unit weight of adsorbent which causes the analyte to migrate from front to back of the adsorbent bed The BTV decreases with increasing temperature, and the decrease can be used to define a desorption temperature for the volatile The parameters are generally useful for the choice of adsorbents Other authors have used adsorption isotherm parameters to characterise adsorb
  • ⁇ 0% activation energy for deso ⁇ tion and ko is a standard rate ⁇ xistant), T gas phase concentration, ⁇ adsorbed concn (both scaled to mo), h, A: bed depth, cross-sectional area; v: gas volume flow rate; r. temperature ramp rate, mo. initial concentration adsorbed
  • the panel shows how to model the adsorbent bed, shows how the control parameters (bed volume, volume flow rate of gas temperature ramp rate) group
  • the parameters controlling the proposed method are different for the absorption and the desorption cycles
  • the usefulness of the model is that it shows what measurements to take to choose an absorbent, then how to design the operating conditions for the bed to obtain the maximum sensitivity and discrimination and how to trade these off against one another, utilising the performance characteristics of the sensors
  • discrimination based on the desorption time and temperature being different for different compounds
  • the bed can therefore be used both as a concentrator and as a crude GC column and the system as a whole has two sources of information on the chemical contaminants present the relative signals on the different sensor electrodes if multiple-electrode sensors are used and on the different sensors in the array if more than one sensor is used, and the evolution of these signals with time and temperature during the desorption
  • Flash desorption (rapid temperature ramp then hold) would give maximum sensitivity but discrimination based only on the sensor characteristics This is appropriate for the first level identification of contamination Further discrimination using the bed characteristics would require more sophisticated control of the bed and choice of adsorbents (including the possibility of a layered bed with two different absorbents)
  • adsorption could proceed either as a front passing through the bed or uniformly build up in the bed, depending on adsorption and desorption rate constants and v, the gas flow velocity TPD depends upon v/hr (h bed depth, r temperature ramp rate) with peak temperature reliant on ⁇ E ⁇ (desorpt ⁇ on activation energy) and on the shape of the absorption profile
  • the adsorption profile could easily be different for different gases If, for example, one gas were concentrated near the bed entry, but started to desorb at a low temperature its exit from the bed would be delayed to a significantly hither temperature, determined by the time delay for movement down the bed If there were another gas, more uniformly distributed but desorbing
  • Fuel Cells A fuel cell is an electrochemical cell in which an oxidisable fuel is supplied to one electrode, the anode, and an oxidant, normally oxygen, is supplied to the cathode No voltage is applied across the cell, but the electrons generated at the anode flow through the external circuit to the cathode where oxygen is reduced The voltage measured across a load resistance indicates the extent of the faradaic oxidation at the anode Fuel cells are routinely used as electrochemical sensors for a variety of volatile organics, including alcohols and aldehydes The best known application is in the measurement of ethanol in breadth These devices have advantages of low cost and power consumption
  • the absorbent bed can be mounted separately from the sensors or can be incorporated into the sensor housing in a monolithic unit Several such units can then be operated in one instrument from a common controller and data processing system Examples
  • Example 1 A small bed (lcm deep, 1cm 2 cross section) of activated charcoal or molecular sieve type 4A was mounted in a small tube furnace with flowing air and with the gas sensor in the exit stream
  • Figure 2(a) (result for zeolite 4A, ramp 5°/m ⁇ n, air flow 12cm 3 /m ⁇ n , sensor 3-gap Cr, 8 T1 0 2 O 3 device) illustrates TPD of acetone in air, and the deduction of decomposition of acetone by virtue of the different sensor signals on the multi-electrode array
  • the difference between the signals on the different electrodes arises because the gases burn at different rates within the porous sensor layer
  • a simple way of displaying the consequences is to plot an "operating line" of resistance measured at one pair against that measured at another pair As the gas concentration varies, a line which is characteristic of the gas is traced out in the multidimensional space defined by the measurements e g as shown in Figure 2(b), the slope using 2 pairs identifies
  • Figure 3(a) and (b) illustrates this for a mixture of acetone and ethanol injected onto charcoal previously contaminated with tnchloroethylene, with the identification of the desorbing gases based upon the characteristic operating line slope for that gas
  • Example 2 As in example 1 a small bed (lcm deep, 1 cm cross section) of activated charcoal was mounted in a small tube furnace with flowing air The detector assembly was an array of three 3-gap CTO devices, each operated at different temperature
  • Figure 4 shows the measurement of trace volatile organic compounds in the air of Central London, through the day, and compares the signal from this simple device with that from an elaborate gas chromatograph system measuring benzene The correlation between the two methods is clear
  • Example 3 The system of example 2 was used to sample exhaust gases at the rear of a petrol-engined car The output from the analytical system shows discrimination of a number of components of the exhaust ( Figure 5)
  • Example 4 The sensor signals from the 3-sensor, 3-gap array were analysed using the method of Principle Components
  • Figure 6 shows
  • Example 5 To increase the discrimination of the system, the outputs from the individual sensors can be divided into time slots, each time slot corresponding to a different range of temperature on the desorption cycle Each sensor signal for each time slot can be treated as an independent variable for input to a pattern recognition system Hence the simple use of an absorbent bed which is periodically heated greatly increases the effective number of sensors in the array and gives better discrimination This method has particular application to "Electronic Noses"
  • any given gas can be represented as a limited set of parameters These are the adsorption and desorption rate constants, the desorption activation energy and the sensor response characteristics For a multiple-electrode device, there are two of these, describing sensitivity and gas decomposition rate within the sensor structure Alternatively the sensor parameters can be the relative sensitivity of different sensors to the particular gas Identification and quantification of a gas mixture can then be reduced to a statistical problem of hypothesis testing Given a library of parameters, what is the best fit (including uncertainty estimate) that can be obtained taking one gas at a time, then two, then three and so on One stops when the statistical uncertainty does not improve when more gases are added into the model (the model being a selected set of gases, with their concentrations), and reports the various hypotheses that give a satisfactory fit, together with the estimates of uncertainty
  • Example 7 The sensor used in this work was a Glutarmeter (PPM Ltd, UK), which housed a fuel cell that had the following specifications Electrolyte, Sulphuric acid (6M); Anode and cathode, platinum black on PVC.
  • the cell is routinely used to measure glutaraldehyde levels down to 1 ppm. Tightening safety regulations require that the operational range be extended to 0.1 ppm or less. At this level, there is a severe problem of interference with alcohols which may also be present at low levels in the air.
  • a small glass tube (6 mm inner diameter), containing TENAX TA 80/100 mesh (2 cm) was mounted into a small furnace. A pump was used to pull the air through the tube past the fuel cell.
  • Example 8 identification and measurement of hydrocarbons in air at part-per-billion level.
  • the absorbent bed is made from three pieces of machinable ceramic. A length of resistance wire acts as the heating element and surrounds the bed.
  • the bed temperature is controlled by a thermocouple and power controller, the thermocouple being inserted into the centre of the bed.
  • the bed is 5mm diameter and approximately 2mm thick and preferably comprises the well-known adsorbent "Tenax®" (a hydrophobic aromatic polymer material which in various forms also incorporates activated charcoal).
  • Tex® a hydrophobic aromatic polymer material which in various forms also incorporates activated charcoal.
  • Tenax is normally used as an adsorbent of hydrocarbons from air at ambient temperature, with the hydrocarbons being desorbed into a gas chromatograph or similar instrument by heating in a stream of nitrogen.
  • sensitivity was obtained by the accumulation of the gases to be determined on the absorption bed, the required sensitivity being determined simply by the length of the adsorption time
  • Species identification was obtained though both the characteristics of the bed and those of the sensor array.
  • the desorption characteristics of the bed gave an indication of the boiling temperature of the different species present in the gas stream, and a further indication of general functional type.
  • the sensor array produced an output which was a simple spectrum, having 6 or 8 measurement values in the case of the sensors used here.
  • the spectrum of a particular gas was simply the relative values of the array output for that gas. Whilst there was considerable spectral overlap in the characteristics of different gases, the response pattern for a particular gas was generally indicative of its reactivity towards oxidation on the sensor surface. a) Partial identification using the desorption characteristics of the bed.
  • Figure 8 shows the response of one of the sensors in the array to the desorption respectively of toluene and o-xylene, following adsorption for 15 min and desorption with a temperature ramp at 10C/min. Measurement at sub-ppb level is clear. The peak area increases linearly with the original concentration in the gas phase. There is also a systematic correlation of peak height with gas phase concentration. It is also clear that toluene and xylene have different characteristic peak temperature and peak width for desorption.
  • Figure 9 shows the response on a single sensor to the desorption of a range of different aliphatic and aromatic hydrocarbons, all adsorbed onto the bed from air containing approximately 10ppb of the individual species.
  • the peak temperature for desorption correlates linearly with the boiling temperature of the compound.
  • the peak width for the desorption trace correlates with the peak temperature, again linearly.
  • the peak width for the aliphatic compounds is systematically greater than for the aromatics.
  • the correlation of peak width with peak temperature has approximately the same slope for the two series of compounds, but the correlation line for the aliphatics is displaced towards higher peak width with respect to the correlation line for the aromatics iv because the bed is thin, the behaviour can be described mathematically according to a model which assumes uniform loading of the species from the gas phase onto the bed, there is a well-defined peak shape, desc ⁇ bable by two parameters only for each compound
  • a standard signal processing method can be used to express the full set of traces obtained off the sensor array, in response to the desorption of a gaseous mixture from the bed, as a sum of such spectra
  • the objective is to find the minimum number of such spectra which, when added together, will represent the output of the array in response to the thermal desorption of gases from the bed
  • the individual spectra are constrained to be fixed for the whole desorption trace
  • the result is a set of desorption traces and a set of spectra, one for each trace, such that when the individual traces are added the set of signals in response to the desorption is reproduced
  • Figure 11 shows an example of deconvolution of the trace obtained for the headspace vapour from a sample of contaminated groundwater, using array (I) for the measurement
  • the resulting individual desorption traces represent the deposition of components whose response spectra are too similar to be distinguished
  • These individual traces can then be further deconvoluted as a sum of peaks of the defined shape known for thermal desorption from
  • PCA principal components Analysis
  • Figure 12 shows the result of PCA for a range of aromatic hydrocarbons
  • the first principal component (PC1 ) is related to the peak desorption temperature and hence to the boiling temperature of the compound
  • the second principal component (PC2) is related to the variance of the sensor signal outputs and hence to the reactivity of the compound
  • a clear resolution of a range of related aromatic hydrocarbons is shown d)
  • Special methodologies necessary for the analysis of the headspace vapour of contaminated ground water Adsorption and thermal desorption of vapours obtained by passing air through a contaminated ground water does not directly lead to a useful result because, when the vapour is saturated in water, water adsorbs strongly on the Tenax, giving a surface which is essentially water and which therefore does not adsorb the organics strongly Water desorbing from the Tenax also gives a signal on the sensor array, which tends to mask the signals due to the
  • One example would be the combination of an infra-red source and detector with a crude band pass filter to replace the spetrometer normally used.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Molecular Biology (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
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  • General Health & Medical Sciences (AREA)
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  • Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Abstract

L'invention concerne un instrument comprenant un lit d'adsorption et de désorption de gaz, un système de chauffage du lit, et un capteur de gaz. Ce capteur fournit une réponse sélective en fonction du gaz devant être identifié ou surveillé. Il est relié au lit de manière à détecter le gaz désorbé par ce dernier sous l'effet du chauffage.
PCT/GB2000/004567 1999-11-29 2000-11-29 Instrument simple permettant de mesurer des gaz WO2001040793A1 (fr)

Applications Claiming Priority (2)

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GB9928199.0 1999-11-29
GBGB9928199.0A GB9928199D0 (en) 1999-11-29 1999-11-29 Simple instrument for measuring gases at very low concentration in air

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1441212A1 (fr) * 2003-01-21 2004-07-28 Delphi Technologies, Inc. Détecteur d'alcool éthylique et son utilisation
WO2006073434A2 (fr) * 2004-04-21 2006-07-13 Honeywell International Inc. Microanalyseur viii séquentiel
EP1992945A3 (fr) * 2007-05-16 2009-02-25 Honeywell International Inc. Capteur autocalibrant de gaz à l'état de trace
US7654129B2 (en) 2005-05-17 2010-02-02 Honeywell International Inc. Sensor with an analyte modulator
EP2167944A2 (fr) * 2007-07-25 2010-03-31 University Of Louisville Research Foundation, Inc. Dispositifs et procédés de collecte d'analyte
US8569691B2 (en) 2009-11-24 2013-10-29 University Of Louisville Research Foundation Preconcentrator for analysis instruments
US8771613B2 (en) 2008-07-31 2014-07-08 University Of Louisville Research Foundation, Inc. Large volume analyte preconcentrator
CN104075984A (zh) * 2014-06-20 2014-10-01 江苏中宜生态土研究院有限公司 一种污染泥土修复后评价系统
EP3185011A1 (fr) 2015-12-23 2017-06-28 Commissariat À L'Énergie Atomique Et Aux Énergies Alternatives Capteur de gaz a selectivite amelioree et a compacite augmentee
RU2745392C2 (ru) * 2015-09-11 2021-03-24 Конинклейке Филипс Н.В. Многослойная сорбционная трубка и ее применение
WO2022101598A1 (fr) * 2020-11-11 2022-05-19 Roboscientific Ltd Méthode et appareil de détection de maladies bactériennes, virales et/ou parasitaires
RU2745392C9 (ru) * 2015-09-11 2022-08-15 Конинклейке Филипс Н.В. Многослойная сорбционная трубка и ее применение
EP4010694A4 (fr) * 2019-08-06 2023-08-30 Computational International LLC Système et procédé de surveillance de la présence de composés organiques volatils

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5469369A (en) * 1992-11-02 1995-11-21 The United States Of America As Represented By The Secretary Of The Navy Smart sensor system and method using a surface acoustic wave vapor sensor array and pattern recognition for selective trace organic vapor detection
US5789659A (en) * 1993-08-05 1998-08-04 Capteur Sensors & Analysers Ltd. Monitoring of multiple-electrode gas sensors

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5469369A (en) * 1992-11-02 1995-11-21 The United States Of America As Represented By The Secretary Of The Navy Smart sensor system and method using a surface acoustic wave vapor sensor array and pattern recognition for selective trace organic vapor detection
US5789659A (en) * 1993-08-05 1998-08-04 Capteur Sensors & Analysers Ltd. Monitoring of multiple-electrode gas sensors

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KINDLUND A ET AL: "QUARTZ CRYSTAL GAS MONITOR WITH A GAS CONCENTRATING STAGE", SENSORS AND ACTUATORS B,ELSEVIER SEQUOIA S.A., LAUSANNE,CH, vol. 6, 1984, pages 1 - 17, XP000937545, ISSN: 0925-4005 *
POOLE C F ET AL: "Determination of kinetic and retention properties of cartridge and disk devices for solid-phase extraction", JOURNAL OF CHROMATOGRAPHY B: BIOMEDICAL SCIENCES & APPLICATIONS,NL,ELSEVIER SCIENCE PUBLISHERS, vol. 689, no. 1, 7 February 1997 (1997-02-07), pages 245 - 259, XP004054194, ISSN: 0378-4347 *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1441212A1 (fr) * 2003-01-21 2004-07-28 Delphi Technologies, Inc. Détecteur d'alcool éthylique et son utilisation
WO2006073434A2 (fr) * 2004-04-21 2006-07-13 Honeywell International Inc. Microanalyseur viii séquentiel
WO2006073434A3 (fr) * 2004-04-21 2006-12-28 Honeywell Int Inc Microanalyseur viii séquentiel
US7654129B2 (en) 2005-05-17 2010-02-02 Honeywell International Inc. Sensor with an analyte modulator
EP1992945A3 (fr) * 2007-05-16 2009-02-25 Honeywell International Inc. Capteur autocalibrant de gaz à l'état de trace
US7975525B2 (en) 2007-05-16 2011-07-12 Honeywell International Inc. Self-calibrating sensor
EP2167944A2 (fr) * 2007-07-25 2010-03-31 University Of Louisville Research Foundation, Inc. Dispositifs et procédés de collecte d'analyte
EP2167944A4 (fr) * 2007-07-25 2013-09-25 Univ Louisville Res Found Dispositifs et procédés de collecte d'analyte
US8771613B2 (en) 2008-07-31 2014-07-08 University Of Louisville Research Foundation, Inc. Large volume analyte preconcentrator
US8569691B2 (en) 2009-11-24 2013-10-29 University Of Louisville Research Foundation Preconcentrator for analysis instruments
CN104075984A (zh) * 2014-06-20 2014-10-01 江苏中宜生态土研究院有限公司 一种污染泥土修复后评价系统
RU2745392C2 (ru) * 2015-09-11 2021-03-24 Конинклейке Филипс Н.В. Многослойная сорбционная трубка и ее применение
US11054412B2 (en) 2015-09-11 2021-07-06 Koninklijke Philips N.V. Multi-bed sorbent tubes and use thereof
RU2745392C9 (ru) * 2015-09-11 2022-08-15 Конинклейке Филипс Н.В. Многослойная сорбционная трубка и ее применение
EP3185011A1 (fr) 2015-12-23 2017-06-28 Commissariat À L'Énergie Atomique Et Aux Énergies Alternatives Capteur de gaz a selectivite amelioree et a compacite augmentee
US10788470B2 (en) 2015-12-23 2020-09-29 Commissariat A L'energie Atomique Et Aux Energies Alternatives Compact gas sensor with enhanced selectivity
EP4010694A4 (fr) * 2019-08-06 2023-08-30 Computational International LLC Système et procédé de surveillance de la présence de composés organiques volatils
WO2022101598A1 (fr) * 2020-11-11 2022-05-19 Roboscientific Ltd Méthode et appareil de détection de maladies bactériennes, virales et/ou parasitaires

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