Bernstein Anat, Ronen Zeev, Adar Eilon, Nativ Ronit, Lowag Harald, Stichler Willibald, Meckenstock Rainer U
Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel.
Environ Sci Technol. 2008 Nov 1;42(21):7772-7. doi: 10.1021/es8005942.
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a common contaminant at explosives production sites. Here, we report on the use of compound-specific isotope analysis of RDX to obtain delta(15)N and delta(18)O enrichment factors during biodegradation in batch cultures. A new preparation method has been developed based on RDX purification using thin-layer chromatography. RDX is then subjected to an elemental analyzer coupled with an isotope-ratio mass spectrometer (EA-IRMS). The precision of the method shows standard deviations of 0.13% per hundred and 1.18% per hundred for delta(15)N and delta(18)O, respectively, whereas the accuracy of the method has been checked routinely, adhering to external standards. The method was applied to RDX samples subjected to biodegradation under aerobic or anaerobic conditions. Enrichment factors under aerobic conditions were -2.1% per hundred and -1.7% per hundred for delta(15)N and delta(18)O, respectively, and under anaerobic conditions, -5.0% per hundred and -5.3% per hundred for delta(15)N and delta(18)O, respectively. The results of this study provide a tool for monitoring natural attenuation of RDX in a contaminated environment.
六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）是炸药生产场地的常见污染物。在此，我们报告了利用RDX的化合物特异性同位素分析来获取分批培养生物降解过程中的δ¹⁵N和δ¹⁸O富集因子。基于使用薄层色谱法纯化RDX，开发了一种新的制备方法。然后将RDX置于与同位素比率质谱仪联用的元素分析仪（EA-IRMS）中进行分析。该方法的精密度显示，δ¹⁵N和δ¹⁸O的标准偏差分别为千分之0.13和千分之1.18，而该方法的准确性已按照外部标准进行常规检查。该方法应用于在需氧或厌氧条件下进行生物降解的RDX样品。需氧条件下，δ¹⁵N和δ¹⁸O的富集因子分别为千分之-2.1和千分之-1.7，厌氧条件下，δ¹⁵N和δ¹⁸O的富集因子分别为千分之-5.0和千分之-5.3。本研究结果为监测受污染环境中RDX的自然衰减提供了一种工具。
