Soil amino acid composition quantified by acid hydrolysis and anion chromatography-pulsed amperometry.
Soil amino acid composition quantified by acid hydrolysis and anion chromatography-pulsed amperometry.
复制标题
DOI：
10.1021/jf034422e
复制
发表时间：
2003-09
影响因子：
6.1
通讯作者：
D. Martens;Kevin L Loeffelmann
中科院分区：
文献类型：
--
作者：
D. Martens;Kevin L Loeffelmann
土壤有机氮占土壤全氮含量的95-98%，氨基酸（AA）和氨基糖（AS）是土壤中主要的有机氮化合物，而传统的6 M HCl回流或密封消解24 h及各种检测系统，AA-N仅占土壤全氮含量的30-40%。本研究比较了传统的盐酸提取方法与甲磺酸（MSA）水解和nonderivatized AA和AS定量离子色谱脉冲安培检测器测定植物凋落物和土壤中的AA组合物。MSA（4 M）的AA-N回收率相当于或优于6 M HCl的植物AA digestion（16小时，121摄氏度，104千帕）。使用4 M MSA（0.5-1.5 h，136 ℃，112 kPa）使土壤（n = 22）中有机氮以AA、AS和NH（4）（+）形式的总回收率增加了46%，与之相比，6 M HCl（12 h，110 ℃，回流）的MSA回收率为总氮含量的85.6%（n = 22土壤）。较短的MSA土壤消化时间（0.5-1.5小时）表明，大部分土壤有机氮不存在于植物凋落物分析（16小时消化）中发现的蛋白质形式。MSA离子色谱分析土壤AA/AS组合物是一个强大的非衍生化方法，需要很少的样品制备，可以区分土壤AA组合物在一个生长季节，由于植被和耕作管理的小变化。
Soil organic N accounts for 95-98% of the total soil N content with amino acids (AAs) and amino sugars (ASs) identified as the major soil organic N compounds, but traditional 6 M HCl with reflux or sealed digestions for 24 h and various detection systems have accounted for only 30-40% of soil total N content as AA-N. This study compared traditional HCl extraction methodology with methanesulfonic acid (MSA) hydrolysis and nonderivatized AA and AS quantification by ion chromatography with pulsed amperometric detection for determination of the AA composition of plant litter and soils. MSA (4 M) gave AA-N recovery comparable to or better than 6 M HCl for plant AA digestions (16 h, 121 degrees C, 104 kPa). Use of 4 M MSA (0.5-1.5 h, 136 degrees C, 112 kPa) increased the total recovery of organic N as AAs, ASs, and NH(4)(+) by 46% from soils (n = 22) compared with 6 M HCl (12 h, 110 degrees C, reflux) with a MSA recovery rate of 85.6% of the total N content (n = 22 soils). The shorter MSA soil digestions (0.5-1.5 h) suggested that the majority of soil organic N was not present as protein forms found in plant litter analysis (16 h of digestion). MSA ion chromatographic analysis for soil AA/AS composition is a robust nonderivatization method requiring little sample preparation that can distinguish between small changes in soil AA composition during one growing season due to vegetation and tillage managements.