• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.172-177
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• 2007

The hydrolysis reaction of sarin(GB), one of the nerve agents was studied in aqueous sodium hydroxide(NaOH) solutions to find the experimental conditions which can convert GB into the less toxic compounds. 10 wt% of GB was added into the aqueous NaOH(2.05 eq) in a small-scale jacket-attached reactor connected to a circulator. The reaction rate constants were measured at three temperatures(50, 70 and $90^{\circ}C$) and the reaction times required to degrade the material to > 99% were calculated at different temperatures. In this study, 10 wt% of GB was degraded to 99.99% in 1.2hr at $90^{\circ}C$ by the aqueous NaOH solution. The major hydrolysate of GB was isopropyl methylphosphonate.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.164-175
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• 2000

Three compounds of Cu(II)-loaded N,N,N'-trimethylethylenediaminated Merrifield-type polymers were synthesized with yields higher than 80%, and the hydrolysis reaction rates of O-isopropylmethyl-phosphonofluoridate(GB) and O-pinacolylmethylphosphonofluoridate (GD) catalyzed by them have been surveyed. GB and GD hydrolysis by Cu(II)-loaded polymers occurs via intermediate complex mechanism where rapid equilibrium to form intermediate complex between substrate and Cu(II)-loaded polymers($K_f$) is followed by rate determining hydrolysis step($k_1$). The measured activation parameters for $k_1$ are ${\Delta}H^{\ddag}$ : $17.75{\pm}0.98kJ/mol$ ${\Delta}S^{\ddag}$ / : $-218.42{\pm}3.35J/mol$ K, $E^{\circ}_a$ : $20.22{\pm}0.98kJ/mo1$ for GB and ${\Delta}H^{\ddag}$ / : $11.16{\pm}1.15kJ/mol,$${\Delta}S^{\ddag}$ /: $-258.57{\pm}3.93J/mol$ K, $E^{\circ}_a$ : $13.64{\pm}1.15 kJ/mol$ for GD. Standard enthalpy/entropy changes corresponding to the intermediate complex formation constant $K_f$ are ${\Delta}H^{\circ}$ : $37.05{\pm}2.19 kJ/mo1,$$ {\Delta}S^{\circ}$ : $163.12{\pm}7.49 J/mol$ K and ${\Delta}H^{\circ}$ : 418.59{\pm}2.04 kJ/mol,$ ${\Delta}S^{\circ}$ : 4111.92{\pm}6.98 J/mol$ K for GB and GD, respectively, The electron push-pull mechanism by Cu(II)-loaded polymers lowers the P-F bond breaking energy(~400 kJ/mol) to less than 1/20 compared to the case in which no Cu(II)-loaded resin presents. Analysis of $K_f$ and 4k_1$ over pH=6.5~8.0 range suggest that the GB and GD hydrolysis occurs intramolecularily with $pK_a$ =7.29 for ligated $H_2O$ and $t_{1/2}$=36.9 sec, $pK_a$ = 7.06 and $t_{1/2}$=177.7 sec for GB and GD, respectively.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.115-116
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• 2013

본 연구에서는 유기인 유도체 중 생리활성이 커서 독성이 있는 화합물의 구조를 분석하였다. 5-[(b-monoaza-15-crown-5)ethyloxy]-2iodosbenzoic acid의 IBA 촉매를 합성하여 그 반응성을 p-nitrophenyldiphenylphosphate (PNPDPP)와 Isopropyl methylphosphonofluoridate (Sarin GB), Pinacolyl methylphosphonofluoridate (Soman, GD)를 기질로 하여 연구하였다. PNPDPP 가수분해 반응에서는 긴 알킬작용기로 친유성을 증가시킨 촉매가 더 상전이 촉매로 작용함이 확인되었다.(t1/2 = 5 sec, pH = 8.07)

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.123-129
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• 2007

A 2-step process for the safe destruction of chemical wafare agents(agent hydrolysis followed by supercritical water oxidation) was studied to obtain kinetic data for the pilot plant design. This process is simple to operate by using commercial equipments and could be applied as an alternative technology to incineration. Sarin(GB) and sulfur mustard(HD) were hydrolysed in sodium hydroxide and water respectively and their hydrolysates and OPA, which is binary agent for GB were oxidized in a continuous flow supercritical water oxidation system. Destruction efficiencies of the materials were above 99.99% in supercritical water.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.133-140
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• 2008

The purpose of this study is to provide response methods to minimize the damage from chemical terrorism in a naturally ventilated indoor system using several types of dispersion simulations. Three chemical warfare agents such as sarin(GB), phosgene and chlorine gas which have high potential to be used in terror or to be involved with accidents were selected in this simulation. Fire dynamic simulation based on Large Eddy Simulation which is effective because of less computational effort and detailed expression of the dispersion flow was adopted to describe the dispersion behavior of these agents. When the vent speed is 0.005m/s, the heights of 0.1 agent mass fraction are 0.9m for sarin, 1.0m for phosgene and 1.1m for chlorine gas, and the maximum mass fraction are 0.27 for all three agents. However, when the vent speed is increased to 0.05m/s, the heights of 0.1 agent mass fraction become 1.6m for all three agents and maximum mass fraction inside the room increase to 0.70 for sarin, 0.58 for phosgene and 0.53 for chlorine gas. It is shown that molecular weight of the agents has an important role for dispersion, and it is important to install ventilation system with height less than 1.6m to minimize the damage from chemical toxicity.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.116-122
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• 2007

A 2-step process for the safe disposal of chemical warfare agents(agent hydrolysis followed by incineration In the submerged-quench incinerator) was studied to obtain basic data for the design of pilot plant in the future. Sample materials used for the hydrolysis reaction were sarin(GB), sulfur mustard (HD), and methylphosphonic difluoride(DF). The hydrolysates of these materials were thermally destroyed in a submerged-quench incineration system. Experimental conditions for achieving destruction efficiency of 99.99% in both steps were established and phosphoric acid was recovered from the waste water when destroying DF hydrolysate in the incinerator. Treated water could be reused as process water for the agent hydrolysis.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.17-22
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• 2015

International interests in chemical warfare agents (CWAs) have been increased recently because of the use of sarin (GB) in Syrian civil war which caused around 1,300 casualties in 2013. After exposing to natural environments, CWAs undergo hydrolysis or photodegrade to non-toxic degradation byproducts. Generally, CWAs and their degradation byproducts are present at very low concentration (e.g. several ppb), thus pretreatment processes including separation, extraction and concentration are required prior to any analyses. Liquid-liquid extraction and solid-phase extraction (SPE) are common techniques to pretreat environmental samples. Recently, a novel pretreatment method, liquid phase miecoextraction (LPME), has been applied to CWAs analysis, which could reduce amounts of solvent used but promote analytical efficiencies. Fundamental backgrounds of LPME and its application to CWAs analysis were reviewed.