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Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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Time Weighted Average Concentration Monitoring Based on Thin Film Solid Phase Microextraction
Environmental Science & Technology, 2017Co-Authors: Fardin Ahmadi, Chris Sparham, Ezel Boyacı, Janusz PawliszynAbstract:Time weighted Average (TWA) passive sampling with thin film solid phase microextraction (TF-SPME) and liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for collection, identification, and quantification of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, 2-phenylbenzimidazole-5-sulfonic acid, octocrylene, octylmethoxycinnamate, butylmethoxydibenzoylmethane, triclocarban and triclosan in the aquatic environment. Two types of TF-SPME passive samplers, including a retracted thin film device using a hydrophilic lipophilic balance (HLB) coating, and an open bed configuration with an octadecyl silica-based (C18)coating, were evaluated in an aqueous standard generation system. Laboratory calibration results indicated that the thin film retracted device using HLB coating is suitable to determine TWA concentrations of polar analytes in water, with an uptake that was linear up to 70 days. In open bed form, a one-calibrant kinetic calibration technique was accomplished by loading benz...
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Development and Application of a Needle Trap Device for Time-Weighted Average Diffusive Sampling
Analytical chemistry, 2008Co-Authors: Ying Gong, In-yong Eom, Da-wei Lou, Dietmar Hein, Janusz PawliszynAbstract:A simple, cost-effective analysis combining solventless extraction, thermal desorption, and determination of volatile organic compounds (VOCs) was developed and validated. A needle trap device (NTD) packed with the sorbent Carboxen1000 was used as a Time-Weighted Average (TWA) diffusive sampler to collect target compounds by molecular diffusion and adsorption to the packed sorbent. This process can be described with derivations of Fick’s first law of diffusion, which expresses the relation between the TWA concentrations to which the passive sampler is exposed and the mass of analytes adsorbed to the packed sorbent in the sampler. The effects of experimental factors such as temperature, pressure, humidity, and face velocity were taken into account in applying diffusive sampling under nonideal conditions. This study demonstrates that NTD is effective for air analysis of benzene, toluene, ethylbenzene, and o-xylene (BTEX), due to the good adsorption/desorption quality of Carboxen 1000 and to the special geom...
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Time-Weighted Average water sampling in Lake Ontario with solid-phase microextraction passive samplers.
Environmental science & technology, 2007Co-Authors: Gangfeng Ouyang, Wennan Zhao, Mehran Alaee, Leslie M. Bragg, Zhipei Qin, Janusz PawliszynAbstract:In this study, three types of solid-phase microextraction (SPME) passive samplers, including a fiber-retracted device, a polydimethylsiloxane (PDMS)-rod and a PDMS-membrane, were evaluated to determine the time weighted Average (TWA) concentrations of polycyclic aromatic hydrocarbons (PAHs) in Hamilton Harbor (the western tip of Lake Ontario, ON, Canada). Field trials demonstrated that these types of SPME samplers are suitable for the long-term monitoring of organic pollutants in water. These samplers possess all of the advantages of SPME: they are solvent-free, sampling, extraction and concentration are combined into one step, and they can be directly injected into a gas chromatograph (GC) for analysis without further treatment. These samplers also address the additional needs of a passive sampling technique: they are economical, easy to deploy, and the TWA concentrations of target analytes can be obtained with one sampler. Moreover, the mass uptake of these samplers is independent of the face velocity, or the effect can be calibrated, which is desirable for long-term field sampling, especially when the convection conditions of the sampling environment are difficult to measure and calibrate. Among the three types of SPME samplers that were tested, the PDMS-membrane possesses the highest surface-to-volume ratio, which results in the highest sensitivity and mass uptake and the lowest detection level.
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Time-Weighted Average water sampling with a diffusion-based solid-phase microextraction device.
Journal of chromatography. A, 2006Co-Authors: Gangfeng Ouyang, Wennan Zhao, Mehran Alaee, Janusz PawliszynAbstract:A new diffusion-based solid-phase microextraction (SPME) Time-Weighted Average (TWA) field water sampling device was developed and investigated by field trial. The sampler is constructed with copper tube and caps and a commercial SPME fiber assembly. The device possesses all advantages of SPME; it is solvent-free, reusable, combines sampling, isolation and enrichment into one step, and the fiber can be directly injected into a gas chromatograph for analysis with a commercial SPME fiber holder, without further treatment. Field trials in Laurel Creek (Waterloo, Ont., Canada) and Hamilton Harbour (Hamilton, Ont., Canada) illustrated that the device is durable, easy to deploy, and the mass uptake of the device is independent of the face velocity. The device provides good precision [relative standard deviations (RSDs) are less than 20%] and the data obtained with this device are quite comparable to those obtained with the spot sampling method, which demonstrates that the newly developed SPME water sampling device is suitable for long-term monitoring of organic pollutants in water.
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On-rod standardization technique for Time-Weighted Average water sampling with a polydimethylsiloxane rod.
Journal of chromatography. A, 2006Co-Authors: Wennan Zhao, Gangfeng Ouyang, Mehran Alaee, Janusz PawliszynAbstract:In this study, a polydimethylsiloxane (PDMS) rod was developed as a passive sampler, based on the solid-phase microextraction (SPME) technique. The on-rod standardization technique was applied to the PDMS rod passive sampler. Using the desorption of the pre-loaded standard on the PDMS rod to calibrate the absorption of the target analytes allows for the determination of the Time-Weighted Average (TWA) concentrations of pollutants in the aqueous media. The PDMS rod passive sampler with the on-rod standardization technique was tested in the laboratory with a flow-through system and was subsequently applied to measure TWA concentrations of polycyclic aromatic hydrocarbons (PAHs) in the field (Hamilton Harbour, Hamilton, Ont., Canada). Both the laboratory and field experiments demonstrated that, with the on-rod standardization technique, the PDMS rod can be successfully used as a passive sampler for TWA water sampling in the field. The PDMS rod passive sampler benefits from the inherent advantages of the SPME approach: it incorporates sampling, isolation and enrichment into one step. The design of this system also addressed the additional needs for passive sampling techniques, providing an economical approach to field sampling that is also easy to deploy. Rather, with this approach, TWA concentrations of target analytes can be obtained by one sampler, and can be analyzed directly, with no further sample preparation treatment required.
Gangfeng Ouyang - One of the best experts on this subject based on the ideXlab platform.
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Time-Weighted Average water sampling in Lake Ontario with solid-phase microextraction passive samplers.
Environmental science & technology, 2007Co-Authors: Gangfeng Ouyang, Wennan Zhao, Mehran Alaee, Leslie M. Bragg, Zhipei Qin, Janusz PawliszynAbstract:In this study, three types of solid-phase microextraction (SPME) passive samplers, including a fiber-retracted device, a polydimethylsiloxane (PDMS)-rod and a PDMS-membrane, were evaluated to determine the time weighted Average (TWA) concentrations of polycyclic aromatic hydrocarbons (PAHs) in Hamilton Harbor (the western tip of Lake Ontario, ON, Canada). Field trials demonstrated that these types of SPME samplers are suitable for the long-term monitoring of organic pollutants in water. These samplers possess all of the advantages of SPME: they are solvent-free, sampling, extraction and concentration are combined into one step, and they can be directly injected into a gas chromatograph (GC) for analysis without further treatment. These samplers also address the additional needs of a passive sampling technique: they are economical, easy to deploy, and the TWA concentrations of target analytes can be obtained with one sampler. Moreover, the mass uptake of these samplers is independent of the face velocity, or the effect can be calibrated, which is desirable for long-term field sampling, especially when the convection conditions of the sampling environment are difficult to measure and calibrate. Among the three types of SPME samplers that were tested, the PDMS-membrane possesses the highest surface-to-volume ratio, which results in the highest sensitivity and mass uptake and the lowest detection level.
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Time-Weighted Average water sampling with a diffusion-based solid-phase microextraction device.
Journal of chromatography. A, 2006Co-Authors: Gangfeng Ouyang, Wennan Zhao, Mehran Alaee, Janusz PawliszynAbstract:A new diffusion-based solid-phase microextraction (SPME) Time-Weighted Average (TWA) field water sampling device was developed and investigated by field trial. The sampler is constructed with copper tube and caps and a commercial SPME fiber assembly. The device possesses all advantages of SPME; it is solvent-free, reusable, combines sampling, isolation and enrichment into one step, and the fiber can be directly injected into a gas chromatograph for analysis with a commercial SPME fiber holder, without further treatment. Field trials in Laurel Creek (Waterloo, Ont., Canada) and Hamilton Harbour (Hamilton, Ont., Canada) illustrated that the device is durable, easy to deploy, and the mass uptake of the device is independent of the face velocity. The device provides good precision [relative standard deviations (RSDs) are less than 20%] and the data obtained with this device are quite comparable to those obtained with the spot sampling method, which demonstrates that the newly developed SPME water sampling device is suitable for long-term monitoring of organic pollutants in water.
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On-rod standardization technique for Time-Weighted Average water sampling with a polydimethylsiloxane rod.
Journal of chromatography. A, 2006Co-Authors: Wennan Zhao, Gangfeng Ouyang, Mehran Alaee, Janusz PawliszynAbstract:In this study, a polydimethylsiloxane (PDMS) rod was developed as a passive sampler, based on the solid-phase microextraction (SPME) technique. The on-rod standardization technique was applied to the PDMS rod passive sampler. Using the desorption of the pre-loaded standard on the PDMS rod to calibrate the absorption of the target analytes allows for the determination of the Time-Weighted Average (TWA) concentrations of pollutants in the aqueous media. The PDMS rod passive sampler with the on-rod standardization technique was tested in the laboratory with a flow-through system and was subsequently applied to measure TWA concentrations of polycyclic aromatic hydrocarbons (PAHs) in the field (Hamilton Harbour, Hamilton, Ont., Canada). Both the laboratory and field experiments demonstrated that, with the on-rod standardization technique, the PDMS rod can be successfully used as a passive sampler for TWA water sampling in the field. The PDMS rod passive sampler benefits from the inherent advantages of the SPME approach: it incorporates sampling, isolation and enrichment into one step. The design of this system also addressed the additional needs for passive sampling techniques, providing an economical approach to field sampling that is also easy to deploy. Rather, with this approach, TWA concentrations of target analytes can be obtained by one sampler, and can be analyzed directly, with no further sample preparation treatment required.
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Time-Weighted Average water sampling with a solid-phase microextraction device.
Analytical chemistry, 2005Co-Authors: Gangfeng Ouyang, Yong Chen, Janusz PawliszynAbstract:A fiber-in-needle SPME device was developed and investigated for Time-Weighted Average water sampling. The device was designed so that the overall mass-transfer resistance is contained within the static water inside the needle, which ensures that mass uptake could be predicted with Fick's first law of diffusion and the sampling rate is less affected by water turbulence. The device possesses all of the advantages of commercialized devices, in addition to needle filling and replacement ease. Laboratory calibration with deployment of the device to a flow-through system demonstrated that there was a linear mass uptake for up to 12 days, and the linear range could be longer. PDMS coating is assumed to be a perfect zero sink for most polycyclic aromatic hydrocarbons, except naphthalene. The effect of water temperature was also investigated. Under normal field conditions, the change of mass uptake rate with temperature was negligible. To facilitate the convenience for long-term water sampling, a new standard aqueous generator was introduced. This study extended the application of SPME technology for long-term water sampling.
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Time-Weighted Average passive sampling with a solid-phase microextraction device.
Analytical Chemistry, 2003Co-Authors: Gangfeng Ouyang, Yong Chen, Janusz PawliszynAbstract:A modified Solid-Phase Microextraction (SPME) device has been used as a passive sampler to determine the Time-Weighted Average (TWA) concentration of volatile organic compounds (VOCs) in air. Unlike conventional sampling with SPME, in which the fiber is extended outside its needle housing, during TWA passive sampling, the fiber is retracted a known distance into its needle housing. The SPME passive sampler collects the VOCs by the mechanism of molecular diffusion and sorption on to a coated fiber as collection medium. This process has been shown to be described by Fick's first law of diffusion, whereby determination of the amounts of analytes accumulated over time enable measurement of the TWA concentration to which the sampler was exposed. A series of fibers, 100-μm poly(dimethylsiloxane), 65-μm poly(dimethylsiloxane)/divinylbenzene, and 75-μm Carboxen/poly(dimethylsiloxane), were tested for their “zero sink”, face velocity, and response time behavior. Of the fibers tested, that coated with 75-μm Carboxe...
Yong Chen - One of the best experts on this subject based on the ideXlab platform.
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Time-Weighted Average water sampling with a solid-phase microextraction device.
Analytical chemistry, 2005Co-Authors: Gangfeng Ouyang, Yong Chen, Janusz PawliszynAbstract:A fiber-in-needle SPME device was developed and investigated for Time-Weighted Average water sampling. The device was designed so that the overall mass-transfer resistance is contained within the static water inside the needle, which ensures that mass uptake could be predicted with Fick's first law of diffusion and the sampling rate is less affected by water turbulence. The device possesses all of the advantages of commercialized devices, in addition to needle filling and replacement ease. Laboratory calibration with deployment of the device to a flow-through system demonstrated that there was a linear mass uptake for up to 12 days, and the linear range could be longer. PDMS coating is assumed to be a perfect zero sink for most polycyclic aromatic hydrocarbons, except naphthalene. The effect of water temperature was also investigated. Under normal field conditions, the change of mass uptake rate with temperature was negligible. To facilitate the convenience for long-term water sampling, a new standard aqueous generator was introduced. This study extended the application of SPME technology for long-term water sampling.
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Time-Weighted Average passive sampling with a solid-phase microextraction device.
Analytical Chemistry, 2003Co-Authors: Gangfeng Ouyang, Yong Chen, Janusz PawliszynAbstract:A modified Solid-Phase Microextraction (SPME) device has been used as a passive sampler to determine the Time-Weighted Average (TWA) concentration of volatile organic compounds (VOCs) in air. Unlike conventional sampling with SPME, in which the fiber is extended outside its needle housing, during TWA passive sampling, the fiber is retracted a known distance into its needle housing. The SPME passive sampler collects the VOCs by the mechanism of molecular diffusion and sorption on to a coated fiber as collection medium. This process has been shown to be described by Fick's first law of diffusion, whereby determination of the amounts of analytes accumulated over time enable measurement of the TWA concentration to which the sampler was exposed. A series of fibers, 100-μm poly(dimethylsiloxane), 65-μm poly(dimethylsiloxane)/divinylbenzene, and 75-μm Carboxen/poly(dimethylsiloxane), were tested for their “zero sink”, face velocity, and response time behavior. Of the fibers tested, that coated with 75-μm Carboxe...
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Time-Weighted Average passive sampling with a Solid-Phase Microextraction device
Analytical Chemistry, 2003Co-Authors: Yong Chen, Janusz PawliszynAbstract:A modified Solid-Phase Microextraction (SPME) device has been used as a passive sampler to determine the Time-Weighted Average (TWA) concentration of volatile organic compounds (VOCs) in air. Unlike conventional sampling with SPME, in which the fiber is extended outside its needle housing, during TWA passive sampling, the fiber is retracted a known distance into its needle housing. The SPME passive sampler collects the VOCs by the mechanism of molecular diffusion and sorption on to a coated fiber as collection medium. This process has been shown to be described by Fick's first law of diffusion, whereby determination of the amounts of analytes accumulated over time enable measurement of the TWA concentration to which the sampler was exposed. A series of fibers, 100-microm poly(dimethylsiloxane), 65-microm poly(dimethylsiloxane)/divinylbenzene, and 75-microm Carboxen/poly(dimethylsiloxane), were tested for their "zero sink", face velocity, and response time behavior. Of the fibers tested, that coated with 75-microm Carboxen/poly(dimethylsiloxane) was found to be an excellent passive sampler for VOCs. TWA passive sampling with a SPME device was shown to be almost independent of face velocity and to be more tolerant of high and low analyte concentrations and long and short sampling times, because of the ease with which the diffusion path length could be changed. It was found that environmental conditions, e.g., temperature, pressure, relative humidity, and ozone, have little or no effect on sampling. The 75-microm Carboxen/poly(dimethylsiloxane) fiber can retain VOCs for up to two weeks without significant loss. When the SPME device was tested in the field and the results were compared with those from National Institute of Occupational Health and Safety method 1501, good agreement was obtained.
Yilun Shang - One of the best experts on this subject based on the ideXlab platform.
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Finite-Time Weighted Average Consensus and Generalized Consensus Over a Subset
IEEE Access, 2016Co-Authors: Yilun ShangAbstract:In this paper, the finite-time consensus for arbitrary undirected graphs is discussed. We develop a parametric distributed algorithm as a function of a linear operator defined on the underlying graph and provide a necessary and sufficient condition guaranteeing weighted Average consensus in $K$ steps, where $K$ is the number of distinct eigenvalues of the underlying operator. Based on the novel framework of generalized consensus meaning that consensus is reached only by a subset of nodes, we show that the finite-time weighted Average consensus can always be reached by a subset corresponding to the non-zero variables of the eigenvector associated with a simple eigenvalue of the operator. It is interesting that the final consensus state is shown to be freely adjustable if a smaller subset of consensus is admitted. Numerical examples, including synthetic and real-world networks, are presented to illustrate the theoretical results. Our approach is inspired by the recent method of successive nulling of eigenvalues by Safavi and Khan.
Jacek A. Koziel - One of the best experts on this subject based on the ideXlab platform.
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Development of Time-Weighted Average Sampling of Odorous Volatile Organic Compounds in Air with Solid-Phase Microextraction Fiber Housed inside a GC Glass Liner: Proof of Concept.
Molecules (Basel Switzerland), 2019Co-Authors: Madina Tursumbayeva, Bulat Kenessov, Jacek A. Koziel, Devin L. Maurer, Somchai RiceAbstract:Finding farm-proven, robust sampling technologies for measurement of odorous volatile organic compounds (VOCs) and evaluating the mitigation of nuisance emissions continues to be a challenge. The objective of this research was to develop a new method for quantification of odorous VOCs in air using Time-Weighted Average (TWA) sampling. The main goal was to transform a fragile lab-based technology (i.e., solid-phase microextraction, SPME) into a rugged sampler that can be deployed for longer periods in remote locations. The developed method addresses the need to improve conventional TWA SPME that suffers from the influence of the metallic SPME needle on the sampling process. We eliminated exposure to metallic parts and replaced them with a glass tube to facilitate diffusion from odorous air onto an exposed SPME fiber. A standard gas chromatography (GC) liner recommended for SPME injections was adopted for this purpose. Acetic acid, a common odorous VOC, was selected as a model compound to prove the concept. GC with mass spectrometry (GC–MS) was used for air analysis. An SPME fiber exposed inside a glass liner followed the Fick’s law of diffusion model. There was a linear relationship between extraction time and mass extracted up to 12 h (R2 > 0.99) and the inverse of retraction depth (1/Z) (R2 > 0.99). The amount of VOC adsorbed via the TWA SPME using a GC glass liner to protect the SPME was reproducible. The limit of detection (LOD, signal-to-noise ratio (S/N) = 3) and limit of quantification (LOQ, S/N = 5) were 10 and 18 µg·m−3 (4.3 and 7.2 ppbV), respectively. There was no apparent difference relative to glass liner conditioning, offering a practical simplification for use in the field. The new method related well to field conditions when comparing it to the conventional method based on sorbent tubes. This research shows that an SPME fiber exposed inside a glass liner can be a promising, practical, simple approach for field applications to quantify odorous VOCs.
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Optimization of Time-Weighted Average Air Sampling by Solid-Phase Microextraction Fibers Using Finite Element Analysis Software
Molecules (Basel Switzerland), 2018Co-Authors: Bulat Kenessov, Jacek A. Koziel, Nassiba Baimatova, Olga P. Demyanenko, Miras DerbissalinAbstract:Determination of Time-Weighted Average (TWA) concentrations of volatile organic compounds (VOCs) in air using solid-phase microextraction (SPME) is advantageous over other sampling techniques, but is often characterized by insufficient accuracies, particularly at longer sampling times. Experimental investigation of this issue and disclosing the origin of the problem is problematic and often not practically feasible due to high uncertainties. This research is aimed at developing the model of the TWA extraction process and optimization of TWA air sampling by SPME using finite element analysis software (COMSOL Multiphysics, Burlington, MA, USA). It was established that sampling by porous SPME coatings with high affinity to analytes is affected by slow diffusion of analytes inside the coating, an increase of their concentrations in the air near the fiber tip due to equilibration, and eventual lower sampling rate. The increase of a fiber retraction depth (Z) resulted in better recoveries. Sampling of studied VOCs using 23 ga Carboxen/polydimethylsiloxane (Car/PDMS) assembly at maximum possible Z (40 mm) was proven to provide more accurate results. Alternative sampling configuration based on 78.5 × 0.75 mm internal diameter SPME liner was proven to provide similar accuracy at improved detection limits. Its modification with the decreased internal diameter from the sampling side should provide even better recoveries. The results obtained can be used to develop a more accurate analytical method for determination of TWA concentrations of VOCs in air using SPME. The developed model can be used to simulate sampling of other environments (process gases, water) by retracted SPME fibers.
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Optimization of Time-Weighted Average Air Sampling by Solid-Phase Microextraction Fibers Using Finite Element Analysis Software
2018Co-Authors: Bulat Kenessov, Jacek A. Koziel, Nassiba Baimatova, Olga P. Demyanenko, Miras DerbissalinAbstract:Determination of Time-Weighted Average (TWA) concentrations of volatile organic compounds (VOCs) in air using solid-phase microextraction (SPME) is advantageous over other sampling techniques, but is often characterized by insufficient accuracies, particularly at longer sampling times. Experimental investigation of this issue and disclosing the origin of the problem is problematic and often not practically feasible due to high uncertainties. This research is aimed at developing the model of TWA extraction process and optimization of TWA air sampling by SPME using finite element analysis software (COMSOL Multiphysics). It was established that sampling by porous SPME coatings with high affinity to analytes is affected by slow diffusion of analytes inside the coating, an increase of analytes concentrations in the air near the fiber tip due to equilibration, and eventual lower sampling rate. The increase of a fiber retraction depth (Z) resulted in better recoveries. Sampling of studied VOCs using 23-ga Car/PDMS assembly at maximum possible Z (40 mm) was proven to provide more accurate results. Alternative sampling configuration based on 78.5 x 0.75 mm i.d. SPME liner was proven to provide similar accuracy at improved detection limits. Its modification with the decreased internal diameter from the sampling side should provide even better recoveries. The developed model offers new insight into optimization of air and gas sampling using SPME.
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Analysis of trace contaminants in hot gas streams using Time-Weighted Average solid-phase microextraction: Pilot-scale validation
Fuel, 2015Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Robert C. Brown, Karl M. BroerAbstract:Abstract A new method was developed for collecting, identifying and quantifying contaminants in hot process gas streams using Time-Weighted Average (TWA) passive sampling with retracted solid-phase microextraction (SPME) and gas chromatography. The previous lab scale proof-of-concept with benzene was expanded to include the remaining major tar compounds of interest in syngas: toluene, styrene, indene, and naphthalene. The new method was tested on high T (⩾100 °C) process gas from a pilot-scale fluidized bed gasifier feeding switchgrass and compared side-by-side with conventional impingers-based method. Fourteen additional compounds were identified, representing 40–60% improvement over the conventional method’s detection capacity. Differences between the two methods were 1–20% and as much as 40–100% depending on the sampling location. Compared to the inconsistent conventional method, the SPME-TWA offered a simplified, solvent-free approach capable of drastically reducing sampling and sample preparation time and improving analytical reliability. The improved sensitivity of the new method enabled identification and quantification of VOCs beyond the capability of the conventional approaches, reaching concentrations in the ppb range (low mg/m 3 ). RSDs associated with the TWA-SPME were 3 , with successful measurement of tar concentrations at times >4000 ppm (up to 10 g/N m 3 ). The new method can be a valid alternative to the conventional method for light tar quantification under certain conditions. The opportunity also exists to exploit TWA-SPME for process gas streams analysis e.g., pyrolysis vapors and combustion exhaust.
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Analysis of trace contaminants in hot gas streams using Time-Weighted Average solid-phase microextraction: Proof of concept
Journal of chromatography. A, 2013Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Lingshuang Cai, Robert C. BrownAbstract:Abstract Time-Weighted Average (TWA) passive sampling using solid-phase microextraction (SPME) and gas chromatography was investigated as a new method of collecting, identifying and quantifying contaminants in process gas streams. Unlike previous TWA-SPME techniques using the retracted fiber configuration (fiber within needle) to monitor ambient conditions or relatively stagnant gases, this method was developed for fast-moving process gas streams at temperatures approaching 300 °C. The goal was to develop a consistent and reliable method of analyzing low concentrations of contaminants in hot gas streams without performing time-consuming exhaustive extraction with a slipstream. This work in particular aims to quantify trace tar compounds found in a syngas stream generated from biomass gasification. This paper evaluates the concept of retracted SPME at high temperatures by testing the three essential requirements for TWA passive sampling: (1) zero-sink assumption, (2) consistent and reliable response by the sampling device to changing concentrations, and (3) equal concentrations in the bulk gas stream relative to the face of the fiber syringe opening. Results indicated the method can accurately predict gas stream concentrations at elevated temperatures. Evidence was also discovered to validate the existence of a second boundary layer within the fiber during the adsorption/absorption process. This limits the technique to operating within reasonable mass loadings and loading rates, established by appropriate sampling depths and times for concentrations of interest. A limit of quantification for the benzene model tar system was estimated at 0.02 g m−3 (8 ppm) with a limit of detection of 0.5 mg m−3 (200 ppb). Using the appropriate conditions, the technique was applied to a pilot-scale fluidized-bed gasifier to verify its feasibility. Results from this test were in good agreement with literature and prior pilot plant operation, indicating the new method can measure low concentrations of tar in gasification streams.