{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T03:25:49Z","timestamp":1792121149497,"version":"4.4.0"},"reference-count":35,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2018,3,6]],"date-time":"2018-03-06T00:00:00Z","timestamp":1520294400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Analytical measurements of odorants in combination with odor threshold values is an alternative to sensory measurements that can be used to evaluate abatement technologies for pig production facilities. The purpose of the present study was to estimate odor threshold values for key odorants found in pig house air. A new method was applied where an olfactometer was used to dilute the sample air and the concentrations of odorants presented to the panelists at the dilutions steps were measured by proton-transfer-reaction mass spectrometry (PTR-MS). The results demonstrate that the odor threshold values of acetic acid, butanoic acid, and 4-methylphenol are considerably lower than reported previously, whereas the values of hydrogen sulfide, methanethiol and dimethylsulfide were comparable. Consequently, acetic acid, butanoic acid, and 4-methyl-phenol will have a larger influence on odor from pig production facilities than previously assumed. The results highlight the necessity for directly measuring exposure concentrations when determining odor threshold values.<\/jats:p>","DOI":"10.3390\/s18030788","type":"journal-article","created":{"date-parts":[[2018,3,6]],"date-time":"2018-03-06T12:16:27Z","timestamp":1520338587000},"page":"788","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Key Odorants from Pig Production Based on Improved Measurements of Odor Threshold Values Combining Olfactometry and Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9929-674X","authenticated-orcid":false,"given":"Michael","family":"Hansen","sequence":"first","affiliation":[{"name":"Department of Engineering, Aarhus University, 8000 Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pernille","family":"Kasper","sequence":"additional","affiliation":[{"name":"Department of Engineering, Aarhus University, 8000 Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anders","family":"Adamsen","sequence":"additional","affiliation":[{"name":"SEGES, 8200 Aarhus N, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5807-1336","authenticated-orcid":false,"given":"Anders","family":"Feilberg","sequence":"additional","affiliation":[{"name":"Department of Engineering, Aarhus University, 8000 Aarhus, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,3,6]]},"reference":[{"key":"ref_1","unstructured":"European Committee for Standardization (2003). Air Quality\u2014Determination of Odour Concentration by Dynamic Ofactometry, European Committee for Standardization. EN13725."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.2134\/jeq2010.0497","article-title":"Stability of odorants from pig production in sampling bags for olfactometry","volume":"40","author":"Hansen","year":"2011","journal-title":"J. Environ. Qual."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1080\/10473289.2005.10464711","article-title":"Evaluation of sample recovery of malodorous livestock gases from air sampling bags, solid-phase microextraction fibers, tenax ta sorbent tubes, and sampling canisters","volume":"55","author":"Koziel","year":"2005","journal-title":"J. Air Waste Manag. Assoc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/j.jchromb.2008.12.003","article-title":"Suitability of different polymer bags for storage of volatile sulphur compounds relevant to breath analysis","volume":"877","author":"Mochalski","year":"2009","journal-title":"J. Chromatogr. B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1668","DOI":"10.2134\/jeq2005.0370","article-title":"Bias of tedlar bags in the measurement of agricultural odorants","volume":"35","author":"Trabue","year":"2006","journal-title":"J. Environ. Qual."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"7860","DOI":"10.3390\/s130607860","article-title":"Recovery of odorants from an olfactometer measured by proton-transfer-reaction mass spectrometry","volume":"13","author":"Hansen","year":"2013","journal-title":"Sensors"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Kasper, P.L., Mannebeck, D., Oxb\u00f8l, A., Nygaard, J., Hansen, M.J., and Feilberg, A. (2017). Effects of dilution systems in olfactometry on the recovery of typical livestock odorants determined by PTR-MS. Sensors, 17.","DOI":"10.3390\/s17081859"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1103","DOI":"10.13031\/2013.13258","article-title":"Dynamic olfactometry variability in determining odor dilutions-to-threshold","volume":"42","author":"Clanton","year":"1999","journal-title":"Trans. ASAE"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.2134\/jeq2009.0184","article-title":"Evaluation of biological air filters for livestock ventilation air by membrane inlet mass spectrometry","volume":"39","author":"Feilberg","year":"2010","journal-title":"J. Environ. Qual."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"5894","DOI":"10.1021\/es100483s","article-title":"Odorant emissions from intensive pig production measured by online proton-transfer-reaction mass spectrometry","volume":"47","author":"Feilberg","year":"2010","journal-title":"Environ. Sci. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"565","DOI":"10.2134\/jeq2006.0417","article-title":"Abundances and flux estimates of volatile organic compounds from a dairy cowshed in germany","volume":"37","author":"Ngwabie","year":"2008","journal-title":"J. Environ. Qual."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1310","DOI":"10.1021\/es061475e","article-title":"Volatile organic compound emissions from dairy cows and their waste as measured by proton-transfer-reaction mass spectrometry","volume":"41","author":"Shaw","year":"2007","journal-title":"Environ. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1391","DOI":"10.1080\/10473289.2006.10464547","article-title":"Characterization of livestock odors using steel plates, solid-phase microextraction, and multidimensional gas chromatography-mass spectrometry-olfactometry","volume":"56","author":"Bulliner","year":"2006","journal-title":"J. Air Waste Manag. Assoc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"4811","DOI":"10.1016\/j.atmosenv.2007.02.012","article-title":"Sulfuric odorous compounds emitted from pig-feeding operations","volume":"41","author":"Kim","year":"2007","journal-title":"Atmos. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3745","DOI":"10.1021\/es7031407","article-title":"Field sampling method for quantifying odorants in humid environments","volume":"42","author":"Trabue","year":"2008","journal-title":"Environ. Sci. Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.atmosenv.2015.12.051","article-title":"Conversion of the chemical concentration of odorous mixtures into odour concentration and odour intensity: A comparison of methods","volume":"127","author":"Wu","year":"2016","journal-title":"Atmos. Environ."},{"key":"ref_17","first-page":"253","article-title":"Evaluation of abatement technologies for pig houses by dynamic olfactometry and on-site mass spectrometry","volume":"40","author":"Hansen","year":"2014","journal-title":"Chem. Eng. Trans."},{"key":"ref_18","unstructured":"van Gemert, L.J. (2003). Compilations of Odour Threshold Values in Air, Water and Other Media, Boelens Aroma Chemical Information Service."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"436","DOI":"10.2134\/jeq2011.0253","article-title":"Prediction of odor from pig production based on chemical odorants","volume":"41","author":"Hansen","year":"2012","journal-title":"J. Environ. Qual."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.atmosenv.2016.03.060","article-title":"Multivariate prediction of odor from pig production based on in-situ measurement of odorants","volume":"135","author":"Hansen","year":"2016","journal-title":"Atmos. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2599","DOI":"10.1021\/jf300182c","article-title":"Application of proton-transfer-reaction mass spectrometry to the assessment of odorant removal in a biological air cleaner for pig production","volume":"60","author":"Hansen","year":"2012","journal-title":"J. Agric. Food Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3786","DOI":"10.1016\/j.atmosenv.2011.04.028","article-title":"The effect of slurry treatment including ozonation on odorant reduction measured by in-situ PTR-MS","volume":"45","author":"Liu","year":"2011","journal-title":"Atmos. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.yrtph.2010.06.018","article-title":"Human chemosensory perception of methyl isothiocyanate: Chemesthesis and odor","volume":"58","author":"Cain","year":"2010","journal-title":"Regul. Toxicol. Pharmacol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6134","DOI":"10.1021\/acs.est.5b00692","article-title":"Quantitative headspace analysis of selected odorants from latrines in Africa and India","volume":"49","author":"Chappuis","year":"2015","journal-title":"Environ. Sci. Technol."},{"key":"ref_25","unstructured":"Christlbauer, M.R. (2006). Evaluation of Odours from Agricultural Sources by Methods of Molecular Sensory. [Ph.D. Thesis, Deuthche Forschungsanstalt f\u00fcr Lebensmittelchemie]."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1007\/s00221-010-2430-0","article-title":"Structure-activity relationships on the odor detectability of homologous carboxylic acids by humans","volume":"207","author":"Abraham","year":"2010","journal-title":"Exp. Brain Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"9895","DOI":"10.1021\/jf901453r","article-title":"Odor detection of mixtures of homologous carboxylic acids and coffee aroma compounds by humans","volume":"57","author":"Miyazawa","year":"2009","journal-title":"J. Agric. Food Chem."},{"key":"ref_28","unstructured":"Nagata, Y. (2003). Measurement of odor threshold by triangle odor bag method, Odor Measurement Review."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1093\/chemse\/bjm016","article-title":"Human odor detection of homologous carboxylic acids and their binary mixtures","volume":"32","author":"Wise","year":"2007","journal-title":"Chem. Senses"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.atmosenv.2013.12.032","article-title":"Odor measurements according to en 13725: A statistical analysis of variance components","volume":"86","author":"Klarenbeek","year":"2014","journal-title":"Atmos. Environ."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1093\/chemse\/bjr009","article-title":"The influence of molecular structure on odor qualities and odor detection thresholds of volatile alkylated phenols","volume":"36","author":"Czerny","year":"2011","journal-title":"Chem. Senses"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1093\/chemse\/7.3-4.215","article-title":"Measurement of human olfactory thresholds for several groups of structurally related compounds","volume":"7","author":"Punter","year":"1983","journal-title":"Chem. Senses"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1093\/chemse\/2.3.267","article-title":"Specific anosmia and the concept of primary odors","volume":"2","author":"Amoore","year":"1977","journal-title":"Chem. Senses"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1177\/154405910408300116","article-title":"Study on the organoleptic intensity scale for measuring oral malodor","volume":"83","author":"Greenman","year":"2004","journal-title":"J. Dent. Res."},{"key":"ref_35","unstructured":"Van Langenhove, H., and Schamp, N. (1984, January 25\u201327). Chemical and olfactometric measurement of odours. Proceedings of the International Symposium Characterization and Control of Odoriferous Pollutants in Process Industries, Louvain-La-Neuve, Belgium."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/788\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:57:39Z","timestamp":1760194659000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/3\/788"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,3,6]]},"references-count":35,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2018,3]]}},"alternative-id":["s18030788"],"URL":"https:\/\/doi.org\/10.3390\/s18030788","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,3,6]]}}}