Nucleophilic destruction of organophosphate toxins: A computational investigation

Computed reaction enthalpies, free energies, and activation barriers in vacuo are presented for the nucleophilic detoxification of the organophosphorus compounds (H)(HO)P(O)F, (H)(H₃CO)P(O)F and (H₃C)(CH(CH₃)₂O)P(O)F via the reaction R₁OH + (R₂)(R₃O)P(O)F → (R₂)(R₃O)P(O)(OR₁) + HF for a wide variety of R₁OH nucleophiles. Density functional theory at the B3LYP/6-311++G(d,p) computational level was employed for all the calculations. A multi-step Wright-type reaction mechanism [J. B. Wright, W.E. White, J. Mol. Struct. (THEOCHEM) 454 (1998) 259], which proceeds via a proton transfer from the nucleophile to the fluorine atom through the phosphinyl oxygen atom, was consistently found to have a lower activation barrier in the gas-phase than for the corresponding mechanism that operates via a proton transfer from the nucleophile directly to the fluorine atom. Of the nucleophilic agents investigated, peroxybenzoic acid and o-iodosobenzoic acid had the lowest classical activation barrier for the Wright-type mechanism.     

沙林酸印迹聚邻苯二胺纳米膜制备及结构表征

采用电化学聚合法合成了对有机磷毒剂沙林具有特异识别的聚邻苯二胺(PPD)分子印迹纳米膜(iPPD).利用石英晶体微天平(QCM)证实了印迹效应的存在，并用循环伏安法(CV)、AFM、XPS进行了系统的结构表征.结果表明，分子印迹膜的膜厚约20 nm，膜的表面呈“石林”状，疏松多孔，具有良好的吸附性能.分子印迹主要影响聚合物的三维排列，而聚合物的化学组成没有发生改变.该种分子印迹纳米膜在选择性检测军用毒剂沙林中具有良好的应用前景.     

Simultaneous analysis of sarin, pyridostigmine bromide and their metabolites in rat plasma and urine using HPLC

Summary A method was developed for the separation and quantification of the warfare nerve agent sarin (O-isopropylmethylphosphonoflouridate), its metabolite methylphosphonic acid, the anti nerve agent drug pyridostigmine bromide (PB;3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) and its metaboliteN-methyl-3-hydroxypyridinium bromide in rat plasma and urine. The method involved using solid phase extraction and high performance liquid chromatography (HPLC) with reversed phase C₁₈ column, and UV detection at 280 nm. The compounds were separated using gradient of 1% to 55% acetonitrile in 0.1% triflouroacetic acid water solution (pH 3.20) at flow rate of 0.9 ml/min in a period of 15 min. The retention times ranged from 4.4–12.1 min. The limits of detection were 50 ng mL⁻¹ for PB andN-methyl-3-hydroxypyridinium bromide, and 10 μg mL⁻¹ for sarin and methylphosphonic acid, while limits of quantitation were between 100 ng mL⁻¹–12 μg mL⁻¹. Average percentage recovery of five spiked samples from plasma were 84.6±8.4, 86.5±9.0, 76.4±8.5, 81.3±8.2, and from urine 78.5±7.9, 76.4±7.8, 74.4±8.4, 80.6±6.8 for sarin, methylphosphonic acid, pyridostigmine bromide andN-methyl-3-hydroxypyridinium bromide, respectively. This method was applied to analyze the above chemicals and metabolites following combined administration in rats.     

基于纳米β分子筛的石英晶体微天平沙林传感器研究

以纳米β(Cuβ)分子筛为敏感膜,结合石英晶体微天平(QCM)制备了对神经毒剂沙林(GB)敏感的传感器。结果表明,纳米β(Cuβ)分子筛对GB响应较纳米ZSM-5更灵敏,在热空气吹扫下可连续多次检测,其灵敏度为23.6Hz/(mg.m-3)(26.8Hz/(mg.m-3)),检出限(S/N=3)为0.96mg.m-3(0.90mg.m-3);线性范围1.50～18.24mg.m-3,线性相关系数为0.9910(0.9888)。该法在毒剂检测中具有一定的应用前景。     

Nerve Agents Assay Using Cholinesterase Based Biosensor

Electrochemical biosensor based on electric eel acetylcholinesterase (AChE) (EC 3.1.1.7) was performed for assay of nerve agents – tabun, sarin, soman, cyclosarin, and VX. The biosensor used AChE as biorecognition element. The presence of nerve agents was accompanied by a strong inhibition of AChE activity. Enzyme activity is easily measurable by electrochemical oxidation of thiocholine created from acetylthiocholine (ATChCl) by AChE‐catalyzed hydrolysis. The tested nerve agents were successfully assayed. The best limits of detection were achieved for sarin (5.88×10^?10 M) and VX (8.51×10^?10 M) after one‐minute assay. The biosensor was found long term stable at low as well as laboratory temperature.     

一种新型对苯乙炔基苯衍生物：荧光行为与传感应用

设计合成了一种以8-羟基喹啉(8-HQ)为捕获基团,胆固醇(Chol)为辅助结构的新型光化学稳定的对苯乙炔基苯(BPEB)衍生物(OPBMQ)。研究表明,该化合物荧光光谱由8-HQ的荧光发射和BPEB的荧光发射组成,且其荧光发射对沙林毒气模拟物(DCP)的存在极为敏感。计算检出限可达1 × 10⁻⁹ mol·L^-1以下。此外,其它相关神经毒剂模拟物、有机磷农药,甚至它们的混合物的存在均不显著干扰化合物对DCP的传感。更为重要的是,无论是以高纯水、自来水,还是海水作为介质,均对测定结果没有显著影响。需要指出的是,对沙林毒气模拟物的灵敏、高选择性测定也可以在滤纸片上以目视法进行。基于这些结果,发展了一种概念性沙林毒气模拟物检测仪器。     

Mass spectrometric determination of ergosterol in a prairie natural wetland

Packed capillary liquid chromatography–electrospray mass spectrometry (LC–ESI-MS) was used for the analysis of a snow sample that was accidentally contaminated with an organophosphorus chemical warfare agent during the destruction of a chemical munition. Sarin, its hydrolysis products and a number of related compounds were identified on the basis of acquired LC–ESI-MS data. Full mass spectra were acquired for 14 compounds, with all exhibiting MH⁺, [MH+ACN]⁺ ions and/or protonated dimers that could be used to confirm molecular mass. Sampling cone voltages from 20 to 70 V were utilized with the higher sampling voltages enhancing formation of structurally important product ions in the ESI interface. All data were acquired with a time-of-flight mass spectrometer with a resolution of 5000 (50% valley definition), a resolution that aided in the assignment of elemental composition of the observed ions. The application of LC–ESI-MS to snow analysis appears to be an attractive alternative to the GC–MS methods, since both chemical warfare agents and their hydrolysis products may be analysed directly, eliminating the need for additional sample handling and derivatization steps.     

In-line respeciation: an ion-exchange ion chromatographic method applied to the separation of degradation products of chemical warfare nerve agents in soil

The natural background of anions encountered when analyzing soil samples by ion chromatography (IC) present significant problems in the separation, detection and quantification of isopropyl methylphosphonic acid (IMPA) and methylphosphonic acid (MPA), the degradation products of sarin, a chemical warfare nerve agent. Using chemically-suppressed IC with conductivity detection, a commercially available ion-exchange column, and an isocratic binary eluent system, IMPA and MPA were determined in aqueous extracts of soil at sub-ppm (μg/g) concentrations without the need for gradient elution or organic solvent eluent modifiers. Common soil anions such as chloride, nitrate, sulfate and phosphate do not interfere with the analysis method due to the composition of the binary eluent allowing for greater mobilization of multivalent anions (e.g., MPA, carbonate, and sulfate) while monovalent anions (e.g., IMPA and nitrate) are relatively unaffected. Carbonate is selectively removed by in-line respeciation to bicarbonate.     

沙林和梭曼消毒产物的气相色谱-质谱法分析

建立了用消毒液ＤＳ２对含磷毒沙林和梭曼和消毒后的样品处理与制备的方法，使用气相色谱－质谱法对消毒后产物进行了分析与鉴定。对ＤＳ２消毒ＧＢ和ＧＤ反应的机理作了探讨。     

Dynamic solid phase microextraction for sampling of airborne sarin with gas chromatography-mass spectrometry for rapid field detection and quantification

A portable dynamic air sampler and solid phase microextraction were used to simultaneously detect, identify, and quantify airborne sarin with immediate analysis of samples using a field portable gas chromatography-mass spectrometry system. A mathematical model was used with knowledge of the mass of sarin trapped, linear air velocity past the exposed sampling fiber, and sample duration allowing calculation of concentration estimates. For organizations with suitable field portable instrumentation, these methods are potentially useful for rapid onsite detection and quantification of high concern analytes, either through direct environmental sampling or through sampling of air collected in bags.