空气中二氧化碳δ(13)C的自动气体样本采集及同位素比率质谱分析的优化

Optimization of automated gas sample collection and isotope ratio mass spectrometric analysis of delta(13)C of CO(2) in air.

作者信息

Zeeman Matthias J, Werner Roland A, Eugster Werner, Siegwolf Rolf T W, Wehrle Günther, Mohn Joachim, Buchmann Nina

机构信息

Institute of Plant Sciences, ETH Zurich, Universitaetstrasse 2, CH-8092 Zurich, Switzerland.

出版信息

Rapid Commun Mass Spectrom. 2008 Dec;22(23):3883-92. doi: 10.1002/rcm.3772.

DOI:10.1002/rcm.3772

PMID:18988208

Abstract

The application of (13)C/(12)C in ecosystem-scale tracer models for CO(2) in air requires accurate measurements of the mixing ratios and stable isotope ratios of CO(2). To increase measurement reliability and data intercomparability, as well as to shorten analysis times, we have improved an existing field sampling setup with portable air sampling units and developed a laboratory setup for the analysis of the delta(13)C of CO(2) in air by isotope ratio mass spectrometry (IRMS). The changes consist of (a) optimization of sample and standard gas flow paths, (b) additional software configuration, and (c) automation of liquid nitrogen refilling for the cryogenic trap. We achieved a precision better than 0.1 per thousand and an accuracy of 0.11 +/- 0.04 per thousand for the measurement of delta(13)C of CO(2) in air and unattended operation of measurement sequences up to 12 h.

摘要

将(^{13}C/^{12}C)应用于生态系统尺度的空气中(CO_2)示踪模型，需要精确测量(CO_2)的混合比和稳定同位素比。为提高测量可靠性和数据可比性，并缩短分析时间，我们用便携式空气采样装置改进了现有的野外采样设置，并开发了一种实验室设置，用于通过同位素比率质谱法（IRMS）分析空气中(CO_2)的(\delta^{13}C)。改进包括：（a）优化样品和标准气体流路；（b）额外的软件配置；（c）低温捕集阱液氮补充的自动化。我们实现了空气中(CO_2)的(\delta^{13}C)测量精度优于千分之一，准确度为千分之(0.11\pm0.04)，并能在长达12小时的测量序列中实现无人值守操作。