{"title":"利用 5A 分子筛色谱柱改进含高碳氮比有机材料中氮稳定同位素的测量方法","authors":"","doi":"10.1016/j.mex.2024.102889","DOIUrl":null,"url":null,"abstract":"<div><p>The nitrogen stable isotope composition (δ<sup>15</sup>N) of plant materials has numerous applications. Plant materials like bark can have a very high C:N ratio. Incomplete C combustion in such samples interferes with the δ<sup>15</sup>N measurement due to CO production. We modified the standard setup for δ<sup>15</sup>N measurement using an elemental analyzer (EA) coupled to an isotope ratio mass spectrometer (IRMS) by incorporating a 5A molecular sieve column, which better separates N<sub>2</sub> from CO. We compared this new modified setup and the standard one for the measurement of bark samples. Precision and accuracy for δ<sup>15</sup>N in standards with low C:N ratio were equivalent for the two methods. However, for bark the results obtained with the new method had better precision and accuracy than the standard method. <strong>Replicates are nevertheless recommended with the new method to ensure confidence in the results.</strong></p><ul><li><span>•</span><span><p>During elemental analysis, incomplete combustion of material with high C:N ratio can lead to CO formation, which interferes with δ<sup>15</sup>N IRMS measurements.</p></span></li><li><span>•</span><span><p>Here we use a 5A molsieve column to remove the CO interference in δ<sup>15</sup>N measurements Precision and accuracy on δ<sup>15</sup>N measurements of samples with high C content are significantly improved</p></span></li></ul></div>","PeriodicalId":18446,"journal":{"name":"MethodsX","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2215016124003418/pdfft?md5=b26da25765ee88c19104b645709e0b9f&pid=1-s2.0-S2215016124003418-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Improving the measurement of nitrogen stable isotopes in organic materials containing high C:N ratios using a 5A molecular sieve column\",\"authors\":\"\",\"doi\":\"10.1016/j.mex.2024.102889\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The nitrogen stable isotope composition (δ<sup>15</sup>N) of plant materials has numerous applications. Plant materials like bark can have a very high C:N ratio. Incomplete C combustion in such samples interferes with the δ<sup>15</sup>N measurement due to CO production. We modified the standard setup for δ<sup>15</sup>N measurement using an elemental analyzer (EA) coupled to an isotope ratio mass spectrometer (IRMS) by incorporating a 5A molecular sieve column, which better separates N<sub>2</sub> from CO. We compared this new modified setup and the standard one for the measurement of bark samples. Precision and accuracy for δ<sup>15</sup>N in standards with low C:N ratio were equivalent for the two methods. However, for bark the results obtained with the new method had better precision and accuracy than the standard method. <strong>Replicates are nevertheless recommended with the new method to ensure confidence in the results.</strong></p><ul><li><span>•</span><span><p>During elemental analysis, incomplete combustion of material with high C:N ratio can lead to CO formation, which interferes with δ<sup>15</sup>N IRMS measurements.</p></span></li><li><span>•</span><span><p>Here we use a 5A molsieve column to remove the CO interference in δ<sup>15</sup>N measurements Precision and accuracy on δ<sup>15</sup>N measurements of samples with high C content are significantly improved</p></span></li></ul></div>\",\"PeriodicalId\":18446,\"journal\":{\"name\":\"MethodsX\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2024-08-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2215016124003418/pdfft?md5=b26da25765ee88c19104b645709e0b9f&pid=1-s2.0-S2215016124003418-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"MethodsX\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2215016124003418\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MULTIDISCIPLINARY SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"MethodsX","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2215016124003418","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
摘要
植物材料的氮稳定同位素组成(δ15N)有许多用途。树皮等植物材料的碳氮比可能非常高。由于 CO 的产生,此类样本中不完全燃烧的 C 会干扰 δ15N 的测量。我们对使用元素分析仪(EA)和同位素比质谱仪(IRMS)测量δ15N 的标准装置进行了改进,加入了 5A 分子筛色谱柱,它能更好地分离 N2 和 CO。我们比较了这种新的改进装置和标准装置对树皮样品的测量结果。对于 C:N 比值较低的标准样品中的δ15N,两种方法的精度和准确度相当。然而,对于树皮,新方法获得的结果比标准方法的精度和准确度更高。在元素分析过程中,高 C:N 比值物质的不完全燃烧会导致 CO 的形成,从而干扰 δ15N IRMS 测量。
Improving the measurement of nitrogen stable isotopes in organic materials containing high C:N ratios using a 5A molecular sieve column
The nitrogen stable isotope composition (δ15N) of plant materials has numerous applications. Plant materials like bark can have a very high C:N ratio. Incomplete C combustion in such samples interferes with the δ15N measurement due to CO production. We modified the standard setup for δ15N measurement using an elemental analyzer (EA) coupled to an isotope ratio mass spectrometer (IRMS) by incorporating a 5A molecular sieve column, which better separates N2 from CO. We compared this new modified setup and the standard one for the measurement of bark samples. Precision and accuracy for δ15N in standards with low C:N ratio were equivalent for the two methods. However, for bark the results obtained with the new method had better precision and accuracy than the standard method. Replicates are nevertheless recommended with the new method to ensure confidence in the results.
•
During elemental analysis, incomplete combustion of material with high C:N ratio can lead to CO formation, which interferes with δ15N IRMS measurements.
•
Here we use a 5A molsieve column to remove the CO interference in δ15N measurements Precision and accuracy on δ15N measurements of samples with high C content are significantly improved