Integrative assessment for amino acid nitrogen isotopic composition in biological tissue samples determined by GC/C/IRMS, LC x EA/IRMS, and LC x GC/C/IRMS.
Integrative assessment for amino acid nitrogen isotopic composition in biological tissue samples determined by GC/C/IRMS, LC x EA/IRMS, and LC x GC/C/IRMS.
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通过 GC/C/IRMS、LC x EA/IRMS 和 LC x GC/C/IRMS 测定生物组织样品中氨基酸氮同位素组成的综合评估。
DOI：
10.1002/lom3.10502
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
N.
中科院分区：
文献类型：
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作者：
Ishikawa;N. F.;Ogawa;N. O.;Sun;Y.;Chikaraishi;Y.;Takano;Y.;and Ohkouchi;N.
氨基酸中氮（δ15N）的化合物特异性同位素分析（CSIA‐AA）对人类学、生物地球化学和生态学等环境科学做出了重大贡献。测定氨基酸(AAs) δ15N的方法有几种。尽管这些方法各有优缺点，但它们尚未被相互校准，特别是对于具有基质的生物样品。为了解决这一问题，我们系统地比较了气相色谱/燃烧/同位素比质谱（GC/C/IRMS）、制备液相色谱（LC）分离-元素分析仪/IRMS （LC × EA/IRMS）和LC分离- GC/C/IRMS （LC × GC/C/IRMS）三种方法的AA δ15N值。比较了鱼类肌肉中谷氨酸（δ15NGlu）和苯丙氨酸（δ15NPhe）的δ15N值，这是估计生物营养位置（TPs）的两个关键aa。虽然三种分析方法之间的鱼肌肉δ 15ngluu值存在显著差异，但它们的δ 15ngluu和δ 15npheu值在所有对方法之间相当一致（n= 8， GC/C/IRMS与LC × GC/C/IRMS的R2= 0.9968， LC × EA/IRMS与LC × GC/C/IRMS的R2= 0.9936， GC/C/IRMS与LC × EA/IRMS的R2= 0.9912），这导致三种方法之间的TP估计相似。因此，实验结果验证了CSIA - AA方法在跨学科研究领域的可比性。我们还强调了这三种分析方法的一些关键特征，这些特征可以作为未来CSIA - AA研究的指导方针。
Compound‐specific isotope analysis of nitrogen (δ15N) in amino acids (CSIA‐AA) has significantly contributed to environmental sciences such as anthropology, biogeochemistry, and ecology. Several methods exist for determining δ15N of amino acids (AAs). Although these methods have their own strength and weakness, they have not been intercalibrated yet, especially for biological samples with matrices. To address this issue, we systematically compared AA δ15N values among three methods using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), preparative liquid chromatography (LC) separation followed by elemental analyzer/IRMS (LC × EA/IRMS), and LC separation followed by GC/C/IRMS (LC × GC/C/IRMS). The δ15N values of glutamic acid (δ15NGlu) and phenylalanine (δ15NPhe) in fish muscle, two crucial AAs for estimating the trophic positions (TPs) of organisms, were compared among methods. Although a significant difference in fish muscle δ15NGluvalues was found among the three analytical methods, their δ15NGluand δ15NPhevalues were fairly consistent between all pairs of methods (n= 8,R2= 0.9968 for GC/C/IRMS vs. LC × GC/C/IRMS; 0.9936 for LC × EA/IRMS vs. LC × GC/C/IRMS; and 0.9912 for GC/C/IRMS vs. LC × EA/IRMS), which resulted in similar TP estimates among the methods. Thus, the results provide empirical validation that the CSIA‐AA is comparable among different methods in interdisciplinary research fields. We also highlighted some critical features of each of the three analytical methods that can be used as a guideline for future CSIA‐AA research.