{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T12:17:03Z","timestamp":1791980223844,"version":"4.4.0"},"reference-count":35,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2008,1,8]],"date-time":"2008-01-08T00:00:00Z","timestamp":1199750400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Rapid Comm Mass Spectrometry"],"published-print":{"date-parts":[[2008,2,15]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    We present a method for high\u2010sensitivity nitrogen isotopic analysis of particulate organic nitrogen (PON) in seawater and freshwater, for the purpose of determining the aquatic nitrogen fixation rate through the\n                    <jats:sup>15<\/jats:sup>\n                    N\n                    <jats:sub>2<\/jats:sub>\n                    tracer technique for samples that contain a low abundance of organisms. The method is composed of the traditional oxidation\/reduction methods, such as the oxidation of PON to nitrate (NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-1.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-1\"\/>\n                    ) using persulfate, the reduction of NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-2.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-2\"\/>\n                    to nitrite (NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-3.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-3\"\/>\n                    ) using spongy cadmium, and further reduction of NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-4.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-4\"\/>\n                    to nitrous oxide (N\n                    <jats:sub>2<\/jats:sub>\n                    O) using sodium azide. Then, N\n                    <jats:sub>2<\/jats:sub>\n                    O is purged from the water and trapped cryogenically with subsequent release into a gas chromatography column to analyze the stable nitrogen isotopic composition using continuous\u2010flow isotope ratio mass spectrometry (CF\u2010IRMS) by simultaneously monitoring the NO\n                    <jats:sup>+<\/jats:sup>\n                    ion currents at masses 30, 31, and 32. The nitrogen isotopic fractionation was consistent within each batch of analysis. The standard deviation of sample measurements was less than 0.3\u2030 for samples containing PON of more than 50\u2009nmolN, and 0.5\u2030 for those of more than 20\u2009nmolN, by subtracting the contribution of blank nitrogen, 8\u2009\u00b1\u20092\u2009nmol at final N\n                    <jats:sub>2<\/jats:sub>\n                    O. By using this method, we can determine\n                    <jats:italic>\u03b4<\/jats:italic>\n                    <jats:sup>15<\/jats:sup>\n                    N for lower quantities of PON better than by other methods, so we can reduce the quantities of water samples needed for incubation to determine the nitrogen fixation rate. In addition, we can expand the method to determine the nitrogen isotopic composition of organic nitrogen in general, such as that of total dissolved nitrogen (TDN; sum of NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-5.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-5\"\/>\n                    , NO\n                    <jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"graphic\/tex2gif-stack-6.gif\" xlink:title=\"urn:x-wiley:09514198:media:RCM3368:tex2gif-stack-6\"\/>\n                    , ammonium, and DON), by applying the method to filtrates. Copyright \u00a9 2008 John Wiley &amp; Sons, Ltd.\n                  <\/jats:p>","DOI":"10.1002\/rcm.3368","type":"journal-article","created":{"date-parts":[[2008,1,8]],"date-time":"2008-01-08T06:56:56Z","timestamp":1199775416000},"page":"345-354","source":"Crossref","is-referenced-by-count":52,"title":["Sensitive determinations of stable nitrogen isotopic composition of organic nitrogen through chemical conversion into N\n                    <sub>2<\/sub>\n                    O"],"prefix":"10.1002","volume":"22","author":[{"given":"Urumu","family":"Tsunogai","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tadasuke","family":"Kido","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akinari","family":"Hirota","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satoru B.","family":"Ohkubo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daisuke D.","family":"Komatsu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumiko","family":"Nakagawa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2008,1,10]]},"reference":[{"key":"e_1_2_5_2_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature02824"},{"key":"e_1_2_5_3_2","first-page":"65","volume-title":"Methods for Evaluating Biological Nitrogen Fixation","author":"Bergerson FJ","year":"1980"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1104\/pp.43.8.1185"},{"key":"e_1_2_5_5_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.58.5.2071"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.4319\/lo.1977.22.1.0060"},{"key":"e_1_2_5_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/0003-2697(76)90187-1"},{"key":"e_1_2_5_8_2","doi-asserted-by":"publisher","DOI":"10.1139\/f80-063"},{"key":"e_1_2_5_9_2","doi-asserted-by":"crossref","first-page":"986","DOI":"10.1128\/aem.62.3.986-993.1996","volume":"62","author":"Montoya JP","year":"1996","journal-title":"Appl. Environ. Microbiol."},{"key":"e_1_2_5_10_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0231(19990715)13:13<1237::AID-RCM633>3.0.CO;2-C"},{"key":"e_1_2_5_11_2","doi-asserted-by":"publisher","DOI":"10.1017\/S0025315405012580"},{"key":"e_1_2_5_12_2","volume-title":"Finnigan MAT Application Flash Report, G29","author":"Avak H","year":"1999"},{"key":"e_1_2_5_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/rcm.2847"},{"key":"e_1_2_5_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0012-821X(98)00075-2"},{"key":"e_1_2_5_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0016-7037(00)00374-4"},{"key":"e_1_2_5_16_2","doi-asserted-by":"publisher","DOI":"10.1002\/1097-0231(20000830)14:16<1507::AID-RCM56>3.0.CO;2-E"},{"key":"e_1_2_5_17_2","doi-asserted-by":"publisher","DOI":"10.1029\/2001GL014311"},{"key":"e_1_2_5_18_2","doi-asserted-by":"publisher","DOI":"10.1021\/ac050528s"},{"key":"e_1_2_5_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/0304-4203(81)90027-X"},{"key":"e_1_2_5_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/ac020113w"},{"key":"e_1_2_5_21_2","doi-asserted-by":"publisher","DOI":"10.1029\/2003PA000996"},{"key":"e_1_2_5_22_2","doi-asserted-by":"publisher","DOI":"10.1029\/2004PA001114"},{"key":"e_1_2_5_23_2","doi-asserted-by":"publisher","DOI":"10.1029\/2004GB002320"},{"key":"e_1_2_5_24_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0510185103"},{"key":"e_1_2_5_25_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0609935104"},{"key":"e_1_2_5_26_2","doi-asserted-by":"publisher","DOI":"10.1002\/hlca.19550380722"},{"key":"e_1_2_5_27_2","doi-asserted-by":"publisher","DOI":"10.1021\/ac9904563"},{"key":"e_1_2_5_28_2","doi-asserted-by":"publisher","DOI":"10.4319\/lo.1991.36.2.0405"},{"key":"e_1_2_5_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chroma.2005.05.073"},{"key":"e_1_2_5_30_2","doi-asserted-by":"publisher","DOI":"10.2116\/bunsekikagaku.52.319"},{"key":"e_1_2_5_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2005.05.042"},{"key":"e_1_2_5_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/0146-6380(94)90002-7"},{"key":"e_1_2_5_33_2","doi-asserted-by":"publisher","DOI":"10.1002\/rcm.1081"},{"key":"e_1_2_5_34_2","first-page":"51","volume-title":"Reference and Intercomparison Materials for Stable Isotopes of Light Elements","author":"B\u00f6hlke JK","year":"1995"},{"key":"e_1_2_5_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/0883-2889(89)90100-7"},{"key":"e_1_2_5_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/ac061598h"}],"container-title":["Rapid Communications in Mass Spectrometry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Frcm.3368","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/rcm.3368","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T11:05:12Z","timestamp":1761476712000},"score":1,"resource":{"primary":{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/10.1002\/rcm.3368"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,1,10]]},"references-count":35,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2008,2,15]]}},"alternative-id":["10.1002\/rcm.3368"],"URL":"https:\/\/doi.org\/10.1002\/rcm.3368","archive":["Portico"],"relation":{},"ISSN":["0951-4198","1097-0231"],"issn-type":[{"value":"0951-4198","type":"print"},{"value":"1097-0231","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,1,10]]}}}