@article{
 title = {Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations},
 type = {article},
 year = {2004},
 pages = {27-48},
 volume = {38},
 id = {9cd761df-6b0c-3b76-95a1-4673d0fe90ad},
 created = {2014-10-08T16:28:18.000Z},
 file_attached = {false},
 profile_id = {363623ef-1990-38f1-b354-f5cdaa6548b2},
 group_id = {02267cec-5558-3876-9cfc-78d056bad5b9},
 last_modified = {2017-03-14T17:32:24.802Z},
 read = {false},
 starred = {false},
 authored = {false},
 confirmed = {true},
 hidden = {false},
 citation_key = {Subramanian:AST:2004a},
 source_type = {article},
 private_publication = {false},
 abstract = {Measurement of ambient particulate organic carbon
(POC) with quartz filters is prone to positive and negative
sampling artifacts. One approach for estimating these artifacts is
to sample with a backup quartz filter placed behind either the main
quartz filter or a Teflon filter in a parallel line. Another
approach is to use a denuder to reduce the positive artifact in
combination with a highly adsorbent backup filter to capture any
negative artifact. Results obtained using both of these approaches
in parallel for over one year in Pittsburgh, PA are presented in
this article. A sampler using an activated carbon monolith denuder
has been developed and tested extensively. Transmission losses were
found to be negligible, and the denuder is on average 94%
efficient at removing gas-phase organics. Denuder breakthrough is
corrected for each run using a dynamic blank in parallel with the
sample line. Comparisons with the dynamic blank indicate that the
denuder almost eliminates the positive artifact on the quartz
filter. Negative artifact from the denuded quartz filter is
quantified using a carbon-impregnated glass fiber (CIG) backup
filter and was found to be small, typically less than 10% of the
ambient POC. Compared to the denuded sampler POC, 24 h bare quartz
samples showed an almost constant positive artifact of 0.5
mug-C/m(3) for samples taken throughout the year-long study period.
Sampling for shorter durations (4-6 h) resulted in a larger
positive artifact. A quartz filter behind a Teflon filter (QBT)
provides a consistent estimate of the positive artifact on the bare
quartz filter irrespective of sample duration, though it
overcorrects for the positive artifact by 16-20% (attributed to
particulate matter volatilizing off the upstream Teflon filter).
The quartz behind quartz (QBQ) approach provides a reasonable
estimate of the positive artifact on the bare quartz filter for the
24 h samples but not for the shorter samples. A slight seasonal
variation is observed in the absolute value of the positive
artifact, with higher values observed during the summer months.
C1 Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA.
Duke Univ, Dept Civil & Environm Engn, Durham, NC 27706 USA. MIT,
Cambridge, MA 02139 USA.
},
 bibtype = {article},
 author = {Subramanian, R and Khlystov, A Y and Cabada, J C and Robinson, A L},
 journal = {Aerosol Sci. Technol.}
}

{"_id":{"_str":"5411bfbb480d3bb058002a9b"},"__v":0,"authorIDs":[],"author_short":["Subramanian, R.","Khlystov, A., Y.","Cabada, J., C.","Robinson, A., L."],"bibbaseid":"subramanian-khlystov-cabada-robinson-positiveandnegativeartifactsinparticulateorganiccarbonmeasurementswithdenudedandundenudedsamplerconfigurations-2004","bibdata":{"title":"Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations","type":"article","year":"2004","pages":"27-48","volume":"38","id":"9cd761df-6b0c-3b76-95a1-4673d0fe90ad","created":"2014-10-08T16:28:18.000Z","file_attached":false,"profile_id":"363623ef-1990-38f1-b354-f5cdaa6548b2","group_id":"02267cec-5558-3876-9cfc-78d056bad5b9","last_modified":"2017-03-14T17:32:24.802Z","read":false,"starred":false,"authored":false,"confirmed":"true","hidden":false,"citation_key":"Subramanian:AST:2004a","source_type":"article","private_publication":false,"abstract":"Measurement of ambient particulate organic carbon\n(POC) with quartz filters is prone to positive and negative\nsampling artifacts. One approach for estimating these artifacts is\nto sample with a backup quartz filter placed behind either the main\nquartz filter or a Teflon filter in a parallel line. Another\napproach is to use a denuder to reduce the positive artifact in\ncombination with a highly adsorbent backup filter to capture any\nnegative artifact. Results obtained using both of these approaches\nin parallel for over one year in Pittsburgh, PA are presented in\nthis article. A sampler using an activated carbon monolith denuder\nhas been developed and tested extensively. Transmission losses were\nfound to be negligible, and the denuder is on average 94%\nefficient at removing gas-phase organics. Denuder breakthrough is\ncorrected for each run using a dynamic blank in parallel with the\nsample line. Comparisons with the dynamic blank indicate that the\ndenuder almost eliminates the positive artifact on the quartz\nfilter. Negative artifact from the denuded quartz filter is\nquantified using a carbon-impregnated glass fiber (CIG) backup\nfilter and was found to be small, typically less than 10% of the\nambient POC. Compared to the denuded sampler POC, 24 h bare quartz\nsamples showed an almost constant positive artifact of 0.5\nmug-C/m(3) for samples taken throughout the year-long study period.\nSampling for shorter durations (4-6 h) resulted in a larger\npositive artifact. A quartz filter behind a Teflon filter (QBT)\nprovides a consistent estimate of the positive artifact on the bare\nquartz filter irrespective of sample duration, though it\novercorrects for the positive artifact by 16-20% (attributed to\nparticulate matter volatilizing off the upstream Teflon filter).\nThe quartz behind quartz (QBQ) approach provides a reasonable\nestimate of the positive artifact on the bare quartz filter for the\n24 h samples but not for the shorter samples. A slight seasonal\nvariation is observed in the absolute value of the positive\nartifact, with higher values observed during the summer months.\nC1 Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA.\nDuke Univ, Dept Civil & Environm Engn, Durham, NC 27706 USA. MIT,\nCambridge, MA 02139 USA.\n","bibtype":"article","author":"Subramanian, R and Khlystov, A Y and Cabada, J C and Robinson, A L","journal":"Aerosol Sci. Technol.","bibtex":"@article{\n title = {Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations},\n type = {article},\n year = {2004},\n pages = {27-48},\n volume = {38},\n id = {9cd761df-6b0c-3b76-95a1-4673d0fe90ad},\n created = {2014-10-08T16:28:18.000Z},\n file_attached = {false},\n profile_id = {363623ef-1990-38f1-b354-f5cdaa6548b2},\n group_id = {02267cec-5558-3876-9cfc-78d056bad5b9},\n last_modified = {2017-03-14T17:32:24.802Z},\n read = {false},\n starred = {false},\n authored = {false},\n confirmed = {true},\n hidden = {false},\n citation_key = {Subramanian:AST:2004a},\n source_type = {article},\n private_publication = {false},\n abstract = {Measurement of ambient particulate organic carbon\n(POC) with quartz filters is prone to positive and negative\nsampling artifacts. One approach for estimating these artifacts is\nto sample with a backup quartz filter placed behind either the main\nquartz filter or a Teflon filter in a parallel line. Another\napproach is to use a denuder to reduce the positive artifact in\ncombination with a highly adsorbent backup filter to capture any\nnegative artifact. Results obtained using both of these approaches\nin parallel for over one year in Pittsburgh, PA are presented in\nthis article. A sampler using an activated carbon monolith denuder\nhas been developed and tested extensively. Transmission losses were\nfound to be negligible, and the denuder is on average 94%\nefficient at removing gas-phase organics. Denuder breakthrough is\ncorrected for each run using a dynamic blank in parallel with the\nsample line. Comparisons with the dynamic blank indicate that the\ndenuder almost eliminates the positive artifact on the quartz\nfilter. Negative artifact from the denuded quartz filter is\nquantified using a carbon-impregnated glass fiber (CIG) backup\nfilter and was found to be small, typically less than 10% of the\nambient POC. Compared to the denuded sampler POC, 24 h bare quartz\nsamples showed an almost constant positive artifact of 0.5\nmug-C/m(3) for samples taken throughout the year-long study period.\nSampling for shorter durations (4-6 h) resulted in a larger\npositive artifact. A quartz filter behind a Teflon filter (QBT)\nprovides a consistent estimate of the positive artifact on the bare\nquartz filter irrespective of sample duration, though it\novercorrects for the positive artifact by 16-20% (attributed to\nparticulate matter volatilizing off the upstream Teflon filter).\nThe quartz behind quartz (QBQ) approach provides a reasonable\nestimate of the positive artifact on the bare quartz filter for the\n24 h samples but not for the shorter samples. A slight seasonal\nvariation is observed in the absolute value of the positive\nartifact, with higher values observed during the summer months.\nC1 Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA.\nDuke Univ, Dept Civil & Environm Engn, Durham, NC 27706 USA. MIT,\nCambridge, MA 02139 USA.\n},\n bibtype = {article},\n author = {Subramanian, R and Khlystov, A Y and Cabada, J C and Robinson, A L},\n journal = {Aerosol Sci. Technol.}\n}","author_short":["Subramanian, R.","Khlystov, A., Y.","Cabada, J., C.","Robinson, A., L."],"bibbaseid":"subramanian-khlystov-cabada-robinson-positiveandnegativeartifactsinparticulateorganiccarbonmeasurementswithdenudedandundenudedsamplerconfigurations-2004","role":"author","urls":{},"downloads":0},"bibtype":"article","biburl":null,"creationDate":"2014-09-11T15:28:59.274Z","downloads":0,"keywords":[],"search_terms":["positive","negative","artifacts","particulate","organic","carbon","measurements","denuded","undenuded","sampler","configurations","subramanian","khlystov","cabada","robinson"],"title":"Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations","year":2004}