国际权威刊物"Rapid Communications in Mass Spectrometry"发表最新文章,指出采用激光光谱同位素仪(无论是LGR还是Piccaro公司)分析植物与土壤样品会产生极大误差,建议还是采用传统的同位素比率质谱仪才能获得可靠的结果。该文摘要和文献出处如下:
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
Rapid Commun. Mass Spectrom. 2010; 24: 1948–1954
Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/rcm.4597
Discrepancies between isotope ratio infrared spectroscopy and isotope ratio mass spectrometry for the stable isotope analysis of plant and soil waters
Adam G. West1,2*, Gregory R. Goldsmith1, Paul D. Brooks3 and Todd E. Dawson1,3
1Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
2Botany Department, University of Cape Town, Rondebosch, 7701, South Africa
3Center for Stable Isotope Biogeochemistry, University of California, Berkeley, Berkeley, CA 94720, USA
Received 7 April 2010; Revised 24 April 2010; Accepted 24 April 2010
The use of isotope ratio infrared spectroscopy (IRIS) for the stable hydrogen and oxygen isotope
analysis of water is increasing. While IRIS has many advantages over traditional isotope ratio mass
spectrometry (IRMS), it may also be prone to errors that do not impact upon IRMS analyses. Of
particular concern is the potential for contaminants in the water sample to interfere with the
spectroscopy, thus leading to erroneous stable isotope data. Water extracted from plant and soil
samples may often contain organic contaminants. The extent to which contaminants may interfere
with IRIS and thus impact upon data quality is presently unknown. We tested the performance of
IRIS relative to IRMS for water extracted from 11 plant species and one organic soil horizon. IRIS
deviated considerably from IRMS for over half of the samples tested, with deviations as large as 46%
(d2H) and 15.4% (d18O) being measured. This effect was reduced somewhat by using activated
charcoal to remove organics from the water; however, deviations as large as 35% (d2H) and 11.8%
(d18O) were still measured for these cleaned samples. Interestingly, the use of activated charcoal to
clean water samples had less effect than previously thought for IRMS analyses. Our data show that
extreme caution is required when using IRIS to analyse water samples that may contain organic
contaminants. We suggest that the development of new cleaning techniques for removing organic
contaminants together with instrument-based software to flag potentially problematic samples are
necessary to ensure accurate plant and soil water analyses using IRIS. Copyright# 2010 John Wiley
& Sons, Ltd.