Vapor adsorption artifact in the sampling of organic aerosol: Face velocity effects

McDow, Stephen R.; Huntzicker, James J.

doi:10.1016/0960-1686(90)90134-9

Cited by 279 publications

(201 citation statements)

References 26 publications

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“…It is possible that a high enough pressure drop could develop across a heavily loaded filter to induce volatile losses of collected organic material (negative artifact). This artifact is difficult to measure, but experiments and calculations suggest that pressure-drop induced volatile losses are negligible for sampling conditions similar to the current study and other typical indoor studies (i.e., no denuder and low face velocity) (McDow and Huntzicker, 1990). In addition, changes in temperature and in organic vapor concentrations during sampling can disturb the equilibrium between the gas-phase passing through the filter and the organic material sorbed to the filter and particles.…”

Section: Introductionmentioning

confidence: 50%

Fine organic particulate matter dominates indoor-generated PM2.5 in RIOPA homes

Polidori

Turpin

Meng

et al. 2006

J Expo Sci Environ Epidemiol

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Residential indoor and outdoor fine particle (PM 2.5 ) organic (OC) and elemental carbon (EC) concentrations (48 h) were measured at 173 homes in Houston, TX, Los Angeles County, CA, and Elizabeth, NJ as part of the Relationship of Indoor, Outdoor and Personal Air (RIOPA) study. The adsorption of organic vapors on the quartz fiber sampling filter (a positive artifact) was substantial indoors and out, accounting for 36% and 37% of measured OC at the median indoor (8.2 mg C/m 3 ) and outdoor (5.0 mg C/m 3 ) OC concentrations, respectively. Uncorrected, adsorption artifacts would lead to substantial overestimation of particulate OC both indoors and outdoors. After artifact correction, the mean particulate organic matter (OM ¼ 1.4 OC) concentration indoors (9.8 mg/m 3 ) was twice the mean outdoor concentration (4.9 mg/m 3 ). The mean EC concentration was 1.1 mg/m 3 both indoors and outdoors. OM accounted for 29%, 30% and 29% of PM 2.5 mass outdoors and 48%, 55% and 61% of indoor PM 2.5 mass in Los Angeles Co., Elizabeth and Houston study homes, respectively. Indirect evidence provided by species mass balance results suggests that PM 2.5 nitrate (not measured) was largely lost during outdoor-to-indoor transport, as reported by Lunden et al. This results in dramatic changes with outdoor-to-indoor transport in the mass and composition of ambient-generated PM 2.5 at California homes. On average, 71% to 76% of indoor OM was emitted or formed indoors, calculated by (1) Random Component Superposition (RCS) model and (2) non-linear fit of OC and air exchange rate data to the mass balance model. Assuming that all particles penetrate indoors (P ¼ 1) and there is no particle loss indoors (k ¼ 0), a lower bound estimate of 41% of indoor OM was indoor-generated (mean). OM appears to be the predominant species in indoor-generated PM 2.5 , based on species mass balance results. Particulate OM emitted or formed indoors is substantial enough to alter the concentration, composition and behavior of indoor PM 2.5 . One interesting effect of increased indoor OM concentrations is a shift in the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs) from the gas to the particle phase with outdoor-to-indoor transport.

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Section: Introductionmentioning

confidence: 50%

Fine organic particulate matter dominates indoor-generated PM2.5 in RIOPA homes

Polidori

Turpin

Meng

et al. 2006

J Expo Sci Environ Epidemiol

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“…High, net positive, sampling artifacts have been observed during indoor particulate organic carbon (OC) sampling using quartz filters (14)(15). It is not yet known whether a similar, net positive, sampling artifact occurs during the measurement of personal exposure to particulate organic carbon; however, one is expected because positive artifacts have been observed in both outdoor and indoor sampling (5)(6)(7)(8)14,15). Such measurement artifacts hinder not only the characterization of indoor and personal exposures to various constituents of PM but also the source apportionment efforts in identifying sources that contribute to personal PM exposures and health effects.…”

Section: Introductionmentioning

confidence: 99%

Development and Evaluation of a Personal Particulate Organic and Mass Sampler

Pang

Gundel

Larson

et al. 2002

Environ. Sci. Technol.

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Accurate measurement of personal exposure to particulate matter and its constituents requires samplers that are accurate, compact, lightweight, inexpensive, and convenient to use. The Personal Particulate Organic and Mass Sampler (PPOMS) has been developed to meet these criteria. The PPOMS uses activated carbon-impregnated foam as a combined 2.5-µm size-selective inlet and denuder for assessment of fine particle mass and organic carbon. Proof of the PPOMS concept has been established by comparing mass and organic carbon in particles collected with collocated samplers in Seattle, at a central outdoor site, and in residences. Daily particulate mass concentrations averaged 10.0±5.2, 12.0±5.3, and 11.2±5.1 µg m -3 for the Federal Reference Method, the Harvard Personal Exposure Monitor, and the PPOMS, respectively, for 10 24-h sampling periods. During a series of PM 2.5 indoor organic carbon (OC) measurements from single quartz filters, the apparent indoor OC averaged 7.7±0.8 µg of C m -3 , which was close to the indoor PM 2.5 mass from collocated Teflon filters (7.3±2.3 µg of C m -3 ), indicating the presence of a large positive OC artifact. In collocated measurements, the PPOMS eliminated this artifact just as well as the Integrated Gas and Particle Sampler that incorporated a macroreticular polystyrene-divinylbenzene (XAD-4) resin-coated denuder, yielding OC concentrations of 2.5 ± 0.4 and 2.4 ± 1.0 µg C m -3 , respectively. Thermal analysis for OC indicated that the indoor positive artifact was due to adsorption of gas-phase semivolatile organic compounds SVOC. This study shows that the PPOMS design provides a 2.5-µm size-selective inlet that also prevents the adsorption of gas-phase SVOC onto quartz filters, thus eliminating the filter positive artifact. The PPOMS meets a significant current challenge for indoor and personal sampling of particulate organic carbon. The PPOMS design can also simplify accurate ambient sampling for PM 2.5 .

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“…For example, issues associated with sampling OC on QFFs include adsorption and absorption on both collected particles and quartz-fiber filter material (positive sampling artifacts) and may occur passively during storage, transport, and handling or actively during sampling. Conversely, volatilization of semivolatile organic compounds (SVOC) from collected particles (negative sampling artifacts) can occur during sampling with a likely dependence on flow rate or pressure drop, temperature, and RH (McDow and Huntzicker, 1990). Negative artifact also can occur throughout the transport and storage processes after collection.…”

Section: Artifact and Blank Correctionsmentioning

confidence: 99%

“…However, while heat treating removes the initial OC artifact, QFF medium continues to sorb organic gases until reaching pseudo-equilibrium. The overall artifact is both passive and active and depends on the sampled volume and several other factors and can reach the equivalent of 4 mg/m 3 for CSN filters sampled with the MetOne sampler (McDow and Huntzicker, 1990;EPA, 1998;Solomon et al, 2000;Turpin et al, 1994;Turpin et al, 2000;Maimone et al, 2011).…”

Section: Acceptance Testingmentioning

confidence: 99%