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The growing use of explosives by terrorists and criminals creates a need for instrumentation which can rapidly analyze these energetic compounds, preferably on site. Direct analysis in real time (DART) is a promising technology for surface analysis with little or no sample preparation. Therefore, DART ionization is evaluated for use in detecting explosives on solid substrates and in liquid matrices. Fifteen explosives were chosen as a consequence of their common usage. Five surfaces were chosen to represent a wide range of physical properties such as composition, porosity, surface morphology, and thermal and electrical conductivity. Additionally these surfaces are commonly found in everyday surroundings. All 75 compound-surface combinations produced a clear, easily identifiable, mass spectra characteristic of the targeted analyte. Simultaneous detection of five explosives is demonstrated on these same surfaces. Lastly, rapid detection of trace contamination in common fluids is also explored.

The destruction of phosphorus based chemical warfare agents using aqueous buffer mixtures of aluminum sul- fate (alum) and sodium aluminate is pursued. The production of VX (O-ethyl-S-(2-(diisopropylamino)ethyl)-methylphos- phonothiolate) hydrolysis products ethyl methyl phosphonic acid (EMPA), an aluminum complex of EMPA, and S-(2- (diisopropylamino)ethyl)methylphosphonothiolate (EA-2192) is characterized in acidic and basic alum buffers. The study employs 31 P high resolution magic angle nuclear magnetic resonance spectroscopy (HRMAS NMR) for both quantitative and qualitative analysis. The acidic buffer results in a slower reaction rate and is less effective than the basic buffer.

The evaporation and degradation of VX (O-ethyl S-[2-N,N-(diisopropylamino)ethyl] methylphosphonothioate) on silica sand and borosilicate glass were measured using vapor analysis and 31P solid state magic angle spinning nuclear magnetic resonance (SSMAS NMR) spectroscopy. 31P SSMAS NMR studies of VX degradation on crushed glass, air-dried sand, and oven-dried sand at a variety of temperatures showed that the final product was nontoxic ethyl methylphosphonic acid (EMPA), produced via the toxic diethyl dimethylpyrophosphonate intermediate. The reaction exhibited a lag time that depended upon the quantity of water and EMPA that were present in the initial sample of VX and was autocatalytic; EMPA was both the catalyst and product for the degradation of VX. 31P SSMAS NMR studies of VX on moist sand at a variety of temperatures showed that the final product was nontoxic EMPA; observed intermediates were protonated VX, O-ethyl methylphosphonothioic acid, and toxic EA-2192 (S-[2-N,N-(diisopropylamino)ethyl methylp...

A new ion source has been developed for rapid, noncontact analysis of materials at ambient pressure and at ground potential. The new source, termed DART (for "Direct Analysis in Real Time"), is based on the reactions of electronic or vibronic excited-state species with reagent molecules and polar or nonpolar analytes. DART has been installed on a high-resolution time-of-flight mass spectrometer (TOFMS) that provides improved selectivity and accurate elemental composition assignment through exact mass measurements. Although DART has been applied to the analysis of gases, liquids, and solids, a unique application is the direct detection of chemicals on surfaces without requiring sample preparation, such as wiping or solvent extraction. DART has demonstrated success in sampling hundreds of chemicals, including chemical agents and their signatures, pharmaceutics, metabolites, peptides and oligosaccharides, synthetic organics, organometallics, drugs of abuse, explosives, and toxic industrial chemicals. These species were detected on various surfaces, such as concrete, asphalt, human skin, currency, airline boarding passes, business cards, fruits, vegetables, spices, beverages, body fluids, horticultural leaves, cocktail glasses, and clothing. DART employs no radioactive components and is more versatile than devices using radioisotope-based ionization. Because its response is instantaneous, DART provides real-time information, a critical requirement for screening or high throughput.

Self-association behavior and conformation variation of long chain branched (LCB) poly(2-ethyloxazoline) (PEOx) with a CH3-(CH2)17 (C18) modified surface are investigated using light scattering techniques in various solvents. It is found that this LCB-PEOx self-associates in less polar solvents to form metastable nanoaggregates instead of undergoing precipitation. The critical aggregation concentration (cac) of this LCB polymer was obtained from the sharp increase of both hydrodynamic radius (Rh) and scattering light intensity measured in dynamic light scattering. The cac strongly depends on solvent polarity, decreasing as the solvent becomes more hydrophobic. As the polarity of the solvent increases, C18 chains move from the outside surface to the interior. Inward movement of C18 chains can cause coupled LCB-polymer chains to move with them, resulting in shrinkage of the particle size. The self-association process in the LCB-PEOx involves intrachain (C18 chains) collapse and interchain association. By a ...

Analogs of the chemical warfare agent Sarin were synthesized using a microscale technique and analyzed with a gas chromatograph equipped with a light pipe Fourier Transform infrared spectrometer. Produced as byproducts of the chemical warfare agents, a variety of related organophosphonate byproducts were often also observed. Similarities and differences among the spectra within the classes are noted, including some distinguishing characteristics of the infrared spectra not previously cited in the literature.

Chemical neutralization is being explored as an alternative to incineration for a variety of demilitarization programs. Analytical methods are needed to detect and quantify residual agent in reaction masses produced from chemical neutralization to verify destruction of the agent and to clear a reaction mass for further processing. This paper describes the development and validation of gas chromatography–mass spectral methods for the trace determination of the chemical warfare agents isopropyl methylphosphonofluoridate (GB) and bis(2-chloroethyl)sulfide (HD) in solutions of the agents chemically neutralized with ethanolamine. ©2000 John Wiley & Sons, Inc. J Micro Sep 12: 87–92, 2000

This paper describes the method development and validation for detection of the chemical warfare agents HN-1 and HN-3 in air using C8 solid-phase extraction disks followed by liquid desorption and analysis by gas chromatography. The method is contrasted to the standard approach which uses solid sorbent tubes followed by thermal desorption and analysis by gas chromatography.

Decontamination waste from chemical weapons (CW) agents has been stored in ton containers on Johnston Atoll since 1971. The waste was recently sampled and analyzed to determine its chemical composition in preparation for disposal. Due to the range of products and analytical requirements, multiple chromatographic and spectroscopic methods were necessary, including gas chromatography/mass spectrometry (GC/MS), gas chromatography/atomic emission detection (GC/AED), liquid chromatography/mass spectrometry (LC/MS), capillary electrophoresis (CE), and nuclear magnetic resonance spectroscopy (NMR). The samples were screened for residual agents. No residual sarin (GB) or VX was found to detection limits of 20 ng/mL, but 3% of the samples contained residual sulfur mustard (HD) at

Inspection protocols for the Chemical Weapons Treaty, which went into effect on April 29, 1997 require on-site analytical procedures which include a comprehensive mass spectral database of hundreds of scheduled compounds. A number of these compounds were prepared on a nanogram scale via a micro-scale synthetic approach using GC-IRD/MSD analytical instrumentation to purify and identify the resulting products. The collected electron impact mass spectra will be made available for use in relevant databases.

Arsenic compounds, and especially organo‐arsenic derivatives, are highly toxic and many have been manufactured as chemical warfare agents. This study was designed to provide background information relevant to the potential application of aquathermolysis techniques for the detoxification of such potent military warfare agents. Six arsenic‐containing compounds with structural features which mimic known agents were studied in neutral superheated water: 4‐aminophenylarsine oxide, 4‐arsanilic acid, 4‐nitrophenylarsonic acid, 5, 10‐dihydro‐10‐ethylphenarsazine, tetraphenylarsonium chloride hydrate, and (3‐cyanopropyl)dimethyl(2‐phenethyl)arsonium bromide. Most of these compounds were moderately susceptible to hydrolysis for 1h at 300°C. o‐ and p‐Aminosubsituted arsenic compounds were more reactive than compounds with an electron‐withdrawing group substituent. Aromatic C—As bonds were more resistant to cleavage than aliphatic C—As bonds.

A method is described in which micellar electrokinetic chromatography (MEKC) is used to separate thiodiglycol, 2,2′-sulfinyldiethanol, 1,4-dithiane, 1,4-thioxane, O-isobutyl methylphosphonothioic acid and O-ethyl methylphosphonothioic acid in aqueous samples. Detection limits range from 1 to 10 μg/ml and the calibration curves are linear over two orders of magnitude. The compounds are separated in under 10 min. The method fulfills our requirements for a rapid, on-site screening technique for these compounds.

Two series of 2,4,6-triphenylverdazyls substituted at the C(3) position of the heterocyclic ring are obtained using new convenient synthetic methodology. Thus, crown ether assisted solid–liquid phase-transfer catalysis promotes the formation of 3-n-alkyl-substituted 2,4,6-triphenylverdazyls in the reactions of 1,3,5-triphenylformazan with n-alkyl bromides. Under PTC conditions, methylation of 3-(4-nitrophenyl)-1,5-diphenylformazan with methyl iodide exclusively gives the corresponding verdazyl radical. 3-Substituted 2,4,6-triphenylverdazyls containing various di(cyclo)alkylamino moieties at the C(3) position of the verdazyl ring are prepared by the reaction of 1,3,5-triphenylformazan with the corresponding 1-[N,N-di(cyclo)alkylaminomethyl]benzotriazoles under the efficient catalysis of barium hydroxide monohydrate. Sonication of this reaction allows the yields of the verdazyls to be substantially increased. A bis-verdazyl N,N-bonded in the C(3) positions was synthesized. All the radicals obtained were characterized by microanalysis, and by UV–visible and ESR spectroscopy.

Crown-formazan (1) with a pendant hydroxy group was obtained by a phase-transfer assisted azo-coupling reaction. Acylation of the hydroxy group of (1) with 2-chloroacetyl chloride followed by reaction with dimethylamine afforded 13-[2-(N,N-dimethylamino)acetoxy]-16,17-dihydro-7-phenyl-5H,15-dibenzo[b,i][1,11,4,5,7,8]dioxatetraazacyclotetradecyne (8), the first lariat crown-formazan containing a strong donor group as a supporting ligand at the end of the side arm.

β-(N,N-Dialkylamino)ethyl arylthiosulfonates 2, new simulants for the hydrolysis and oxidation chemistry of VX (1), are prepared in good yield by reaction of a potassium arylthiosulfonate with a 2-chloroethylamine. Alkaline hydrolysis of 2 results in cleavage of the S-S bond to give sulfinic acids and disulfides. Like VX, oxidation of 2 by N-sulfonyloxaziridine 12 occurs exclusively on nitrogen to give the corresponding amine oxide which subsequently undergoes a Cope elimination reaction affording the vinyl sulfide 14

Direct analysis in real time (DART) is an ion source that permits rapid mass spectrometric detection of gases, liquids, and solids in open air under ambient conditions. It is a unique technology in the field of chemical weapons detectors in that it does not require a vapor pressure, does not require sample preparation, and is nondestructive to the original sample. While the DART technique has had success as a first line instrument of detection, there have been lingering doubts over the technique's quantitative reliability and reproducibility. Here, we demonstrate its capability to produce linear calibration curves (R(2) = 0.99 or better) for the nerve agents GA, GB, and VX as well as the blister agent HD. Independently prepared check standards measured against these curves typically have recovery errors less than 3%. We show the DART instrument response to be linear over roughly 3 orders of magnitude. Furthermore, this study shows that averaging as few as three measurements for each data point is sufficient to produce high quality calibration curves, thus reducing data collection time and providing quicker results.

A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Greentrade mark, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO(4)(-2)) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t(1/2)or = 4 min), 1:10 for HD (t(1/2)2 min with molybdate), and 1:10 for GD (t(1/2)2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

The syntheses of five new 4-alkyl-2-iodosobenzoic acids (3) are described. The iodine atom was introduced by ortho-directed lithiation of 4-alkylbenzyl alcohols followed by treatment with I 2 . The catalytic effectiveness of each of the products in the hydrolysis of 4-nitrophenyl diphenyl phosphate in microemulsions was studied. The 4-methyl- and 4-ethyl-substituted products were each found to be significantly better catalysts than the standard nonalkylated 2-iodosobenzoic acid (3, R = H). These results would indicate that microemulsions of these materials may find use in detoxification procedures

We have measured the second order rate constants for the uncatalyzed and o-iodosobenzoate catalyzed hydrolysis of p-nitrophenyldiphenyl phosphate in microemulsions containing the surfactant cetyltrimethyl ammonium bromide, the cosurfactants 1-alkyl-2-pyrrolidinones, and the oils hexadecane, toluene, and 4-tert-butyltoluene. Pseudo-ternary phase maps have been prepared for systems containing 1-methyl-2-pyrrolidinone and 1-cyclohexyl-2-pyrrolidinone as cosurfactants. Microemulsions containing N-alkyl-2-pyrrolidinones as cosurfactants effectively penetrate polymers, solubilize phosphate esters, and provide media in which phosphate esters hydrolyze rapidly.

Poly(amidoamine) (PAMAM) dendrimer shell reagents possessing either nucleophilic (i.e., primary amines) or electrophilic (i.e., carboxymethyl esters) functional groups have been covalently assembled around appropriate electrophilic or nucleophilic dendrimer core reagents to produce partial shell filled/core-shell tecto(dendrimers). Partial shell-filled products with saturation levels ranging from 28% to 66% were obtained. These metastable, remarkably monodispersed assemblies possess functionally differentiated nano-cusps and clefts that exhibit “autoreactive” behavior. Pacification of these autoreactive products with appropriate alkanolamine reagents produced robust, nonreactive, “hydroxy-amine-differentiated” surfaces that exhibit very active self-assembly properties. Based on the monodispersity, dimensional scaling, and electrophoretic similarities of PAMAM dendrimers to globular proteins, these assemblies may be viewed as crude biomimetics of classical core shell-type protein aggregates. These dimensionally larger, but analogous PAMAM core-shell tecto(dendrimer) architectures extend and complete a similar pattern of autoreactivity and pacification that was observed earlier for traditional mono PAMAM dendrimer core-shell modules possessing unsaturated shell levels.

An amber yellow organic liquid was found in a munition shell at Dugway Proving Grounds, UT, USA, that was likely used as a simulant of chemical weapons. The primary analytical techniques to characterize the mixture were gas chromatography-infrared detection-mass spectral detection (GC-IR-MS); liquid chromatography-mass spectrometry (LC-MS); nuclear magnetic resonance (NMR) using the nuclei 1H, 13C and 31P; and gas chromatography-atomic emission detection (GC-AED). Six major phosphorus-containing components were identified and confirmed by at least three techniques, and several additional phosphorus-containing components of lower concentration have been identified by GC-IR-MS and LC-MS. Five major non-phosphorus components, including ethyl acetate, diethyl sulfide and dibutylamine, have been identified by multiple techniques. The major phosphorus compound (23.9+/-0.4 wt.%) was O,O,O-triethyl phosphorothioate (I) and the second most abundant (14.4+/-0.2 wt.%) was O,O,S-triethyl phosphorothioate (III). No VX, G-agent, or pesticide was observed in the sample, although III may be a cholinesterase inhibitor which produces delayed toxic response. III also produces a false hit for the pesticide cyanthoate when analyzed by GC-MS-EI. The mixture appears to have been formulated as a chemical warfare agent simulant, most likely as a challenge of agent detection techniques.

We explore a thermal separation technique for use with Direct Analysis in Real Time (DART). By applying gas temperature ramping, we are able to disburse a mixture of compounds in time. The three components were selected to create a challenging mixture that would not likely be discerned solely using exact mass capabilities. While the thermal separation technique is of low resolution, it preserves the inherent rapid, non-contact, ambient characteristics of the ion source.

Nerve agents VX and GB (sarin) are sequestered and removed by aluminium sulfate and sodium aluminate mixtures adjusted to pH 4 in solution. The products of hydrolysis are removed with the alum floc below NMR detection limits over time depending and the amount of aluminium molar excess relative to agent. Half-lives for GB decomposition are 3.1 h and 1.1 h, respectively, for a 120 and a 1200 molar excess. For VX, the half-lives are 8.5 d and 2.9 d for a 240 and a 5000 molar aluminium excess. In the case of GB, fluorine is sequestered as the hexafluoroaluminate ion. In the case of VX, no phosphorus containing hydrolysis products including the very toxic S-[2-(diisopropyl-amino)-ethyl]methylphosphonothiolate (EA-2192) are detected in the hydrolysate.

Schiff base boron and aluminium bromides have been used to cleave organophosphate nerve agents and pesticides and their simulants: salben(tBu)[BBr2]2 was very effective in cleaving the VX simulants EMPPT and DEPPT and nerve agent VX; salen(tBu)AlBr was effective in cleaving the nerve agents VX and Soman and the pesticideDiazinon.

The crystal structures of sodium 2-iodosyl-4-nitrobenzoate and sodium 2-iodyl-4-nitrobenzoate demonstrate a bicyclic structure for each, pKa, considerations indicate that the anions remain cyclized in solution. The crystal structure of 2-iodyl-5-methylbenzoic acid has also been obtained.

The 13C NMR, IR, and UV spectra of 3- and 4-iodobenzoic, 3- and 4-iodosylbenzoic, and 3- and 4-iodylbenzoic acids and their sodium salts have been measured and compared with those of the corresponding 2-isomers. Kinetic data for the catalytic microemulsion hydrolysis of 4-nitrophenyl diphenyl phosphonate in the presence of the iodosyl and iodyl compounds have been obtained. Catalytic efficiency of the 3- and 4-substituted isomers are measured to be three to six orders of magnitude less effective than the corresponding 2-substituted isomers. Possible structural configurations are suggested and discussed.

Utilisation pour l'hydrolyse d'esters carboxyliques et d'ester phosphates en presence de chlorure de cetyltrimethylammonium

The principles involved in macroheterocycle chemistry are discussed. Classes and types of macroheterocycles, synthetic approaches (including the template effect), complexation and complexes are mentioned. The utilization of crown ethers in synthetic organic chemistry is also surveyed. 1. Introduction 1.1. History 1.2. Nomenclature and Characteristics 1.3. Classes of Crowns and Related Molecules 2. Synthetic Access 2.1. Templated Syntheses 2.2. Non-Williamson Syntheses 3. Complexation 3.1. The Complexation Phenomenon 3.2. Types of Complexes 4. Synthetic Utility 4.1. Solubilization and Phase Transfer 4.2. Cation Effects 4.3. Crowns as Reagents and Catalysts 4.4. Complexation Specificity 5. Toxicity 6. Conclusions

The 13C NMR spectra for selected 2-iodosobenzoic acids, their sodium salts and the sodium salts of the corresponding iodoxybenzoic acids were measured and carbon assignments made using 2D and NOE experiments and relaxation times. Iodoso and iodoxy groups deshielded the ipso-carbon in these compounds by approximately 25 and 55 ppm, respectively, relative to the corresponding iodo compounds. The 13C NMR spectra of the 2-iodosobenzoate anions were almost identical with those of the corresponding free acids, both possessing cyclic structures. The iodoxybenzoic acids are either insoluble in, or oxidize, suitable NMR solvents (i.e. DMSO-d6, DMF-d7). The cyclic structure postulated for iodoxybenzoate anions is supported by their 13C chemical shifts.

The 13 C spin-lattice relaxation times (T 1 's) of cryptands [2.1.1], [2.2.1] and [2.2.2] as well as those of the corresponding cryptate complexes with Li + , Na + , and K + in CDCl 3 and CH 3 OH:D 2 O (90:10) were measured and the results are interpreted in terms of molecular compression and desolvation effects.

Two polymer-bound iodosobenzoate derivatives have been prepared and found to be phosphorolytically active against both p -nitrophenyldiphenyl phosphate and the nerve agent, Soman.

Available data on the structures, electronic substituent effects and 13 C NMR spectra of aromatic polyvalent iodine compounds, particularly iodoso and iodoxy derivatives, are summarized and discussed. A series of aromatic tri- and penta-valent iodine compounds were synthesized, their 13 C NMR spectra were measured and the substituent chemical shifts (SCS) for several polyvalent iodine functional groups were calculated. As the oxidation state of iodine increases (I → II → V), the strong shielding of the ipso-carbon atom by iodine in aryl iodides due to the 'heavy-atom effect' (30 ppm) decreases substantially, and this decrease is apparently general for stable hypervalent iodine compounds. Possible explanations are discussed and correlations between chemical shifts, structures and/or electronic effects are proposed.

Influence d'acides iodosyl-2 et iodyl-2 benzoiques sur la vitesse d'hydrolyse du (diphenyl nitro-4 phenyl) phosphate, de l'(isopropyl O-[nitro-4 phenyl] phenyl) phosphinate, et de l'hexanoate de p-nitrophenyle

Seven surfactants have been synthesized, each containing a 4-(dialkylamino)pyridine moiety carrying an 8-10-carbon chain with an attached polar or charged group. Two of the compounds fall into the neutral charge category, two are cationic, two are zwitterionic, and one is anionic. Rates of hydrolysis of 4-nitrophenyl hexanoate and 1,2,2-trimethylpropyl methylphosphonofluoridate by each surfactant were measured, both with and without added cetyltrimethylammonium chloride (CTAC). The most active derivative, sodium 10- [butyl(4-pyridinyl)amino]decyl sulfate (12), catalyzed the hydrolysis of 4-nitrophenyl hexanoate with k2 = 38.0 M-' s-l at pH 8.5, which compares favorably to the catalysis by o-iodosobenzoate derivatives investigated by Moss and co-workers. The present catalysts, in contrast to the iodosobenzoates, show poor rate enhancements in the hydrolysis of fluorophosphonates.

Hydrolyse des esters trimethyl-1,2,2 propyle et isopropyle de l'acide methyl phosphonofluoridique (soman et sarin respectivement), du N,N-dimethyl phosphoramidocyanidate d'ethyle (tabum) et du (diethyl nitro-4 phenyl) phosphate dans des solutions aqueuses micellaires de chlorure de (palmityl trimethyl) ammonium, en presence d'acide iodosyl-«2» benzoique

Etude des effets de divers coagents de surface: butanol-1, N,N-dibutylformamide, Adogen 464, et des substituants du catalyseur sur la vitesse d'hydrolyse du phosphate du titre dans des microemulsions huile eau stabilisees par le chlorure ou le bromure de (palmityl trimethyl) ammonium