Synthesis and analysis of phosphorylated nonapeptide adducts by LC/Q-TOF MS

A new method for the synthesis of organophosphorylated adducts of the nonapeptide FGESAGAAS is presented. The adducts were obtained by using sarin (GB) or soman (GD) as the organophosphorylating reagents and cesium carbonate as the acid scavenger. Greater than 50% of the peptide was modified on serine 4. MS/MS spectra acquired on an Agilent 6520 quadrupole time of flight mass spectrometer demonstrated that serine 4, but not serine 9 in the nonapeptide, was modified. The adducts included the characteristic isopropyl group of sarin and the pinacolyl group of soman, indicating that aging had not occurred. It was concluded that the new synthetic method yielded sarin and soman-modified peptides that could be used as references when analyzing human exposure to these nerve agents.     

Synthesis of a potential reactivator of acetylcholinesterase—1-(4-hydroxyiminomethylpyridinium)-3-(carbamoylpyridinium)propane dibromide

Two methods for the synthesis of a new unsymmetric bispyridinium oxime-1-(4-hydroxyiminomethylpyridinium)-3-(carbamoylpyridinium)propane dibromide are described. In vitro efficacy of this new oxime to reactivate sarin-inhibited acetylcholinesterase has been evaluated.     

Rotational spectrum of cyclohexyl sarin

The rotational spectrum of cyclohexyl sarin (also known as GF) has been measured in a jet-cooled expansion using Fourier transform microwave spectroscopy. Two spectra have been observed, each having splittings associated with the internal rotation of the CH₃P group. The observed V₃ barriers are similar in magnitude to those reported for other organophosphonate nerve agents. The two conformational structures of GF have been identified from comparisons of the observed rotational constants and dipole moment magnitudes with ab initio predictions at the MP2/6311G (d,p) level. These two structures are distinguished by the placement of the fluorophosphonate group at the equatorial and axial positions of the cyclohexane ring. The data also suggest that both conformers prefer a positioning of the FP group with the PO oxygen in an eclipsed orientation relative to the C₁ hydrogen on the ring.     

丝网印刷胆酯酶电极测定神经性毒剂沙林,梭曼

将丝网印刷电化学传感器制作技术与戊二醛蒸汽熏蒸的酶固定化方法相结合制作了一次性使用胆碱酯酶电极（ＡＣhＥ）,并用于神经性毒剂沙林和梭曼的测定。以氯化硫代乙酰胆碱 （ＡＴＣh）为底物,该酶电极在pＨ７．２、温度３７℃时有最大响应。酶催化反应的动力学常数为：Ｋm＝３．５ｍｍｏｌ／Ｌ,Ｉｍａｘ＝２．５ｕＡ。沙林、梭曼抑制酶电极响 应,百分抑制率为毒剂浓度的对数呈线性关系。当抑制时间为２ｍｉｎ时,测定沙林、梭曼     

Analysis of Organophosphorus-Based Nerve Agent Degradation Products by Gas Chromatography-Mass Spectrometry (GC-MS): Current Derivatization Reactions in the Analytical Chemist’s Toolbox

The field of gas chromatography-mass spectrometry (GC-MS) in the analysis of chemical warfare agents (CWAs), specifically those involving the organophosphorus-based nerve agents (OPNAs), is a continually evolving and dynamic area of research. The ever-present interest in this field within analytical chemistry is driven by the constant threat posed by these lethal CWAs, highlighted by their use during the Tokyo subway attack in 1995, their deliberate use on civilians in Syria in 2013, and their use in the poisoning of Sergei and Yulia Skripal in Great Britain in 2018 and Alexei Navalny in 2020. These events coupled with their potential for mass destruction only serve to stress the importance of developing methods for their rapid and unambiguous detection. Although the direct detection of OPNAs is possible by GC-MS, in most instances, the analytical chemist must rely on the detection of the products arising from their degradation. To this end, derivatization reactions mainly in the form of silylations and alkylations employing a vast array of reagents have played a pivotal role in the efficient detection of these products that can be used retrospectively to identify the original OPNA.     

UiO-66-NH2 and Zeolite-Templated Carbon Composites for the Degradation and Adsorption of Nerve Agents

Composites of metal-organic frameworks and carbon materials have been suggested to be effective materials for the decomposition of chemical warfare agents. In this study, we synthesized UiO-66-NH₂/zeolite-templated carbon (ZTC) composites for the adsorption and decomposition of the nerve agents sarin and soman. UiO-66-NH₂/ZTC composites with good dispersion were prepared via a solvothermal method. Characterization studies showed that the composites had higher specific surface areas than pristine UiO-66-NH₂, with broad pore size distributions centered at 1–2 nm. Owing to their porous nature, the UiO-66-NH₂/ZTC composites could adsorb more water at 80% relative humidity. Among the UiO-66-NH₂/ZTC composites, U_0.8Z_0.2 showed the best degradation performance. Characterization and gas adsorption studies revealed that beta-ZTC in U_0.8Z_0.2 provided additional adsorption and degradation sites for nerve agents. Among the investigated materials, including the pristine materials, U_0.8Z_0.2 also exhibited the best protection performance against the nerve agents. These results demonstrate that U_0.8Z_0.2 has the optimal composition for exploiting the degradation performance of pristine UiO-66-NH₂ and the adsorption performance of pristine beta-ZTC.     

Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation

The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman, tabun and nitrogen mustards were higher. Some CWA simulants and organic solvents gave the ion peaks eluting at the similar positions of the CWAs, resulting in false positive alarms.     

氟离子重活化-气相色谱质谱法检测染毒人血清中的神经性毒剂沙林

采用了氟离子重活化-气相色谱质谱方法检测染毒人血清中的神经性毒剂沙林.优化了氟离子重活化体系并且考察了沙林的提取富集条件.根据丁酰胆碱酯酶活性恢复值得到其重活化效率可达到86%.在丁酰胆碱酯酶的活性抑制率6%～85%之间,此方法线性良好,检出限为4%的酶活性抑制率.该方法样品制备简单,血清样品干扰较小,是一种可用于确证沙林中毒的溯源性检测方法.     

压电晶体微天平阵列传感器识别毒剂的研究

压电晶体微天平(QCM)阵列传感器在毒剂侦检领域具有广泛的应用前景。本研究建立了QCM阵列传感器毒剂检测系统,以氢键酸性共聚硅氧烷(BSP3)、聚表氯醇(PECH)和乙基纤维素(ECEL)为膜材料制备了对毒剂敏感的QCM阵列传感器,对沙林、芥子气、甲基膦酸二甲酯进行了定量检测,并结合模式识别方法对检测结果进行了分析处理,识别率达到98%以上,为探索QCM阵列传感器对毒剂的定性定量分析提供了方法依据。     

Computational study toward understanding the photodissociation mechanism of sarin

The potential energy surface for sarin (C₄H₁₀FO₂P) dissociation into (CH₃)₂CHO+PO(F)(CH₃), CH₃+(CH₃)₂CHOPO(F), and F+(CH₃)₂CHOPO(CH₃) in the T₁ and S₁ states were investigated at the complete‐active‐space self‐consistent field (CASSCF) with the 6‐31G** and aug‐cc‐PVDZ basis sets. The different reaction pathways are characterized on the basis of the computed potential energy surface and surface crossing point, the time‐dependent density functional theory (TD‐DFT) was used to calculate the vertical energies based on the CAS(8,7)/6‐31G** optimized excited structures, which may provide some new insights into the mechanism of the ultraviolet photo‐degradation of sarin molecules. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011