가수분해 후 GC-ECD를 이용한 축산물 중 살균제 Prochloraz 및 그의 대사물의 동시분석

박지수 ( Ji-su Park ),최훈 ( Hoon Choi ) 한국응용생명화학회(구 한국농화학회) 2020 Journal of Applied Biological Chemistry (J. Appl. Vol.63 No.2

축산물 중 살균제 prochloraz 및 그의 대사체의 잔류량을 함께 정량분석할 수 있는 단성분 분석법을 개발하고자 하였다. 축산물 중 prochloraz의 잔류분의 정의가 ‘prochloraz와 2,4,6-trichlorophenol기를 포함하고 있는 대사산물의 합을 prochloraz로 함’이기 때문에 prochloraz 및 대사산물을 모두 2,4,6-trichlorophenol (2,4,6-TCP)로 분해시킨 후 GC/ECD로 정량하는 정밀 분석법을 확립하였다. 대표 축산물인 소고기, 돼지고기, 닭고기, 우유 및 계란 중 prochloraz 잔류분을 acetone으로 추출하고 2,4,6-TCP로 분해한 후 dichloromethane으로 분배하고 aminopropyl SPE로 정제한 다음 2,4,6-TCP를 정량하였다. 본 분석법을 통한 기기정량한계와 분석법정량한계는 prochloraz의 경우 각각 0.01 μg/mL과 0.02 mg/kg이었으며 2,4,6-TCP는 0.005 μg/mL과 0.01 mg/kg이었다. 2,4,6-TCP를 이용한 표준검량선은 0.005-0.2 mg/L 범위에서 결정계수(R²) ≥0.995으로 직선성을 확인하였다. 분석법의 회수율은 분석정량한계 및 정량한계의 10배 처리수준에서 실시하여 모두 90% 이상이었고 변이계수는 10% 이하이었다. 따라서, 본 연구에서 확립된 분석법은 축산물 중 prochloraz 및 대사체를 정량분석하는데 우수한 정확성 및 정밀도를 보였으며, 축산물 중 prochloraz 잔류분석을 위한 정밀시험법으로써 분석개발기준을 충족하였다. The analytical method was established for simultaneous determination of fungicide prochloraz and its metabolites in several animal commodities using gas chromatography (GC) coupled with electron capture detector (ECD). Samples including beef meat, pork meat, chicken meat, milk, and egg were hydrolyzed with pyridine hydrochloride which converts prochloraz and its metabolites to 2,4,6-trichlorophenol (2,4,6-TCP) because residue definition for prochloraz was ‘sum of prochloraz and its metabolites containing the 2,4,6-trichlorophenol moiety, expressed as prochloraz’, for compliance with MRLs from animal commodities. Therefore, residual prochloraz was extracted with acetone, decomposed to 2,4,6-TCP, partitioned with dichloromethane, purified with aminopropyl SPE and quantified as 2,4,6-TCP with GC-ECD. The instrumental limit of quantitation and method LOQ (MLOQ) was 0.01 μg/mL and 0.02 mg/kg for prochloraz and 0.005 μg/mL and 0.01 mg/kg for 2,4,6-TCP, respectively. The linearity of the calibration curve was good with R²>0.995 in the range of 0.005- 0.2 μg/mL. Fortification levels of prochloraz were 0.02 mg/kg (MLOQ) and 0.2 mg/kg (10MLOQ) for recovery tests. Overall recoveries of prochloraz were >90% with <10% of coefficient variation (C.V.). This established analytical method was fully validated and could be useful for quantification of prochloraz and its metabolites in animal commodities as official analytical method.

생약 길경(Platycodon Grandiflorum) 중 살균제 Prochloraz 분석법 개발

오경석 ( Gyeong-seok Oh ),양승현 ( Seung-hyun Yang ),윤명섭 ( Myung-sub Yun ),강동현 ( Dong-hyun Kang ),김민 ( Min Kim ),김재영 ( Jae-young Kim ),남근우 ( Gnu Nam ),최훈 ( Hoon Choi ) 한국환경농학회 2021 한국환경농학회 학술대회집 Vol.2021 No.-

Prochloraz 단성분 분석법은 이미다졸계 살균제인 prochloraz 및 그의 2,4,6-trichlorophenol moiety를 함유하는 대사산물을 분석대상으로 하였다. 대상 농약들은 환경이나 식물체내에서 구조가 변환되어 일반적으로 3개의 독성 대사물을 생산하는데, N-formyl-N-propyl-N-[2-(2,4,6- trichlorophenoxy) ethyl]urea와 N-propyl-N-[2-(2,4,6- trichlorophenoxy)ethyl]urea로 전환되고 이것은 다시 2,4,6-trichlorophenol로 분해된다. 현재 농산물 중 prochloraz의 잔류분 정의는 prochloraz와 2,4,6-trichlorphenol 기를 포함하고 있는 대사산물의 합을 prochloraz로 함으로써, 본 분석법의 모든 분석대상 화합물을 2,4,6-trichlorophenol으로 분해한 후 2,4,6-trichlorophenol로써 정량한 후 모화합물인 prochloraz로써 정량하도록 하였다. 해당 농약성분의 잔류시험법 확립을 위한 생약으로는 길경(Platycodon grandiflorum)을 사용하였다. 분석법의 경우 검체 5g에 습윤화 과정 이후 acetone을 첨가하여 분석 대상을 추출하였고, 추출액은 농축과정 없이 과량의 물과 혼합한 후 dichloromethane로 분배 회수한 후 prochloraz 대사체들을 분해하기 위하여 pyridine hydrochloride를 첨가하여 고온에서 분해하였다. 분해액을 이온억압분배법에 따라 분배하고 NH2 cartridge로 정제한 다음 GC/ECD로 분석하였다. Prochloraz 분석법 정량한계는 0.05 mg/kg을 목표로 설정하였으며, 이를 위해 prochloraz의 분해산물인 2,4,6-trichlorophenol의 ILOQ(Instrumental Limit of Quantitation, 기기상의 정량한계)는 S/N≥10을 만족하는 0.01 μg/mL이었으며 희석배수 2를 고려하여 분석법 정량한계(Method Limit of Quantification, MLOQ)는 2,4,6-trichlorophenol 0.02 mg/kg이다. 2,4,6-trichlorophenol의 ILOQ와 MLOQ를 prochloraz로써 환산할 경우 prochloraz의 ILOQ는 0.02 mg/kg이고 MLOQ는 0.04 mg/kg으로 분석법 개발기준을 만족하였다.

GC-ECD를 이용한 한약재 길경(Platycodi Radix) 중 살균제 Prochloraz의 분석

오경석 ( Gyeong-seok Oh ),윤명섭 ( Myung-sub Yoon ),양승현 ( Seung-hyun Yang ),최훈 ( Hoon Choi ) 한국환경농학회 2021 한국환경농학회지 Vol.40 No.4

본 연구는 한약재 길경 중 Imidazole계 살균제 prochloraz 및 그 대사체 2,4,6-T의 잔류분석법을 확립하였다. 한약재 중 길경을 대표 시료로 선정하고 GC-ECD를 이용한 prochloraz 정량 시험법을 개발하였다. 한약재 길경 중 prochloraz 잔류물을 acetone로 추출하고, dichloromethane로 분배하고 pyridine hydoxyde를 이용하여 분해한 뒤, 이온억압 분배과정 후, NH₂ cartridge로 정제하였다. 한약재 길경 중 prochloraz의 경우 정량한계는 0.04 mg/kg으로 결정되었으며, MLOQ 수준의 회수율은 89.7%, MLOQ 10배 수준에서는 82.5%의 우수한 회수율을 보였으며, 분석오차는 최대 2.8%로 재현성 역시 양호하였다. 2,4,6-T의 경우 정량한계는 0.02 mg/kg으로 결정되었으며, MLOQ 수준의 회수율은 83.0%, MLOQ 10배 수준에서는 82.1%의 우수한 회수율을 보였으며, 분석오차는 최대 2.8%로 재현성 역시 양호하였다. 본 연구에서 확립한 prochloraz 및 그 대사체 2,4,6-T의 잔류분석법은 국내·외 한약재의 잔류농약 검사 및 분석에 적용 가능할 것으로 기대된다. BACKGROUND: Prochloraz has been widely used as an imidazole fungicide on fruits and vegetables in Korea. Analytical approaches to evaluate prochloraz residues in herbal medicine are required for their safety management. In this study, we developed a GC-ECD method for quantitative determination of prochloraz in Platycodi Radix. The metabolite 2,4,6-trichlorophenol (2,4,6-T) was used as a target compound to evaluate total prochloraz residues as it is categorized to a representative residue definition of prochloraz. All residues containing 2,4,6-T were converted to 2,4,6-T and subjected to GC-ECD. METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining prochloraz and it metabolite 2,4,6-T in Platycodi Radix. Prochloraz and its metabolite 2,4,6-T residuals were extracted using acetone. The extract was diluted with and partitioned directly into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was decomposed to 2,4,6-T, and then the partitioned ion-associate was finally purified by optimized aminopropyl solid-phase extraction (SPE). The limits of quantitation of the method (MLOQs) were 0.04 mg/kg and 0.02 mg/kg, respectively for prochloraz and 2,4,6-T, considering the maximum residue level (MRL) of prochloraz as 0.05 mg/kg in Platycodi Radix. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (82.1-89.7%). Good reproducibilities were obtained (coefficient of variation < 2.8%), and the linearities of calibration curves were reasonable (r² > 0.9986) in the range of 0.005-0.5 μg/mL. CONCLUSION(S): The method developed in this study was successfully validated to meet the guidelines required for quantitative determination of pesticides in herbal medicine. Thus, the method could be useful to monitor prochloraz institutionally in herbal medicine.

Hydrodechlorination of 2,4,6-trichlorophenol for a permeable reactive barrier using zero-valent iron and catalyzed iron

김영훈,Jeong-Hak Choi,최상준 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.3

Dehalogenation of toxic organic compounds has been intensively studied during the last decade by using zero-valent iron (ZVI). However, the reactivity of iron is compound specific and very low reactivities were reported for aromatic compounds including chlorophenols. In this study, hydrodechlorination of 2,4,6-trichlorophenol (2,4,6- TCP) was conducted in a batch system by using ZVI and catalyzed iron. No degradation was observed with ZVI over the 40 days experiments. Catalyzed ZVIs removed 2,4,6-TCP and palladium-coated iron (Pd/Fe) and nickel-coated iron (Ni/Fe) showed relatively enhanced reactivity while copper-coated iron (Cu/Fe) and platinum-coated iron (Pt/Fe) showed lower reactivities. The surface area normalized kinetic constants (kSA) of Pd/Fe, Ni/Fe, Cu/Fe, Pt/Fe are 2.54× 10−4, 1.01×10−4, 2.24×10−5, 2.56×10−5 L m−2 h−1, respectively. The identification of less chlorinated phenols and phenol confirmed that the removal is dechlorination. Pd/Fe system exerts relatively low pH compared with the ZVI system, and the low pH is favorable for the dechlorination. The reactivity enhancement of catalyzed iron was discussed in terms of catalytic effects and the corrosion potential by the bimetal coupling. Variable Pd content on the Pd/Fe was tested, and the degradation rate of 2,4,6-TCP increased in proportion to the increase of Pd content.

Characterization and mechanism of the adsorptive removal of 2,4,6-trichlorophenol by biochar prepared from sugarcane baggase

S. Mubarik,A. Saeed,M.M. Athar,M. Iqbal 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Biochar from sugarcane baggase was prepared by heating at high temperature for 20 min. Surfaceproperties of the biochar were determined by Boehm titrations and FTIR. Biochar has 50.47% fixed carbonhaving methylene blue surface area of 361.77 m2/g. SEM image revealed that biochar has cylindrical,well shaped porous structures that increase surface area for adsorption. Operational parameters for2,4,6-TCP adsorption were optimized. The experimental qmax was found to be 253.38 mg/g. Biocharremoved 2,4,6-TCP in the presence of multiple pollutants. The functional moieties present on biocharshowed their affinity for 2,4,6-TCP 6¼ methylene blue > phenol > mercury.

Preparation and characterization of molecularly-imprinted magnetic microspheres for adsorption of 2,4,6-trichlorophenol from aqueous solutions

Ping Yu,Qilong Sun,Jianfeng Li,Zhenjiang Tan,Jianming Pan,Yongsheng Yan 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.4

Magnetic molecularly imprinted microspheres (MMIS) were successfully prepared by suspension polymerization,and then as-prepared MMIS were used as adsorbents for selective recognition of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. The results composites were characterized by Fourier transform infrared (FT-IR), X-raydiffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscope (SEM) and vibrating samplemagnetometer (VSM). The results demonstrated that MMIS possesses porous spherical morphology, and exhibits goodthermal stability and magnetic property (Ms=10.14 emu g−1). Then batch mode of binding experiments was used todetermine the equilibrium, kinetics and selectivity recognition. The Langmuir isotherm model fitted the equilibriumdata better than did the Freundlich model, and the maximum adsorption capacity on MMIS was about 1.7 times higherthan that of MNIS. Kinetics behaviors of MMIS were well described by the pseudo-second-order model. MMIS possessedoutstanding selectivity recognition for 2,4,6-TCP in the presence of other competitive phenols (such as sesamol,3-CP, thymol, 2,4-DCP). Furthermore, the reusability performance of MMIS showed about 17.53% loss after five repeatedcycles. Finally, the MMIS were successfully applied to the selective extraction of 2,4,6-TCP from the vegetablesamples.

감마선 처리에 의한 페놀과 2,4,6-트리클로로페놀의 분해제거 비교 연구

조훈제(Hun Je Jo),이선미(Sun Mi Lee),김정규(Jeong Gyu Kim),정진호(Jin Ho Jung) 大韓環境工學會 2004 대한환경공학회지 Vol.26 No.9

Fabrication of ZnO-doped reduce graphene oxide-based electrochemical sensor for the determination of 2,4,6-trichlorophenol from aqueous environment

Nawaz Muhammad,Shaikh Huma,Buledi Jamil A.,Solangi Amber R.,Karaman Ceren,Erk Nevin,Darabi Rozhin,Camarada Maria B. 한국탄소학회 2024 Carbon Letters Vol.34 No.1

Environmental pollution has become an alarming issue for the modern world due to the extensive release of untreated chemical waste into freshwater bodies. Untreated chemical waste poses significant negative impacts on aquatic life and human health. The phenolic compounds are widely used in different industries for dyeing, as food preservatives, and for the production of pesticides. 2,4,6-Trichlorophenol (TCP) is among the most hazardous phenolic compounds that cause several serious health effects. Thus, it is important to monitor TCP in the environmental samples frequently. In the current work, it was aimed to develop a highly sensitive zinc oxide-doped (ZnO) reduce graphene oxide (rGO) composite-based electrochemical sensor for TCP monitoring in the real samples. In this regard, graphene oxide (GO) was simultaneously reduced and doped with ZnO using a facile microwave-assisted synthesis strategy. The resulting ZnO/rGO composite was successfully utilized to fabricate ZnO/rGO-modified glassy carbon electrode (ZnO/rGO/GCE) for the selective and trace level determination of TCP. The conductivity and electrocatalytic behaviors of ZnO/rGO/GCE were examined through different modes of electrochemical setup. Under the optimal operating conditions such as a scan rate of 80 mV.s−1, PBS electrolyte (pH 7.0), and the concentration range of 0.01–80 µM, the fabricated electrochemical sensor manifested outstanding responses for monitoring TCP. The limit of detection (LOD) and limit of quantification (LOQ) of the ZnO/rGO/GCE for TCP were found as 0.0067 µM and 0.019 µM, respectively. Moreover, the anti-interference profile and stable nature of ZnO/rGO/GCE made the suggested electrochemical sensor a superb tool for quantifying TCP in a real matrix.

Fabrication of Cu2O/TiO2 nano-tube arrays photoelectrode and its enhanced photoelectrocatalytic performance for degradation of 2,4,6- trichlorophenol

Qiuling Ma,Huixuan Zhang,Yuqi Cui,Xiaoyong Deng,Ruonan Guo,Xiuwen Cheng,Mingzheng Xie,Qingfeng Cheng 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

Cu2O decorated TiO2 nano-tube arrays (Cu2O/TiO2 NTAs) photoelectrode was fabricated throughelectrodeposition strategy. Meanwhile, physicochemical properties of the resulting photoelectrode weresystematically studied by series of measurements. Results indicated that Cu2O/TiO2 NTAs photoelectrodeperformed a significantly enhanced light absorbance in the visible region between 400 and 800 nm,transient photocurrent density of 0.162 mA Cm 2, photogenerated charge separation efficiency and 99.9%of photoelectrocatalytic efficiency for decomposition of 2,4,6-trichlorophenol within 120 min Xenonillumination with the help of +1.0 V (vs. SCE) potential. Furthermore, the enhanced visible lightresponsible photoelectrocatalytic mechanism was proposed and discussed.

Treatment of wastewater containing organic pollutants in the presence of N‑doped graphitic carbon and Co3O4/ peroxymonosulfate

Hakkı T?rker Ak?ay,Adem Demir,Zehra ?z?if?i,Tu?rul Yumak,Turgut Kele? 한국탄소학회 2023 Carbon Letters Vol.33 No.5

The disposal of organic pollutants is one of the important research topics. Some of the studies in this field are based on the degradation of organic pollutants with a catalytic agent. The cobalt tetraoxide/peroxymonosulfate system is an important catalytic system used for the radical degradation of organic pollutants. To increase the catalytic efficiency of such reactions, graphitization of activated carbon used as a support solid and nitrogen doping to the carbon structure are commonly used methods. In this study, cobalt tetraoxide production, N-doping and graphitization were carried out in a single step by heat treatment of activated carbon doped with the phthlocyanine cobalt (II) complex. The catalytic performance of the catalyst/ peroxymonosulfate system was investigated by changing the pH, catalyst, and PMS concentration parameters on rhodamine B and 1,3,5 trichlorophenol, which were used as models. It was seen that the catalysts had 97% activity on rhodamine B in 16 min and 100% on 1,3,5 trichlorophenol in 6 min. It was observed that the catalysts continued to show high catalytic activity for five cycles in reusability studies and had a very low cobalt leaching rate. These results are in good agreement with previously published studies. In line with these results, the synthesized N-doped graphitic carbon/Co3O4 catalyst can be used as an effective catalyst for wastewater treatments.