DETERMINATION OF N-15-LABELED AMMONIUM AND TOTAL NITROGEN IN PLANT AND FUNGAL SYSTEMS USING MASS-SPECTROMETRY

被引：9

作者：

EK, H ^{[1
]}

FINLAY, RD ^{[1
]}

SODERSTROM, B ^{[1
]}

ODHAM, G ^{[1
]}

机构：

[1] UNIV LUND,DEPT MICROBIAL ECOL,S-22362 LUND,SWEDEN

来源：

JOURNAL OF MICROBIOLOGICAL METHODS | 1990年 / 11卷 / 3-4期

关键词：

!sup]15[!/sup]N; Ammonia; Ectomycorrhiza; Mass spectrometry; N assimilation;

D O I：

10.1016/0167-7012(90)90053-9

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

A selected ion-monitoring method to measure 15N-labelled ammonia in biological samples was improved to simplify sample handling, to obviate interference from ammonia due to the decomposition of glutamine and to allow the determination of total N. Ammonia is derivatized with pentafluorobenzoylchloride to yield pentafluorobenzamide which is analysed by gas chromatogrpahy/mass spectrometry after clean-up using disposable silicic acid columns. The sensitivity achieved when operating in the negative ion-chemical ionization mode was somewhat higher than when using electron-impact ionization. Use of methyl amine as an internal standard improved the accuracy and precision of the measurements. The method was applied to samples taken from an intact ectomycorrhizal system fed with 15N-labelled ammonium and used to determine patterns of N assimilation into ammonium, free amino acids and macromolecular compounds. © 1990.

引用

页码：169 / 176

页数：8

共 9 条

[1]

Biemann K., 1962, MASS SPECTROMETRY

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