Institut National de la Recherche Scientifique, Centre Eau, Terre et Environnement, 490 de la Couronne, Québec, Qc G1K 9A9, Canada.
J Chromatogr A. 2012 Aug 24;1252:130-5. doi: 10.1016/j.chroma.2012.06.082. Epub 2012 Jul 2.
A large number of laboratory studies have reported nitrite (NO(2)(-)) and nitrate (NO(3)(-)) to be among the most common degradation products of the high explosives nitroglycerin (NG) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Additionally, several field studies have reported the presence of RDX or NG along with NO(3)(-) in groundwater near production plants. Most studies, however, did not specify whether their NO(2)(-) and NO(3)(-) analyses were performed on samples which also contained RDX or NG. Inconsistent NO(2)(-)/NO(3)(-) results obtained in our laboratory suggested that the presence of RDX or NG in water samples caused an overestimation of NO(2)(-) and NO(3)(-) concentrations when using two of the most common analytical methods, namely ionic chromatography and automated colorimetry. This could have important implications for mass balance calculations and for environmental decisions. This paper focused on quantifying the overestimation of NO(2)(-)/NO(3)(-) due to the presence of RDX and NG, and finding a method for extracting RDX and NG from water samples without affecting NO(2)(-)/NO(3)(-). Results showed that the overestimation can be predicted using regression coefficients; however the margin of error at the 95% confidence level was between 5 and 15%. Alternatively, a cartridge was found which retains both RDX and NG without affecting NO(2)(-)/NO(3)(-). The cartridge can be used for concentrating the RDX or NG in dilute environmental samples, while removing RDX/NG from solution to allow the interference-free analysis of NO(2)(-)/NO(3)(-). Additionally, if recovery of RDX/NG from the cartridges is not desired, the cartridges could be used for the extraction of more than one sample, thus reducing the costs.
大量的实验室研究报告指出，亚硝酸盐（NO2(-)）和硝酸盐（NO3(-)）是高爆炸药硝化甘油（NG）和六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）最常见的降解产物之一。此外，一些现场研究报告称，在生产厂附近的地下水中存在 RDX 或 NG 以及 NO3(-)。然而，大多数研究并未具体说明他们的 NO2(-) 和 NO3(-)分析是否是在样品中也含有 RDX 或 NG 的情况下进行的。我们实验室获得的不一致的 NO2(-)/NO3(-)结果表明，当使用两种最常用的分析方法，即离子色谱法和自动比色法时，水样中 RDX 或 NG 的存在会导致对 NO2(-) 和 NO3(-)浓度的高估。这对质量平衡计算和环境决策可能具有重要意义。本文重点定量研究了由于 RDX 和 NG 的存在而导致的对 NO2(-)/NO3(-)的高估，并找到了一种从水样中提取 RDX 和 NG 而不影响 NO2(-)/NO3(-)的方法。结果表明，可以使用回归系数来预测高估；但是在 95%置信水平下的误差幅度在 5 到 15%之间。或者，发现了一种可以同时保留 RDX 和 NG 而不影响 NO2(-)/NO3(-)的试剂盒。该试剂盒可用于浓缩环境样品中的 RDX 或 NG，同时将 RDX/NG 从溶液中去除，以实现对 NO2(-)/NO3(-)的无干扰分析。此外，如果不希望从试剂盒中回收 RDX/NG，则可以使用试剂盒对多个样品进行提取，从而降低成本。
