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Jin-Woo Park(박진우),Kyung-Mi Moon(문경미),Young-Whan Choi(최영환),Young-Guen Lee(이영근) 한국생명과학회 2010 생명과학회지 Vol.20 No.1
파속류에 다량 함유된 황화합물들은 GC/ECD에 민감하게 반응하기에, 이 농산물들의 잔류농약분석에서 방해 물질로 작용하여 농약성분의 분리정량에 어려움을 주고 있다. 최근 잔류농약분석에서 정제법으로 여러 가지 고상추출법(solid-phase extraction)이 개발되고 있으며, 본 연구에서는 황화합물을 효율적으로 제거하기 위하여, 20% 질산은(AgNO₃)용액 3 ml을 Florosil cartridge (1 g packing, 6 ml tube)에 처리한 은이온흡착 cartridge (silver nitrate impregnated florosil cartridge)를 조제하였다. 이 cartridge를 이용하여 파속류 각 2, 4, 6 및 10 g에 해당하는 추출액을 고상추출법으로 정제한 결과, 양파 6 g, 대파 4 g, 쪽파는 4 g 까지는 황화합물의 95% 이상을 제거할 수 있었다. 그리고, 40종의 농약을 각 파속류에 첨가하고 이 cartridge에서 유출하여 회수율을 분석한 결과 34종이 70~120%의 범위 안에 들었다. Since organic sulfur compounds respond to GC/ECD sensitively, they interfere with quantitative separation of pesticides during residual pesticide analysis of Allium species. In this study, it was intended to develop a rapid and simple method for pesticide multi-residues analysis through clean-up and interferences by a solid-phase extraction (SPE). An SPE method employing silver nitrate impregnated Florosil cartridge was developed and evaluated for the elimination of sulfur compounds from the test solution of Allium species during pesticide residues analysis. The silver nitrate impregnated Florosil cartridge was prepared by efflux of 3 ml of 20% silver nitrate solution through Florosil cartridge (1 g packing, 6 ml tube). The extracts equivalent to 2, 4 6, and 10 g of each sample were loaded onto the cartridge and allowed to exude, and then the exudations were analyzed by GC/ECD. More than 95% of sulfur compounds were removed from the loaded extracts equivalent, up to 6 g in onion, 4 g in spring onion and 4 g in shallot, respectively. 40 pesticides were spiked in the Allium species and loaded onto the cartridge to determine the recoveries; from this, the recoveries of 34 pesticides were within 70~120%.
Effects of regeneration conditions on sulfated CuSSZ-13 catalyst for NH3-SCR
Meiqing Shen,Zhixin Wang,Xinhua Li,Jiaming Wang,Jianqiang Wang,Chen Wang,Jun Wang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.8
To understand the role of regeneration conditions on sulfur-poisoned Cu/SSZ-13 catalysts for NH3-SCR, the physicochemical characterizations and NOx conversions were investigated. The sulfur-poisoned Cu/SSZ-13 catalysts were treated at different conditions as a function of temperature and duration. TGA results revealed that regeneration at 500 oC only removed parts of sulfur spices and at 700 oC can completely remove all sulfur spices. The physical structural characterizations results illustrate that regeneration below 700 oC has no significant impact on CHA structure for Cu/SSZ-13 catalysts, while dealumination occurs on poisoned Cu/SSZ-13 when regeneration temperature is higher than 700 oC. EPR and H2-TPR results show that the sulfate decomposition and Cu migration reactions involved during regeneration and, as a result, the content of Cu2+ gradually increased as the extent of regeneration increased. The kinetics tests support that NOx conversion recovery is related to the content of Cu2+ increase during regeneration. Our study reveals that the optimum regeneration temperature is 700 oC, because severe dealumination at 750 oC inhibited Cu2+ amount increase.
The Relationship Between SO2 Exposure and Plant Physiology: A Mini Review
이현경,우수영,Inkyin Khaine,곽명자,장지휘,이태윤,이종규,김이레,김원일,오경석 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.6
Air pollutants are emitted from various sources into the atmosphere. During winter, greenhouses are heatedby the burning of fuel in heating systems, which creates sulfur dioxide (SO2) that can be detrimental to plant growthand human health. However, there is a poor understanding of the comprehensive effects of SO2 on crops in agreenhouse environment. Therefore, this review aimed to summarize the impacts of greenhouse heating system-derivedSO2 on the physiological, morphological, and biochemical responses of plants. In general, plant SO2 exposure has anegative effect on these processes. An initial decline in physiological activities appears several days following SO2exposure. Morphological and biochemical activities are also negatively affected by extensive SO2 exposure. However,since sulfur is an essential nutrient for plant growth, low-level SO2 exposure has a positive impact on plants. AtmosphericSO2 is taken up by the plant via the stomata, after which it is assimilated and used to synthesize sulfur-containingamino acids, such as methionine and cysteine. Sulfur-containing compounds are crucial for plant growth, and variousphysiological and biochemical processes. It was concluded that SO2 is a significant greenhouse pollutant, especiallyfor crops.
Precursor effect on catalytic properties of Mo-based catalyst for sulfur-resistant methanation
Haiyang Wang,Xinbin Ma,Zhenhua Li,Baowei Wang,Shaodong Qin,Shouli Sun,Qi Sun 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.12
The catalytic activity of Mo-based catalysts prepared from (NH4)6Mo7O24 and (NH4)2MoS4 was com-pared in the sulfur resistant methanation process. The catalyst using oxide precursor had relatively higher activity thanthe catalyst using sulfide precursor, and the presulfidation procedure almost had no effect on the catalytic performanceof the catalyst using oxide precursor. In view of the characterization results, it could be supposed that the amorphousMoS2 was more active for sulfur-resistant methanation than the crystalline MoS2. The molybdenum sulfides and oxideswith lower valence states (Mo4+, Mo5+) could be responsible for the catalytic activity and make a possible contributionto the carbon monoxide methanation in the reaction condition.
( Sae Yong Hong ),( Hyo Wook Gil ),( Jong Oh Yang ),( Eun Young Lee ),( Hyung Kee Kim ),( Soo Hyun Kim ),( Young Ho Chung ),( Eun Mi Lee ),( Soo Kyung Hwang ) 대한내과학회 2005 The Korean Journal of Internal Medicine Vol.20 No.3
Background: The purpose of this study was to determine the adequate loading and maintenance doses of N-acetylcyseteine (NAC) for patients suffering from acute ROS-induced injury. Methods: Concentrations of extra cellular NAC, cysteine (Cys), cystine (Cyst2), and methionine (Met) were measured in vitro, at which more than 50% of the intracellular ROS raised by paraquat were suppressed using Swiss 3T3 fibroblasts. An in vivo pharmacokinetic study followed on a healthy subject to determine the proper loading and maintenance doses of reduced NAC following intravenous administration of 25mg/kg NAC. Results: In vivo, NAC suppressed ROS in a dose dependant manner. 10mM of NAC suppressed about 50% of ROS, and was comparable to 10μM of Cys and Met and 400μM of Cys2. In vitro, the elimination of half life was achieved at 2.88±1.14 h for NAC and at 3.68±1.84 h for total NAC. The body clearances were 1.23±0.77 L h(-1) kg(-1) and 0.56±0.27 L h(-1) kg(-1) and the volumes of distribution were 3.07±0.10 L kg(-1) and 3.00±0.11 L kg(-1), respectively. The loading and maintenance NAC doses used to reach the target concentration of 10mM, were 5010mg. kg(-1) and 2250 mg min(-1) kg(-1), respectively Conclusion: NAC provides an antioxidant effect on ROS produced by paraquat in vivo. However, in vitro, our results showed that the intravenous NAC dose could not be estimated from NAC plasma concentration or its metabolites.
Chun-Yin Lau,Jianyu Guan,Ho-Yin TSE,Chi Shun Yeung,Chiu Wing Shum,Shao-Yuan Leu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.5
Sulfide control is a vital issue affecting the regional air quality and operational safety in sewage treatment processes. The conventional sulfide removal techniques are sophisticated industrial processes which require large operational footprint or are related to hazardous chemicals. In this study, the performance of elemental sulfur recovery from a simple micro-aeration process with metal-TCPP ((5,10,15,20)-tetrakis-p-carboxyphenylporphyrin) was investigated through laboratory experiments. A minimum of fourfold enhancement of elemental sulfur recovery was achieved from sulfide dissolved wastewater with the addition of nickel (II) TCPP, which demonstrated the highest among seven various types of transition metal-porphyrin complexes in the 3d block elements. The optimized reaction conditions resulted in 72.53% sulfur recovery with the addition of only 4.5 ppm nickel into the solution. The catalyst significantly improves the recyclability and life-cycle of the water-based absorbent and provides benefits to odor control and resource recovery.
Adaptive Responses to Electrophilic Stress and Reactive Sulfur Species as their Regulator Molecules
Kumagai, Yoshito,Akiyama, Masahiro,Unoki, Takamitsu Korean Society of ToxicologyKorea Environmental Mu 2019 Toxicological Research Vol.35 No.4
We are exposed to numerous xenobiotic electrophiles on a daily basis through the environment, lifestyle, and dietary habits. Although such reactive species have been associated with detrimental effects, recent accumulated evidence indicates that xenobiotic electrophiles appear to act as signaling molecules. In this review, we introduce our findings on 1) activation of various redox signaling pathways involved in cell proliferation, detoxification/excretion of electrophiles, quality control of cellular proteins, and cell survival during exposure to xenobiotic electrophiles at low concentrations through covalent modification of thiol groups in sensor proteins, and 2) negative regulation of reactive sulfur species (RSS) in the modulation of redox signaling and toxicity caused by xenobiotic electrophiles.
Adaptive Responses to Electrophilic Stress and Reactive Sulfur Species as their Regulator Molecules
Yoshito Kumagai,Masahiro Akiyama,Takamitsu Unoki 한국독성학회 2019 Toxicological Research Vol.35 No.4
We are exposed to numerous xenobiotic electrophiles on a daily basis through the environment, lifestyle, and dietary habits. Although such reactive species have been associated with detrimental effects, recent accumulated evidence indicates that xenobiotic electrophiles appear to act as signaling molecules. In this review, we introduce our findings on 1) activation of various redox signaling pathways involved in cell proliferation, detoxification/ excretion of electrophiles, quality control of cellular proteins, and cell survival during exposure to xenobiotic electrophiles at low concentrations through covalent modification of thiol groups in sensor proteins, and 2) negative regulation of reactive sulfur species (RSS) in the modulation of redox signaling and toxicity caused by xenobiotic electrophiles.