Transformation of phenylarsenic chemical warfare agents and their effect on bacterial communities in Baltic Sea sediment

During the World Wars large quantities of phenylarsenic chemical warfare agents (CWAs) were dumped in the Baltic Sea. Many transformation products of these chemicals have been identified, but the pathways that produce the found chemicals has not been investigated. Here we studied the biotic and abiotic transformation of phenylarsenic CWAs under oxic and anoxic conditions and investigated how the sediment bacterial communities are affected by CWA exposure. By chemical analysis we were able to identify seventeen CWA-related phenylarsenicals, four of which (methylphenylarsinic acid (MPAA), phenylthioarsinic acid (PTAA), phenyldithioarsinic acid (PDTAA) and diphenyldithioarsinic acid (DPDTAA)) have not been reported for marine sediments before. For the first time PTAA was verified from environmental samples. We also observed equilibrium reactions between the found transformation products, which may explain the occurrence of the chemicals. 16S rRNA-analysis showed that bacterial communities in sediments are affected by exposure to phenylarsenic CWAs. We observed increases in the amounts of arsenic-resistant and sulphur-metabolising bacteria. Different transformation products were found in biotic and abiotic samples, which suggests that bacteria participate in the transformation of phenylarsenic CWAs. We propose that methylated phenylarsenicals are produced in microbial metabolism and that chemical reactions with microbially produced sulphur species form sulphur-containing transformation products.

Computational analysis of an electrostatic separator design for removal of volatile organic compounds from indoor air

Concentrations of volatile organic compounds (VOCs) in air can be reduced in electrostatic separators where VOCs are ionized using ion-molecule reactions, extracted using electric fields, and eliminated in a waste flow. Embodiments for such separator technology have been explored in only a few studies, despite the possible advantage of purification without adsorbent filters. In one design, based on ionization of VOCs in positive polarity with hydrated protons as reactant ions, efficiencies for removal were measured as 30-40% . The results were fitted to a one-dimensional convective diffusion model requiring an unexpectedly high production rate of reactant ions to match both the model and data. A realistic rate of reactant ion production was used in finite element method simulations (COMSOL) and demonstrated that low removal efficiency could be attributed to non-uniform patterns of sample flow and to incomplete mixing of VOCs with reactant ions. In analysis of complex systems, such as this model, even limited computational modeling can outperform a pure analytical approach and bring insights into limiting factors or system bottlenecks.Implications: In this work, we applied modern computational methods to understand the performance of an air purifier based on electrostatics and ionized volatile organic compounds (VOCs). These were described in the publication early 2000s. The model presented was one-dimensional and did not account for the effects of flow. In our multiphysics finite element models, the efficiency and operation of the filter is better explained by the patterns of flow and flow influences on ion distributions in electric fields. In general, this work helps using and applying computational modelling to understand and improve the performance bottlenecks in air purification system designs.

Chlorinated organic compounds in concrete as specific markers for chlorine gas exposure

The formation of chlorinated organic compounds in concrete debris exposed to reactive chlorine was studied to search for markers specific to chlorine gas exposure. Concrete materials of different origins were exposed to a range of species of reactive chlorine including bleach, humid and dry chlorine gas at different concentrations. Chlorinated organic compounds in concrete extracts were analysed by targeted gas and liquid chromatography-tandem mass spectrometry (GC-MS/MS and LC-MS/MS) and by non-targeted screening using the corresponding high-resolution techniques (GC-HRMS and LC-HRMS). Overall, different levels and species of chlorinated organic compounds namely chlorophenols, chlorobenzenes, chloromethoxyphenols, chloromethylbenzenes and chloral hydrate were identified in these chlorinated concrete extracts; two examples of diagnostic markers for neat chlorine exposure were trichloromethylbenzene and tetrachlorophenol. The old concrete samples from the 1930s and 1950s had the most chlorinated organic compounds after exposure to neat chlorine gas. Lignin or lignin degradation products were identified as probable candidates for phenolic precursor molecules in the concrete samples. Multivariate data analysis (OPLS-DA) shows distinct patterns for bleach and chlorine exposure. The chlorinated chemicals and specific markers for chlorine gas discovered in our research assist other laboratories in forensic investigations of chlorine gas attacks.

Quantitative Distributions of Product Ions and Reaction Times with a Binary Mixture of VOCs in Ambient Pressure Chemical Ionization

A model to quantitatively predict ion abundances from atmospheric pressure chemical ionization (APCI) between hydrated protons and a volatile organic compound (VOC) was extended to binary mixtures of VOCs. The model includes differences in vapor concentrations, rate coefficients, and reaction times and is enhanced with cross reactions between neutral vapors and protonated monomers. In this model, two specific VOCs were considered, a ketone, 6-methyl-5-hepten-2-one (M, and an amine, 2,6-di-tert-butyl-pyridine (N), with measured "conditional rate coefficients" (in cm³·s^-1) of k_M = 1.11 × 10^-9 and k_N = 9.17 × 10^-10, respectively. The cross reaction of MH⁺(H₂O)_x to NH⁺(H₂O)_y was measured as k_cr = 1.31 × 10^-12 at 60 °C. Cross reactions showed an impact on ion abundances at t > 30 ms for equal vapor concentrations of 100 ppb for M and N. In contrast, this impact was negligible for vapor concentrations of 1 ppb and did not exceed 5% change in product ion abundance up to 1000 ms reaction times. The model was validated with laboratory measurements to within ∼10% using an ion mobility spectrometer and effective reaction time obtained from computational fitting of experimental findings. This was necessitated by complex flow patterns in the ion source volume and was determined as ∼10.5 ms. The model has interpretative and predictive value for quantitative analysis of responses with ambient pressure ion sources for mass spectrometry and ion mobility spectrometry.

Glutathione conjugation of nitrogen mustards: In vitro study

RATIONALE

This paper describes an in vitro study designed to identify metabolic biomarkers resulting from the conjugation of nitrogen mustards (NMs) with glutathione (GSH). The method developed is essential in providing evidence in the event of NM exposure in biomedical samples.

METHODS

The mass spectral characterization of the proposed NMs-GSH conjugates was performed with liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). The final reaction mixtures were analysed in positive electrospray ionisation (ESI) at different incubation times.

RESULTS

This study identified three types of conjugates in addition to ethanolamines, the hydrolysis products of NMs. Monoglutathionyl, diglutathionyl and phosphorylated conjugates were produced for each of the NMs, bis(2-chloroethyl)ethylamine (HN1), bis(2-chloroethyl)methylamine (HN2) and tris(2-chloroethyl)amine (HN3). The monoglutathionyl conjugates consisted of HN1-GSH, HN2-GSH and HN3-GSH. The spontaneous and primary conjugates of diglutathionyl were HN1-GSH2, HN2-GSH2 and HN3-GSH2. These included phosphorylated conjugates, namely HN1-GSH-PO₄ , HN2-GSH-PO₄ and HN3-GSH-PO₄ , as might have formed due to hydrolysis in phosphate buffer.

CONCLUSIONS

The mass spectral data of all conjugates formed in the presence of all NMs and GSH are reported in this study. These GSH metabolites can be used to confirm NMs toxicity in biological samples such as urine.

Metabolism and cytotoxicity of diphenylarsinic acid, a degradation product of sea-dumped chemical warfare agents, in a rainbow trout liver cell line RTL-W1

Recent studies have found primary degradation products of phenylarsenic chemical warfare agents (CWAs) accumulating in fish tissues, while the potential effects of these dumped phenylarsenic CWAs, such as Clark I and II, in the Baltic Sea biota are poorly understood. In this study, the metabolism and cytotoxicity of diphenylarsinic acid (DPA), a primary degradation product of phenylarsenic CWA, was studied by incubating rainbow trout cell line RTL-W1 cells in media with 100 mg/L DPA. Previously undescribed metabolites were identified by ultra-high performance liquid chromatography-high resolution mass spectrometry (UPHLCHRMS). Moreover, the cytotoxicity of diphenylarsine glutathione conjugate (DPA-SG), the major metabolite of DPA, was studied. Cytotoxicity of the compounds was evaluated using the Neutral Red retention test (NRR), showing an IC₅₀ value of 278 mg/L for DPA and 1.30 mg/L for DPA-SG, indicating that the glutathione (GSH) conjugate of DPA is more than two orders of magnitude toxic than DPA itself, suggesting that toxic properties of DPA are increased after conjugation with intracellular GSH leading enhanced toxicity after uptake. Results gained in this study give more detailed information for elucidating biological effects of dumped chemical munitions in marine environment. Moreover, the results help in assessing the environmental and health risks posed by marine munition continued presence and deterioration in the sea bottom.

Osmolal and anion gaps after acute self-poisoning with agricultural formulations of the organophosphorus insecticides profenofos and diazinon: A pilot study

Self-poisoning with organophosphorus (OP) insecticides is an important means of global self-harm. The insecticides are formulated with solvents that may also contribute to toxicity. We set up a study to detect changes in osmolal and anion gaps following ingestion of OP insecticides. We recruited consecutive patients admitted to a Teaching Hospital, Sri Lanka, with a history of OP self-poisoning. The osmolal and anion gaps were calculated on admission and at 4, 24 and 72 h post-ingestion together with ethanol concentration. Forty-nine patients were recruited (28 profenofos, 10 diazinon, one coumaphos, one chlorpyrifos, one phenthoate and eight unknown OP). Only modest increases in osmolal and anion gaps were noted. Small rises in osmolal gap above the upper limit of normal were noted in 16/49 (32.7%) of all cases, 9/28 (32.1%) profenofos cases and 4/10 (40.0%) diazinon cases. The anion gap was raised in 24/49 (49.0%) of all cases, 15/28 (53.6%) profenofos cases and 5/10 (50.0%) diazinon cases. We observed a trend for a fall in osmolal gap during the first 24 h, followed by an increase up to 72 h. There was no correlation between the anion gap and serum lactate concentration, indicating that a lactic acidosis was not responsible for the anion gap. Formate, which could have explained the increased gap, was not detected in any of the samples; ketoacids (beta-hydroxybutyrate and acetoacetate) were not measured. This pilot study found that profenofos and diazinon poisoning caused only modest increases in the osmolal and anion gaps in a minority of cases.

Parametric Sensitivity in a Generalized Model for Atmospheric Pressure Chemical Ionization Reactions

Gas phase reactions between hydrated protons H⁺(H₂O)_n and a substance M, as seen in atmospheric pressure chemical ionization (APCI) with mass spectrometry (MS) and ion mobility spectrometry (IMS), were modeled computationally using initial amounts of [M] and [H⁺(H₂O)_n], rate constants k₁ to form protonated monomer (MH⁺(H₂O)_x) and k₂ to form proton bound dimer (M₂H⁺(H₂O)_z), and diffusion constants. At 1 × 10¹⁰ cm^-3 (0.4 ppb) for [H⁺(H₂O)_n] and vapor concentrations for M from 10 ppb to 10 ppm, a maximum signal was reached at 4.5 μs to 4.6 ms for MH⁺(H₂O)_x and 7.8 μs to 46 ms for M₂H⁺(H₂O)_z. Maximum yield for protonated monomer for a reaction time of 1 ms was ∼40% for k₁ from 10^-11 to 10^-8 cm³·s^-1, for k₂/k₁ = 0.8, and specific values of [M]. This model demonstrates that ion distributions could be shifted from [M₂H⁺(H₂O)_z] to [MH⁺(H₂O)_x] using excessive levels of [H⁺(H₂O)_n], even for [M] > 10 ppb, as commonly found in APCI MS and IMS measurements. Ion losses by collisions on surfaces were insignificant with losses of <0.5% for protonated monomer and <0.1% for proton bound dimer of dimethyl methylphosphonate (DMMP) at 5 ms. In this model, ion production in an APCI environment is treated over ranges of parameters important in mass spectrometric measurements. The models establish a foundation for detailed computations on response with mixtures of neutral substances.

Optimized method for analysis of ethanolamines, hydrolysis products of nitrogen mustards, from urine samples using LC-MS/MS

Highly polar ethanolamines (EAs), excreted in urine, are hydrolysis products of nitrogen mustards (NMs), which are prohibited by the Chemical Weapons Convention (CWC). The methods established for biological matrices are essential for verification analysis of the CWC related chemicals. This paper describes a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method developed for qualitative and quantitative analysis of EAs, N-ethyldiethanolamine (EDEA), N-methyldiethanolamine (MDEA) and triethanolamine (TEAOH) from urine samples. After optimization of sample preparation and chromatographic conditions, the method was fully validated. Silica solid-phase extraction (SPE) cartridges and a porous graphite carbon (PGC) column were selected for validation studies. The method is linear from 5 to 500, 0.5 to 250, and 0.5 to 500 ng/mL for TEAOH, EDEA, and MDEA, respectively. It is also precise and accurate. A minimum sample amount of 0.5 mL urine was used. The limit of quantification using this approach was 0.4, 5.5, and 6.3 ng/mL for MDEA, EDEA and TEAOH, respectively. The combination of the PGC column and high pH eluents in analysis retained and separated the studied EAs. Retention times were 2.11, 2.56 and 2.98 min for MDEA, EDEA and TEAOH, respectively. The method is applicable for verification analysis of the CWC.

Quantum mechanical reference spectrum simulation for precursors and degradation products of chemicals relevant to the Chemical Weapons Convention

A selection of acidic, alkaline and neutral degradation products relevant to the Chemical Weapons Convention was studied in wide range of pH conditions to determine their spin systems as well as spectral parameters. The pH dependence of chemical shifts and J couplings was parameterized using Henderson-Hasselbalch-based functions using dichloromethane as additional shift reference in TSP-d₄ referenced spectra. The resulting parameters allowed calculation of precise chemical shifts and J coupling constants in arbitrary pH conditions. The validity of the obtained spin system definitions and parameters as a source of quantum mechanically simulated reference data in chemical verification analysis is demonstrated.

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.

Detection of chemical warfare agent related phenylarsenic compounds and multibiomarker responses in cod (Gadus morhua) from munition dumpsites

Recently, sea-dumped chemical weapons (CWs) containing toxic chemical warfare agents (CWAs) have raised international attention. It is well known that CWAs are leaking from corroded munitions causing a risk to the surrounding marine environment, while the impact on marine biota is still unknown. In this study, cod (Gadus morhua) was used as a model species to study the possible bioaccumulation of phenylarsenic CWAs and their negative effects at multiple levels of biological organization on fish living in the vicinity of a major CWs dumpsite in the Bornholm Basin in the Baltic Sea. In total, 14% of the cod muscle samples collected close to the main dumpsite contained trace levels of phenylarsenic CWAs. However, most of the biomarkers measured did not show clear differences between this area compared with a lesser contaminated reference area. On the other hand, significant changes in some biomarkers were observed in individuals containing trace levels of CWA-related chemicals. The results gained in this study have significant importance for environmental risk assessment and for evaluating the risk of CWA contamination for human seafood consumers.

Fast, Miniaturized, Real-Time Unit for Sampling, Modulation, and Separation in Detection of Hazardous Chemicals

A sampling, modulation, and separation (SMS) unit was tested for detection of hazardous chemicals. The SMS unit, designed and developed for on-site sampling and analysis, consists of a dynamic inlet system coupled with a fast, miniaturized gas chromatograph (GC). Feasibility of the SMS unit was evaluated together with a hazardous chemical vapor generator. The performance of the SMS unit was tested with automated thermal desorption after SMS to collect samples for GC-mass spectrometry (GC-MS) measurements. Detection of sarin nerve agent was verified. Additionally, the vapor generator was connected to the SMS unit, which was hyphenated with a photoionization detector (PID), thus creating a fast GC-PID system. This system gave a positive response for degradation products of sulfur mustard, thereby indicating suitability of the SMS-PID unit for field drone applications.

Biological effects of dumped chemical weapons in the Baltic Sea: A multi-biomarker study using caged mussels at the Bornholm main dumping site

After World War II, thousands of tons of highly toxic chemical warfare agents (CWA) were deposited in the Baltic Sea, the main dumping site locating in the Bornholm Basin. In the present study, Baltic mussels (Mytilus trossulus) were transplanted in the area in cages at two hotspot sites and a reference site at the depths of 35 and 65 m for 2.5 months to study bioaccumulation and biological effects of CWA possibly leaking from the corroding warfare materials. No traces of degradation products of the measured phenylarsenic CWA could be detected in the tissues of mussels. Nevertheless, several biochemical and histochemical biomarkers, geno- and cytotoxicity indicators, and bioenergetic parameters showed significant responses. The Integrated Biomarker Index calculated from the single biomarkers also showed a higher total response at the two hotspot areas compared to the reference site. Although no direct evidence could be obtained confirming the responses being caused specifically by exposure to CWA, the field exposure experiment showed unambiguously that organisms in this sea area are confronting environmental stress affecting negatively their health and this is likely related to chemical contamination, which is possibly connected to the sea-dumped CWA.

Exposure status of sea-dumped chemical warfare agents in the Baltic Sea

About 50 000 tons of chemical weapons (CW) were dumped to the Baltic Sea after the Second World War. Munitions are located in the deep areas of the Baltic Sea, and there they act as a point source of contamination to the ecosystem. Corroded munitions release chemical warfare agents (CWAs) to nearby water and sediments. In this study we investigated known dumpsites (Bornholm, Gotland and Gdansk Deep) and dispersed chemical munitions, to evaluate the extent of contamination of nearby sediments, as well as to assess the degradation process of released CWA. It was found that CWA-related phenylarsenic chemicals (Clark I, Clark II and Adamsite) and sulfur mustard are released to the sediments and undergo environmental degradation to chemicals, of which some remain toxic. The extent of pollution of released CWAs and their corresponding degradation products reaches more than 250 m from the CW objects, and seem to follow a power curve decrease of concentration from the source. Bornholm Deep is characterised with the highest concentration of CWAs in sediments, but occasional concentration peaks are also observed in the Gdansk Deep and close to dispersed munitions. Detailed investigation of spreading pattern show that the range of pollution depends on bottom currents and topography.

Studying the metabolism of toxic chemical warfare agent-related phenylarsenic chemicals in vitro in cod liver

Large quantities of chemical warfare agents (CWAs), such as phenylarsenic chemicals, were disposed by sea-dumping after World War II. Nowadays, the release of these toxic chemicals from munitions poses a potential threat to living organisms. This study investigates the fate of these chemicals in fish by exposing selected CWA-related phenylarsenic chemicals and their oxidation products to cod (Gadus morhua) liver S9 fraction in vitro. Clark I (DA), Adamsite (DM) and their corresponding oxidation products as well as triphenylarsine oxide (TPA[ox]) and phenylarsonic acid (PDCA[ox]) were used as chemicals in in vitro experiments. Glutathione (GSH) conjugates of DA, DM and PDCA-related chemicals were found to be the most dominant metabolites, and methylated metabolites were detected as well, suggesting that these compounds are metabolised in the presence of cod liver enzymes. TPA[ox] was the only compound tested that did not form a GSH conjugate or methylated metabolite, indicating a different biotransformation pathway for this compound. Furthermore, hydroxylated metabolites were detected for each tested chemical. Due to their reactive nature, GSH conjugates may be difficult to detect in fish samples from CWA dumpsites. In contrast, both methylated and hydroxylated metabolites of phenylarsenic chemicals are promising target chemicals for the detection of CWA-related contamination in fish.

Identification of Degradation Products of Sea-Dumped Chemical Warfare Agent-Related Phenylarsenic Chemicals in Marine Sediment

Previously unknown phenylarsenic chemicals that originated from chemical warfare agents (CWAs) have been detected and identified in sediment samples collected from the vicinity of chemical munition dumpsites. Nontargeted screening by ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) was used for detection of 14 unknown CWA-related phenylarsenic chemicals. Methylated forms of Clark I/II, Adamsite, and phenyldichloroarsine were detected in all analyzed sediment samples, and their identification was based on synthesized chemicals. In addition, other previously unknown CWA-related phenylarsenic chemicals were detected, and their structures were elucidated using MS/HRMS technique. On the basis of relative isotope ratios of protonated molecules and measures of exact masses of formed fragment ions, it could be concluded that some of these unknown chemicals contained a sulfur atom attached to an arsenic atom. In addition to that, some of the samples contained chemicals that had formed via addition of an OH group to the aromatic ring. However, it is not possible to say how these chemicals are formed, but the most plausible cause is activities of marine microbes in the sediment. To our knowledge, these chemicals have not been detected from sediment samples previously. Sensitive analytical methods are needed for these novel chemicals to assess the total CWA burden in marine sediments, and this information is essential for the risk assessment.

Molecularly Imprinted Polymer Materials as Selective Recognition Sorbents for Explosives: A Review

Explosives are of significant interest to homeland security departments and forensic investigations. Fast, sensitive and selective detection of these chemicals is of great concern for security purposes as well as for triage and decontamination in contaminated areas. To this end, selective sorbents with fast binding kinetics and high binding capacity, either in combination with a sensor transducer or a sampling/sample-preparation method, are required. Molecularly imprinted polymers (MIPs) show promise as cost-effective and rugged artificial selective sorbents, which have a wide variety of applications. This manuscript reviews the innovative strategies developed in 57 manuscripts (published from 2006 to 2019) to use MIP materials for explosives. To the best of our knowledge, there are currently no commercially available MIP-modified sensors or sample preparation methods for explosives in the market. We believe that this review provides information to give insight into the future prospects and potential commercialization of such materials. We warn the readers of the hazards of working with explosives.

Toxic effects of chemical warfare agent mixtures on the mussel Mytilus trossulus in the Baltic Sea: A laboratory exposure study

Baltic blue mussels (Mytilus trossulus) were implemented to assess potential toxicity, health impairments and bioaccumulation of dumped chemical warfare agents on marine benthic organisms. Mussels were collected from a pristine cultivation side and exposed under laboratory conditions to different mixtures of chemical warfare agents (CWAs) related phenyl arsenic compounds, Clark I and Adamsite as well as chloroacetophenone. Using a multi-biomarker approach, mussels were assessed thereafter for effects at different organisational levels ranging from geno-to cytotoxic effects, differences in enzyme kinetics and immunological responses. In an integrated approach, chemical analysis of water and tissue of the test organisms was performed in parallel. The results show clearly that exposed mussels bioaccumulate the oxidized forms of chemical warfare agents Clark I, Adamsite (DAox and DMox) and, to a certain extent, also chloroacetophenone into their tissues. Adverse effects in the test organisms at subcellular and functional level, including cytotoxic, immunotoxic and oxidative stress effects were visible. These acute effects occurred even at the lowest test concentration.

pH-Dependent Piecewise Linear Correlation of 1H,31P Chemical Shifts: Application in NMR Identification of Nerve Agent Metabolites in Urine Samples

The NMR-observable nuclei of the acidic and basic compounds experience pH dependence in chemical shift. This phenomenon can be exploited in NMR titrations to determine p K_a values of compounds, or in pH measurement of solutions using dedicated pH reference compounds. On the other hand, this sensitivity can also cause problems in, for example, metabolomics, where slight changes in pH result in significant difficulties for peak alignment between spectra of set of samples for comparative analysis. In worst case, the pH sensitivity of chemical shifts can prevent unambiguous identification of compounds. Here, we propose an alternative approach for NMR identification of pH-sensitive analytes. The ¹H and X (¹³C, ¹⁵N, ³¹P, ...) chemical shifts in close proximity to the acidic or basic functional group should, when presented as ordered pairs, express piecewise linear correlation with distinct slope, intercept, and range. We have studied the pH dependence of ¹H and ³¹P chemical shifts of the CH₃-P moiety in urinary metabolites of nerve agents sarin, soman and VX using 2D ¹H-³¹P fast-HMQC spectroscopy. The ¹H and ³¹P chemical shifts of these chemicals appear in very narrow range, and due to subtle changes in sample pH the identification on either ¹H or ³¹P chemical shift alone is uncertain. However, if the observed ¹H and ³¹P chemical shifts of the CH₃-P moiety of individual compounds are presented as ordered pairs, they fall into distinct linear spaces, thus, facilitating identification with high confidence.

Application of comprehensive NMR-based analysis strategy in annotation, isolation and structure elucidation of low molecular weight metabolites of Ricinus communis seeds

INTRODUCTION

Powder-like extract of Ricinus communis seeds contain a toxic protein, ricin, which has a history of military, criminal and terroristic use. As the detection of ricin in this "terrorist powder" is difficult and time-consuming, related low mass metabolites have been suggested to be useful for screening as biomarkers of ricin.

OBJECTIVE

To apply a comprehensive NMR-based analysis strategy for annotation, isolation and structure elucidation of low molecular weight plant metabolites of Ricinus communis seeds.

METHODOLOGY

The seed extract was prepared with a well-known acetone extraction approach. The common metabolites were annotated from seed extract dissolved in acidic solution using (1)H NMR spectroscopy with spectrum library comparison and standard addition, whereas unconfirmed metabolites were identified using multi-step off-line HPLC-DAD-NMR approach.

RESULTS

In addition to the common plant metabolites, two previously unreported compounds, 1,3-digalactoinositol and ricinyl-alanine, were identified with support of MS analyses.

CONCLUSION

The applied comprehensive NMR-based analysis strategy provided identification of the prominent low molecular weight metabolites with high confidence.

Characterization of Ricin and R. communis Agglutinin Reference Materials

Ricinus communis intoxications have been known for centuries and were attributed to the toxic protein ricin. Due to its toxicity, availability, ease of preparation, and the lack of medical countermeasures, ricin attracted interest as a potential biological warfare agent. While different technologies for ricin analysis have been established, hardly any universally agreed-upon "gold standards" are available. Expert laboratories currently use differently purified in-house materials, making any comparison of accuracy and sensitivity of different methods nearly impossible. Technically challenging is the discrimination of ricin from R. communis agglutinin (RCA120), a less toxic but highly homologous protein also contained in R. communis. Here, we established both highly pure ricin and RCA120 reference materials which were extensively characterized by gel electrophoresis, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS), and matrix-assisted laser desorption ionization-time of flight approaches as well as immunological and functional techniques. Purity reached >97% for ricin and >99% for RCA120. Different isoforms of ricin and RCA120 were identified unambiguously and distinguished by LC-ESI MS/MS. In terms of function, a real-time cytotoxicity assay showed that ricin is approximately 300-fold more toxic than RCA120. The highly pure ricin and RCA120 reference materials were used to conduct an international proficiency test.

Applying human and pig hepatic in vitro experiments for sulfur mustard study: screening and identification of metabolites by liquid chromatography/tandem mass spectrometry

RATIONALE

Sulfur mustard is a chemical warfare agent (CWA) with high toxicity and complex metabolism. This study aimed at identification of new metabolic biomarkers for sulfur mustard using in in vitro exposures and various mass spectrometric techniques.

METHODS

Human and pig liver subcellular fractions were used as biocatalysts. Metabolites were screened by liquid chromatography and tandem mass spectrometry (LC/MS/MS) using positive electrospray ionization (ESI). For structural identification, product ion scans (MS/MS, MS(3) ) and accurate mass measurements using liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) were acquired.

RESULTS

Sulfur mustard is metabolized in vitro by S-oxidation and glutathione (GSH) conjugations. One S-oxidized metabolite, bis(2-chloroethyl) sulfoxide (m/z 175), was formed in both species only when liver microsomes were present in incubations, and it was the main metabolite if GSH was not added into the reaction mixture. However, conjugation with GSH was found to be a spontaneous reaction in physiological pH and buffered solution. Three GSH conjugates of sulfur mustard were detected and identified, among which two were novel; 2-((2-(S-glutathionyl)ethyl)thio)ethanol (m/z 412) and 2-((2-(S-glutathionyl)ethyl)thio)ethyl phosphate (m/z 492).

CONCLUSIONS

To our knowledge, this was the first time that S-oxidized metabolites and GSH conjugates of sulfur mustard have been detected and identified from human samples in vitro by LC/MS/MS. The usefulness of the GSH conjugates to serve as biomarkers for sulfur mustard exposure in human samples requires further studies.

Methodology for national risk analysis and prioritization of toxic industrial chemicals

The identification of chemicals that pose the greatest threat to human health from incidental releases is a cornerstone in public health preparedness for chemical threats. The present study developed and applied a methodology for the risk analysis and prioritization of industrial chemicals to identify the most significant chemicals that pose a threat to public health in Finland. The prioritization criteria included acute and chronic health hazards, physicochemical and environmental hazards, national production and use quantities, the physicochemical properties of the substances, and the history of substance-related incidents. The presented methodology enabled a systematic review and prioritization of industrial chemicals for the purpose of national public health preparedness for chemical incidents.

Verification and quantification of saxitoxin from algal samples using fast and validated hydrophilic interaction liquid chromatography-tandem mass spectrometry method

Hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was validated with algal samples for verification and quantification of saxitoxin (STX), a potent neurotoxin which is listed in the Chemical Weapons Convention (CWC) in Schedule 1A. Isocratic elution, conventional bore HILIC column and high flow rate together with accurate post-column splitter provided detection of STX in 6.5 min with total analysis time of 9 min per sample. STX analogue, gonyautoxin 1 (GTX 1) was used as an internal standard. Sample preparation of freeze-dried algae included liquid extraction and centrifugal filtering with mean recovery of 99.9% at concentration level of 10 ng/ml (n=3). Retention times for STX and GTX 1 were 6.47±0.03 min and 4.44±0.01 min (n=45), respectively. Four diagnostic product ions were used for reliable verification of saxitoxin. Method was found to be precise and linear (R(2)=0.9714 and R(2)=0.9768) in concentration ranges of 5-50 ng/ml and 25-200 ng/ml, respectively. For saxitoxin, calculated LOD was 3 ng/ml and LLOQ 11 ng/ml. Validation was conducted using spiked algal matrix since this method is not only needed for verification analysis for the CWC but also for safety analysis of other environmental samples for presence of STX. Identification criteria for verification of STX with HILIC-MS/MS method are discussed.

Capsaicinoids, chloropicrin and sulfur mustard: possibilities for exposure biomarkers

Incapacitating and irritating agents produce temporary disability persisting for hours to days after the exposure. One can be exposed to these agents occupationally in industrial or other working environments. Also general public can be exposed in special circumstances, like industrial accidents or riots. Incapacitating and irritating agents discussed in this review are chloropicrin and capsaicinoids. In addition, we include sulfur mustard, which is an old chemical warfare agent and known to cause severe long-lasting injuries or even death. Chloropicrin that was used as a warfare agent in the World War I is currently used mainly as a pesticide. Capsaicinoids, components of hot pepper plants, are used by police and other law enforcement personnel as riot control agents. Toxicity of these chemicals is associated particularly with the respiratory tract, eyes, and skin. Their acute effects are relatively well known but the knowledge of putative long-term effects is almost non-existent. Also, mechanisms of effects at cellular level are not fully understood. There is a need for further research to get better idea of health risks, particularly of long-term and low-level exposures to these chemicals. For this, exposure biomarkers are essential. Validated exposure biomarkers for capsaicinoids, chloropicrin, and sulfur mustard do not exist so far. Metabolites and macromolecular adducts have been suggested biomarkers for sulfur mustard and these can already be measured qualitatively, but quantitative biomarkers await further development and validation. The purpose of this review is, based on the existing mechanistic and toxicokinetic information, to shed light on the possibilities for developing biomarkers for exposure biomonitoring of these compounds. It is also of interest to find ideas for early effect biomarkers considering the need for studies on subchronic and chronic toxicity.

Evaluation of a chemical munition dumpsite in the Baltic Sea based on geophysical and chemical investigations

This paper discusses the results of geophysical and chemical investigations carried out in a chemical munition dumpsite in the southern Baltic Sea, east of the island of Bornholm. After WW2 over 32,000 tons of chemical war material was dumped here including shells and bombs as well as small drums and containers. The geophysical investigations combined very-high-resolution seismics and gradiometric measurements. The results indicate the presence of a large number of objects buried just below the seafloor. The size of the objects and their distribution, with a marked increase in density towards the center of the dumpsite, suggests that we are dealing with dumped war material. Sediment and near-bottom water samples, taken within the dumpsite and in the surrounding area, were analysed for the presence of various chemical warfare agents (CWA) including Adamsite, Clark, sulphur mustard, tabun, chlorobenzene and arsine oil. The results indicate a widespread contamination that reaches far beyond the dumpsite boundary. CWA degradation products were found in most of the sediment samples. The contamination was mostly related to arsenic containing compounds; only one sample indicated the presence of sulfur mustard. Although the correlation between detected objects and CWA concentrations is not always straightforward, the overall results suggest that a lot of the dumped war material is leaking and that over the years the contamination has reached the seafloor sediments.

Environmental hazards of sea-dumped chemical weapons

Does the post-WWII burial at sea of chemical weapons still pose a human and environmental risk?

Screening and Identification of Organophosphorus Compounds Related to the Chemical Weapons Convention with 1D and 2D NMR Spectroscopy

Two-dimensional 1H-31P Fast-HMQC was tested for determination of the presence in low concentrations of organophosphorus compounds related to the Chemical Weapons Convention. This method, based on inverse detection, demonstrated high sensitivity and selectivity. Background signals, such as solvent peaks, are suppressed with good efficiency, and organophosphorus compounds present at a concentration level 1-10 microg/mL can be detected within a few hours. In addition, phosphorus-selective one-dimensional 1H-31P HSQC-TOCSY was applied to produce a complete proton spectrum of selected organophosphorus compound from a sample containing intense background resonances. Application of the methods presented in this paper resulted in considerably improved performance of NMR spectroscopy as a complementary technique for screening as well as identification of chemical warfare agents in environmental samples.

A 100-kDa urinary protein is associated with insulin resistance in offspring of type 2 diabetic patients

AIMS/HYPOTHESIS

One-third of normoalbuminuric type 1 diabetic patients show immunoreactive nephrin in urine. Offspring of type 2 diabetic patients are insulin-resistant and susceptible to the development of diabetes. We investigated whether the offspring of type 2 diabetic patients show nephrin in urine and whether possible nephrinuria is associated with insulin resistance.

METHODS

Urinary proteins from timed overnight urine collections from 128 offspring of type 2 diabetic patients and 9 control subjects were analysed by western blotting using an antibody against nephrin. Glucose metabolism was assessed by OGTT and IVGTT and the euglycaemic-hyperinsulinaemic clamp technique.

RESULTS

Of the offspring, 12.5% were strongly and 14.1% weakly positive for a 100-kDa urinary protein. All controls were negative. During the first 10 min of an IVGTT, the offspring strongly positive for the urinary protein had a higher insulin response than the offspring without the protein (3,700 vs 2,306 pmol l(-1)min(-1), p=0.007). Insulin sensitivity (the rate of whole-body glucose uptake divided by the steady-state insulin level x 100) was lower among the offspring strongly positive for the urinary protein than among the offspring negative for the protein (11.3 vs 15.8 micromol kg(-1)min(-1)pmol(-1)l(-1), p=0.008).

CONCLUSIONS/INTERPRETATION

A 100-kDa urinary protein detectable with a nephrin antibody is associated with insulin resistance in offspring of type 2 diabetic patients.

Site dependent bioavailability and metabolism of levosimendan in dogs

Site specific bioavailability and metabolism of levosimendan was studied in ten dogs by placing intestinal access port catheters in different parts of the gastrointestinal tract. 14C-labelled levosimendan (0.1 mg/kg) was administered intravenously, by gastric tube and directly through catheters that were placed in the duodenum, jejunum and ileum. Plasma samples were collected and radioactivity in the different organs and tissues was measured. The results of the present study showed that bioavailability of levosimendan was high varying from 71 to 86% after extravascular administration. Metabolite OR-1855 concentrations in the plasma were about 3-4 times higher after administration to the ileum compared to the other administration routes. It can be concluded that the bioavailability of levosimendan is not affected by site specific administration. The bacteria or enzymes responsible for the metabolism of levosimendan are located in the lower parts of the gastrointestinal tract.

Fine root biomass of Scots pine stands differing in age and soil fertility in southern Finland

The biomass of small and large fine roots (</= 2 mm and 2-5 mm in diameter, respectively) in mineral soils of southern Finland was compared with estimated foliage biomass in the same stands. Study material was collected from stands differing in site fertility and age. The humus layer was deeper at the more fertile sites than at the less fertile sites. Fine root density was greater in humus than in mineral soil, and the fine root density in mineral and humus layers was greater at the less fertile sites than at the more fertile sites. Although the amount of fine root biomass was not correlated with any commonly recorded stand characteristic, small fine root biomass was proportional to foliage biomass for both site types. The coefficient of proportionality was larger for the less fertile sites than for the more fertile sites, supporting the theory of functional balance. A similar relationship could not be established for the large fine roots. A trend of increasing fine root:needle mass ratio with stand age was observed for stands on the less fertile sites.