{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T21:27:19Z","timestamp":1775856439862,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2020,7,21]],"date-time":"2020-07-21T00:00:00Z","timestamp":1595289600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Korea Ministry of Education","award":["2019R1A6A3A03033990"],"award-info":[{"award-number":["2019R1A6A3A03033990"]}]},{"name":"The Korea Ministry of Education","award":["2018R1A6A1A03024940"],"award-info":[{"award-number":["2018R1A6A1A03024940"]}]},{"name":"The Korea Ministry of Environment","award":["2018002490001"],"award-info":[{"award-number":["2018002490001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The use of humidifier disinfectant (HD) has been determined to be associated with lung injuries (HDLI) in Korea. Although HD brands containing polyhexamethylene guanidine (PHMG) oligomers have been found to cause more HDLI compared to brands containing other disinfectants, the physicochemical properties of PHMG have been poorly defined. We aimed to quantify the PHMG dissolved in HD brands, characterize the number-average (Mn) and weight-average (Mw) molecular masses, and identify the polymerization degree of PHMG. Analysis of the PHMG oligomers was performed using a matrix-assisted laser desorption\/ionization time-of-flight mass spectrometer (MALDI-TOF MS) operated in positive-ion reflectron mode. Eight brands of HD containing PHMG were identified. The PHMG concentrations in these brands ranged from 160 to 37,200 ppm (mean = 3100.9 ppm). Concentration was a significant variable among and within HD brands. The degree of PHMG oligomerization fell within the range of two to four. The averages of Mn and Mw were 517.2 g\/mol (range: 422\u2013613 g\/mol) and 537.3 g\/mol (range: 441.0\u2013678.0 g\/mol), respectively. Based on the average molecular weight and the degree of polymerization, the PHMG examined here could be regarded as oligomers, which may be associated with the highest proportion of HDLI being caused by PHMG.<\/jats:p>","DOI":"10.3390\/molecules25143301","type":"journal-article","created":{"date-parts":[[2020,7,22]],"date-time":"2020-07-22T07:31:28Z","timestamp":1595403088000},"page":"3301","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":37,"title":["Properties of Polyhexamethylene Guanidine (PHMG) Associated with Fatal Lung Injury in Korea"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3847-7392","authenticated-orcid":false,"given":"Dong-Uk","family":"Park","sequence":"first","affiliation":[{"name":"Department of Environmental Health, Korea National Open University, Seoul 03087, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4829-5587","authenticated-orcid":false,"given":"Jihoon","family":"Park","sequence":"additional","affiliation":[{"name":"Environmental Safety Group, Korea Institute of Science and Technology Europe Forschungsgesellschaft mbH, 66123 Saarbr\u00fccken, Germany"},{"name":"Institute of Health and Environment, Graduate School of Public Health, Seoul National University, Seoul 08826, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kee Won","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Sogang University, Seoul 04107, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ju-Hyun","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Statistics, Dongguk University, Seoul 04620, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6341-7562","authenticated-orcid":false,"given":"Jung-Hwan","family":"Kwon","sequence":"additional","affiliation":[{"name":"Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Han Bin","family":"Oh","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Sogang University, Seoul 04107, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Yang, H.J., Kim, H.J., Yu, J., Lee, E., Jung, Y.H., Kim, H.Y., Seo, J.H., Kwon, G.Y., Park, J.H., and Gwack, J. 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