A Toolbox for the Determination of Nitroaromatic Explosives in Marine Water, Sediment, and Biota Samples on Femtogram Levels by GC-MS/MS.

Tobias Bünning,Tom Bötticher,Ann Hollmann,Jennifer Strehse,Edmund Maser

doi:10.3390/toxics9030060

Abstract

To determine the amount of the explosives 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, and its metabolites in marine samples, a toolbox of methods was developed to enhance sample preparation and analysis of various types of marine samples, such as water, sediment, and different kinds of biota. To achieve this, established methods were adapted, improved, and combined. As a result, if explosive concentrations in sediment or mussel samples are greater than 10 ng per g, direct extraction allows for time-saving sample preparation; if concentrations are below 10 ng per g, techniques such as freeze-drying, ultrasonic, and solid-phase extraction can help to detect even picogram amounts. Two different GC-MS/MS methods were developed to enable the detection of these explosives in femtogram per microliter. With a splitless injector, limits of detection (LODs) between 77 and 333 fg/µL could be achieved in only 6.25 min. With the 5 µL programmable temperature vaporization—large volume method (PTV-LVI), LODs between 8 and 47 fg/µL could be achieved in less than 7 min. The detection limits achieved by these methods are among the lowest published to date. Their reliability has been tested and confirmed by measuring large and diverse sample sets.

Highlights

The release of nitro-aromatic explosives from corroding marine-dumped munitions is a worldwide problem with growing environmental concern [1]
For 2,4,6-trinitrotoluene (TNT), one of the main explosives used in bombs, grenades, mines, and torpedoes, accumulation has been proven in marine organisms, such as the blue mussel Mytilus edulis [3,4,5,6] and dab Limanda limanda [7,8]
With the methods presented in this study, reliable, fast, and sensitive determination of low explosive concentrations in marine samples, such as water, sediment, and marine biota are possible

Summary

Introduction

The release of nitro-aromatic explosives from corroding marine-dumped munitions is a worldwide problem with growing environmental concern [1]. In order to assess contamination of the North Sea and the Baltic Sea by the legacy of war as comprehensively as possible, with regard to present and future ecotoxicological consequences, the examination of large quantities of various abiotic and biotic samples for TNT, its metabolites, and other munitions components such as 1,3-dinitobenzene and 2,4-dinitrotoluene is required. Gas and liquid chromatography techniques have been routinely used in the detection of nitro-organic explosives for over fifty years [9,10]. Modern mass spectrometric techniques, such as triple, quadrupole, or Orbitrap mass spectrometry, allow limits of detection, depending on the components, in the range of femto- to atto-gram per injection [11]. Several publications have since been published dealing with the detection of various explosives and their metabolites in quite different matrices, such as the EPA methods 529 (explosives in drinking water by GC/MS) [12], 8330 (water, soil, and sediment by HPLC) [13], and

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Conclusion