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LC-MS/MS를 이용한 퇴비 및 액비 중 항생제 동시 분석법 개발
정형석,이영준,이한솔,박병준,김장억,심재한,Chung, Hyung Suk,Lee, Young Jun,Lee, Han Sol,Rahman, Md. Musfiqur,Kabir, Md. Humayun,Park, Byung-Jun,Kim, Jang-Eok,Shim, Jae-Han 한국환경농학회 2017 한국환경농학회지 Vol.36 No.3
전국의 퇴비 및 액비 시료에서 대상 항생제 종9 (ceftiofur, clopidol, florfenicol, sulfamethazine, sulfamethoxazole, sulfathiazole, tetracycline, tiamulin, tylosin)을 pH 6 McIlvaine buffer를 사용하여 아세트산 함유 아세토니트릴, $Na_2Cit.5H_2O$, $Na_3Cit.2H_2O$로 추출 후 $C_{18}$과 PSA로 정제하여 LC-MS/MS로 분석하는 모니터링을 수행하였다. 그 중 5종의 항생제 sulfamethazine, sulfathiazole, tylosin, tiamulin 및 clopidol이 국내 퇴액비 시료에서 검출되었으며 제안한 분석법은 퇴 액비 중 잔류 항생제 모니터링을 위한 빠르고 간편한 시험법이라 사료 된다. 본 실험을 통하여 퇴비 및 액비 중 축산 항생제의 잔류 현황을 파악하여 모니터링 자료를 확보하였고 이를 활용하여 검출된 항생제들이 안전한 토양 및 생태 환경 유지 및 관리의 기초 자료와 더불어 환경기준 예비 항목 및 설정(안)을 위한 기초자료로 제공 및 다양하게 활용될 수 있을 것으로 판단된다. BACKGROUND: The current study was to monitor of 9 veterinary antibiotics (ceftiofur, clopidol, florfenicol, sulfamethazine, sulfamethoxazole, sulfathiazole, tetracycline, tiamulin, and tylosin) in manure using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive and negative electrospray ionization mode. METHODS AND RESULTS: Sample preparation was carried out using Mcllvaine buffer and citrate salts to adjust the pH of the sample followed by purification with dispersive solid phase extraction (d-SPE). Separation of analytes during LC-MS/MS analysis was conducted using an Eclipse Plus $C_{18}$ column and the mobile phase was in gradient mode with, 0.1% formic acid and 5 mM ammonium formate in methanol (A) and 0.1% formic acid and 5 mM ammonium formate in distilled water (B). The linearity of the matrix-matched calibrations of all tested antibiotics was good, with $R^2$ determination coefficients ${\geq}0.9920$. The limit of detection (LOD) and quantifications (LOQ) were $0.1-67.0{\mu}g/kg$ and $0.4-200.0{\mu}g/kg$, respectively. Analysis of 13 solid and liquid manure samples taken from the Republic of Korea revealed concentrations less than $0.7{\mu}g/kg$ for tiamulin, $1497.6{\mu}g/kg$ for sulfamethazine. CONCLUSION: To monitor 9 veterinary antibiotics from manure samples in 13 provincial areas throughout the Republic of Korea, an analytical method was developed. The developed method was fully validated and successfully applied for monitoring various veterinary antibiotics in manure samples.
정형석 ( Hyung Suk Chung ),이한솔 ( Han Sol Lee ),무스픽 ( Musfiqur Rahman ),카빌 ( Humayun Kabir ),박병준 ( Byung-jun Park ),김장억 ( Jang-eok Kim ),심재한 ( Jae-han Shim ) 한국환경농학회 2017 한국환경농학회 학술대회집 Vol.2017 No.-
Veterinary antibiotics contaminate plants through manure, irrigation, and atmospheric interaction. The present study was conducted to estimate the half-life of three veterinary antibiotics, chlortetracycline (CTC), enrofloxacin (ENR), and sulfathiazole (STZ), in soil and experimentally explore their uptake from contaminated soil to radish roots and leaves. Samples were extracted using a modified citrate-buffered version of the quick, easy, cheap, effective, rugged, and safe “QuEChERS” method followed by liquid chromatography coupled with tandem mass spectrometric analysis (LC-MS/MS) in positive ion mode. Good linearity was observed for the three tested antibiotics in soil and plants (roots and leaves) with high determination coefficients (R2 34 ≥ 0.9922). The average recovery rates at two spiking levels with three replicates per level ranged between 77.1 and 114.8%, with a relative standard deviation (RSD) ≤ 19.9% for all tested matrices. In a batch incubation experiment (in vitro study), the half-lives of CTC, ENR, and STZ ranged from 2.0- 6.1, 2.2-4.5, and 1.1-2.2 days, respectively. Under greenhouse conditions, the half-lives of the three target antibiotics in soil with and without radishes were 2.5-6.9 and 2.7-7.4; 4.7-16.7 and 10.3-14.6; and 4.4-4.9 and 2.5-2.8 days, respectively. Trace amounts of the target antibiotics (CTC, ENR, and STZ) were taken up from soil via roots and entered leaves of radishes. The concentration of CTC was lower than 2.73%, ENR was 0.08-3.90%, and less than 1.64% STZ was absorbed. In conclusion, the concentrations of the tested antibiotics decreased with time and consequently lower residues were observed in radishes. The rapid degradation of the tested antibiotics in the present study probably might have a little impact on soil microorganisms, fauna, and plants.
반복하중을 받는 외부 보-기둥 접합부에 정착된 57mm 확대머리철근의 정착성능평가
정형석 ( Hyung-suk Jung ),정주홍 ( Joo-hong Chung ),최창식 ( Chang-sik Choi ),배백일 ( Baek-il Bae ),최현기 ( Hyun-ki Choi ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.6
본 연구에서는 반복하중을 받는 외부 보-기둥 접합부에 정착된 57mm 확대머리철근의 정착성능을 평가하였다. 총 4개의 외부 보-기둥 접합부 실험체를 계획하였으며, 콘크리트 압축강도, 측면피복두께, 횡보강근비 및 파괴유형을 주요 실험 변수로 설정하여 정착성능평가를 수행하였다. 성능평가 결과, 접합부에 정착된 대구경 확대머리철근의 정착성능에 가장 큰 영향을 주는 요소는 측면피복두께 및 횡보강근으로 나타났으며, 외부 보-기둥 접합부에 정착된 57mm 대구경 확대머리철근은 반복하중하에서도 충분한 정착성능이 발현되는 것을 확인할 수 있었다. In this study, the anchoring performance of 57mm headed bars anchored at the external beam-column joint under cyclic loading was evaluated. A total of 6 external beam-column joint test specimens were planned, and anchorage performance was evaluated by setting concrete compressive strength, side covering thickness, lateral reinforcement ratio, and fracture type as major experimental variables. As result of cyclic loading test, it was found that the factors that had the greatest influence on the anchoring capacity of the large-diameter headed bar anchored at the joint were the side cover thickness and the transverse reinforcing bar. It was confirmed that the 57mm large-diameter headed bar anchored at the external beam-column joint showed sufficient anchoring capacity even under cyclic loading.
정주홍 ( Chung Joo Hong ),정형석 ( Jung Hyung Suk ),최현기 ( Choi Hyun Ki ) 한국구조물진단유지관리공학회 2018 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.22 No.1
This paper presents the influence factors of heat transfer in a voided slab under fire situation. The effects of a void in a slab on heat transfer are presented and the results are quantitatively analyzed for each influence factor. For this purpose, the finite element analysis method was used to evaluate the influence of the heat transfer factors on the thermal characteristics in a voided slab. Based on these results, the influence factors which have significant difference in the temperature spectrum were derived.
LC-MS/MS를 이용한 배 중 티오파네이트메틸 및 대사체 동시 분석
이한솔 ( Han Sol Lee ),정형석 ( Hyung Suk Chung ),( Musfiqur Rahman ),( Humayun Kabir ),심재한 ( Jae-han Shim ) 한국환경농학회 2017 한국환경농학회 학술대회집 Vol.2017 No.-
Thiophanate-methyl is used as systemic fungicide with broad-spectrum activity, and is used to control various fungal pathogens such as Venturia nashicola and Glomerella cingulate in pear, apple, and paprika. Pear is one of the most common fruits in Republic of Korea and other Asian countries, and in 2016, it is the crop with the highest yields followed by apple and the production amounted to about 23,000 tons in Korea. In the open field, pear fruits can be easily attacked by plant pathogens at a suitable temperature. However it is difficult for farmers to maintain an environment such as temperature and humidity. For this reason, the application of pesticides should be considered to reduce workforce and cut losses in fruit production. For safety of consumers, an analytical method was developed to quantify the residual levels of the thiophanate-methyl and its metabolite in field-incurred pear samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted with methanol and clean-up with C18 QuEChERS bulk sorbent. Linearity of a matrix-matched calibration curve of the thiophanate-methyl and carbendazim over a concentration range of 0.005-0.5 μg/mL and 0.001-0.1 μg/mL, respectively, was excellent, with determination coefficients (R<sup>2</sup>) ≥ 0.9990. The limits of detection (LOD) and quantitation (LOQ) for thiophanate-methyl and carbendazim were 0.0015 and 0.005 mg/kg, and 0.0003 and 0.001 mg/kg, respectively. The average recoveries of two analyte at two spiking levels (10 × LOQ and 50 × LOQ) were between 75.00 to 84.92%, with relative standard deviations (RSDs) ≤ 5.78%. The method was successfully applied to field-incurred samples treated with a commercial pesticide product. The treatments were divided into four treatments according to the days before harvest and sprayed four times following schedule: (treatment 1) 70, 60, 50 and 40 days before harvest; (treatment 2) 60, 50, 40 and 30 days before harvest; (treatment 3) 50, 40, 30 and 21 days before harvest; (treatment 4) 40, 30, 21 and 14 days before harvest. The highest and lowest residues were obtained for treatment 4 and treatment 2, respectively. The developed method is simple and accurate and can be extrapolated to other fruits.
LC-MS/MS를 이용한 축산물 중 spinosad의 분석법 개발
( Musfiqur Rahman ),( Abd El Aty ),정형석 ( Hyung Suk Chung ),( Humayun Kabir ),이한솔 ( Han Sol Lee ),심재한 ( Jae-han Shim ) 한국환경농학회 2017 한국환경농학회 학술대회집 Vol.2017 No.-
A simple and effective method was developed for analysis of spinosad (spinosyn A and spinosyn D) in five animal origin products (chicken, pork, beef, table egg, and milk) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample was extracted with acetonitrile and salt and purified via dispersive solid phase extraction (d-SPE) procedure using multi-walled carbon nanotubes (MWCN). The limits of quantification (LOQ) were maintained ten times lower than the maximum residue limits (MRL) followed by Codex guideline and were ranged between 0.001 and 0.1 mg/kg. Seven points matrix matched external calibration curves were prepared for each of the matrices and good linearity was observed with determination coefficients (R<sup>2</sup>)≥0.997. Method was validated in triplicate with three fortification levels at LOQ, 2LOQ and 10LOQ. A good recovery was observed for each of the fortification levels and was ranged between 73.84 and 103.60% with relative standard deviation (RSD) ≤ 9.68. The method can be extrapolated to other matrices for routine analysis of spinosad in livestock products or other matrices.
근대 중 Dimethomorph의 잔류 양상 및 위해성 평가
( Humayun Kabir ),( Musfiqur Rahman ),( Abd El-aty ),정형석 ( Hyung Suk Chung ),이한솔 ( Han Sol Lee ),심재한 ( Jae-han Shim ) 한국환경농학회 2017 한국환경농학회 학술대회집 Vol.2017 No.-
The residue analysis of dimethomorph in Swiss chard cultivated at two different locations under plastic house conditions were carried out using liquid chromatography-ultraviolet detector (LC-UVD). The LC-UVD result was confirmed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The sample was collected randomly over 14 days. The sample extracted using acetonitrile and partitioning by solid liquid extraction using 15 g NaCl, for cleanup florisil solid phase extraction (SPE) cartridge was used. The standard showed excellent linearity in the range (0.05-50.0 mg/L) with correlation coefficient (R<sup>2</sup>=0.9996), and the recovery ranged from (82.98-95.43%) with relative standard deviaton (RSD) less than 5.12% and the limit of detection and quantification was 0.0033 and 0.01 mg/kg respectively. The initial (0 day) residue amount was 7.57 and 8.55 mg/kg for site 1 and site 2 respectively. The dissipation half life was 5.0/5.1 days for site 1/site2. Pre harvest residue limit (PHRL) curve showed if the residue amount below 50.14/49.83 mg/kg 5 days before harvest and below 83.81/82.27 mg/kg 10 days before harvest then the residue will be below the maximum residue limit (MRL) 30.0 mg/kg during the harvest. The risk assessment considering the experimental conditions and Korean peoples diet habits, the accepted daily intake (ADI)% at 0 days sample 0.084/0.094% and at 10 days sample 0.014%. The lowe ADI % showed the safety of uses of this pesticide on Swiss chard and these data may be useful to recommend for the use of this pesticide on some similar vegetables.