Nanostructured polyaniline SPME fiber coating for chemical warfare agents analysis.

Nanostructured polyaniline (PANI) was electrochemically obtained as a fiber coating of solid-phase microextraction (SPME) and then used in the analysis of selected organoarsenic and organophosphorus compounds in soil samples. Also, comparative studies of the obtained PANI fibers with seven commercially available fibers for varying miscellaneous polarity, and various absorption and/or adsorption natures, were carried out. Quantitative analysis of environmental samples was performed using a gas chromatograph coupled with a tandem mass spectrometer. During the analysis of organophosphorus compounds, the PANI fiber showed at least 20% greater sorption efficiency than any commercially available fiber, whereas, in the case of organoarsenic compounds, the sorption efficiency of the PANI fiber increased with the expansion in the number of phenyl rings in the molecule. The PANI coating material was characterised by N2 adsorption-desorption, scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis. SEM imaging confirmed a nanostructured form of PANI. The repeatability for one fiber (n = 7), expressed as the relative standard deviation ranges from 3.2% to 4.4% depending on the kind of tested chemical compound. The reproducibility (calculated as relative standard deviation of the 9 prepared fibers) was not greater than 7.2% Under the optimized conditions, the proposed method was linear over approximately 4 orders for organophosphorus compounds (0.02-100 ng g-1) and 5 orders for organoarsenic compounds (0.12-5000 ng g-1) of magnitude for the tested compounds, with linear determination coefficients (R2) greater than 0.972, and the limit of detection for the home-made PANI fiber was relatively low (0.006-0.45 ng g-1). In comparison with all commercially available SPME fibers, the new PANI fiber was more selective for the tested aromatic and organophosphorus compounds and easily as well as inexpensively prepared. The resulting stationary phase allowed for quantitative analysis of selected organophosphorus and organoarsenic compounds from the group of warfare agents.

Acute aquatic toxicity of arsenic-based chemical warfare agents to Daphnia magna.

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems. The aim of this research was to support a need for real-data measurements for accurate risk assessments and categorization of threats originating from submerged CWAs. This has been achieved by providing a broad insight into arsenic-based CWAs acute toxicity in aquatic ecosystems. Standard tests were performed to provide a solid foundation for acute aquatic toxicity threshold estimations of CWA: Lewisite, Adamsite, Clark I, phenyldichloroarsine (PDCA), CWA-related compounds: TPA, arsenic trichloride and four arsenic-based CWA degradation products. Despite their low solubility, during the 48 h exposure, all CWA caused highly negative effects on Daphnia magna. PDCA was very toxic with 48 h D. magna LC50 at 0.36 µg × L-1 and Lewisite with EC50 at 3.2 µg × L-1. Concentrations at which no immobilization effects were observed were slightly above the analytical Limits of Detection (LOD) and Quantification (LOQ). More water-soluble CWA degradation products showed no effects at concentrations up to 100 mg × L-1.

The effects of chemical warfare agent Clark I on the life histories and stable isotopes composition of Daphnia magna.

Chemical warfare agents (CWA) dumped worldwide in all types of aquatic reservoirs pose a potential environmental hazard. Leakage of CWAs from eroding containers at dumping sites had been observed, and their presence in the tissues of aquatic animals was confirmed. However, the ecological effects of CWA have not yet been studied. In standardized laboratory bioassays, we tested if sublethal concentration of Clark I, an arsenic based CWA, can affect life histories (somatic growth rate, fecundity, size at maturity), population growth rate and stable isotope signatures of a keystone crustacean grazer Daphnia magna. We found that the life histories and fitness of daphnids reared in the presence of Clark I differed from those reared in Clark-free conditions. The effects were observed when Clark I concentrations were no less than 5 µg×L-1. With increasing concentrations of the tested CWA, all of the tested parameters decreased linearly. The finding indicates that even sublethal concentrations of Clark I can affect crustacean populations, which should be taken into account when assessing the environmental risks of this particular CWA. We found intraspecific diversity in susceptibility to Clark I, with some clones being significantly less vulnerable than others. We also found that in the presence of Clark I, the ratio of heavy and light isotopes of nitrogen in the bodies of daphnids was affected - daphnids exhibited δ15N enrichment with increasing concentrations of this CWA. The isotopic composition of carbon was not affected by the presence of Clark I. The nitrogen isotopic signature may be used as an indicator of stress in zooplankton exposed to the presence of toxic xenobiotics.

Analysis of samples of explosives excavated from the Baltic Sea floor.

After World War II, conventional and chemical ammunition containing mainly secondary and primary explosives was dumped in the sea. Explosives have medium toxicity to aquatic organisms, earthworms and indigenous soil microorganisms. Therefore, environmental monitoring is required, especially for dumped munitions. The main aspect of this work was to analyse the samples of lumps and sediments taken from the Baltic seabed. These samples were potentially explosives. The main goal of the study was to identify the type and composition of studied materials. In order to determine the chemical composition of samples of explosives, we used as follows: GC-MS/MS, LC-HRMS and NMR. Additionally, to determine the energetic properties we performed microcalorimetric-thermogravimetric analysis. Based on the obtained results, the composition of this explosive was TNT (41%), RDX (53%), aluminium powder (5%), and degradation products (below 1%). The resulting composition indicates that the analysed material can be classified in the "torpex" family, widely used during World War II. Regarding the results of the microcalorimetric analysis, we can conclude that excavated fragments of explosives are in very good condition and they still can detonate after being initiated. Therefore, there is a threat that they could be used for criminal or terrorist purposes.

Development of analytical methods used for the study of 2,4,6-trinitrotoluene degradation kinetics in simulated sediment samples from the Baltic Sea.

Large amounts of ammunition containing 2,4,6-trinitrotoluene (TNT) and other substances were dumped in the Baltic Sea after WWII. Considering progressive corrosion processes, studying the transformation of TNT occurring in the environment constitutes an important aspect of a possible associated risk. This study focused on the transformations of TNT in simulated conditions of the Baltic Sea bottom sediment. Methods of analysis of TNT and selected products of its transformations were developed for that purpose. The developed methods allowed for the determination of selected compounds below 1 ng/g. Systematic monitoring of TNT transformations in the environment of the bottom sediment was performed. This allowed for the determination of the kinetics of TNT degradation and identification of degradation reaction products. Based on the obtained results, the TNT decay half-time in conditions present in the Baltic Sea was estimated to be 16.7 years for the abiotic environment and 5.6 for the biotic environment.