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농산물 중 잔류농약 시험법의 매질보정 검량법의 대표시료 탐색 연구
허장현 ( Jang-hyun Hur ),조영주 ( Yeong-ju Jo ),최정윤 ( Jeong-yoon Choi ),함헌주 ( Hun-ju Ham ),최재웅 ( Jae-woong Choi ),허경진 ( Kyung-jin Hur ) 한국환경농학회 2022 한국환경농학회 학술대회집 Vol.2022 No.-
최근 간편하고 신속한 QuEChERS 추출법과 질량분석기를 이용하는 분석법이 보편화됨에 따라 잔류농약 분석 시 비의도적 간섭물질로 인해 유발되는 농산물의 매질효과(matrix effect)에 관한 관심이 증가하고 있다. 매질효과(matrix effect)는 주로 질량분석기로 분석하는 과정에서 시그널 억제(suppression) 또는 시그널 증가(enhancement)와 같은 현상으로 나타난다. 이러한 현상은 매질별로 상이하게 나타나고 분석성분의 감도 변화에도 큰 영향을 미쳐 정량분석 업무에 어려움을 준다. 일선 분석 현장에서는 시료별 매질효과(matrix effect)를 최소화하고자 동일한 시료를 활용하는 매질보정(matrix matched) 방법을 활용하고 있으나 모든 농산물 시료마다 모든 바탕시료(matched matrix)를 준비하기에는 한계가 있다. 본 연구는 다소비 농산물을 선정하여 식약처 ‘다성분 시험법-제2법’ 분석 시 매질효과 특성을 살펴보고 이를 바탕으로 대표매질 선정을 위한 탐색 가능성을 모색하기 위하여 도출되었다. 우선 식물성 원료 7종 중 곡류(6품목), 서류(3품목), 두류(4품목), 견과 종실류(5품목), 과일류(11품목), 채소류(17품목), 버섯류(4품목)의 다소비 식품 50품목을 선정하여 현행 분석법으로 정량 가능한 460여 종 다성분 잔류농약에 대한 농산물별 매질효과를 산출하였다. 분석대상 농산물은 시중에서 구매한 후 사전 실험을 통해 식약처 ‘다성분 시험법-제2법’ 분석에서 잔류농약이 검출되지 않는 농산물을 사용하였다. 매질효과 평가를 위한 실험은 잔류농약 510종 중 정량 가능한 460여 종을 LC와 GC-MS/MS를 사용하여 정량하여 용매표준용액의 검량선과 매질표준 용액의 검량선을 비교하여 매질효과(%)를 산출하였다. 산출된 matrix effect 범위는 soft (≤±20%), medium (±20%< ME≤±50%), strong ( >±50%) range로 구분하였으며, soft range는 정량성을 확보할 수 있는 국제적 기준으로 판단하였다. 현재까지 결과는 LC-MS/MS 분석은 45품목, GC-MS/MS 분석은 32품목이 완료되어 일부 시료에 대한 매질효과를 평가하였다. 평가 결과 매질효과(%)는 ±20% 이내 soft range 매질효과를 보이는 성분 수가 LC-MS/MS는 245성분 중 곡류, 서류, 두류, 견과종실류, 버섯류에서 204∼245성분(83.3∼100.0%), 과일류와 채소류는 115∼241성분(46.9∼98.4%)이었다. GC-MS/MS는 261성분 중 곡류, 서류, 두류, 견과종실류, 버섯류에서 211∼247성분(80.8∼94.6%), 과일류와 채소류는 192∼238성분(73.6∼91.2%)이었다. 특히 과일류와 채소류 농산물 중 LC-MS/MS 분석에서 딸기, 마늘, 양파, GC-MS/MS 분석에서 커피원두, 수박, 배추, 시금치, 마늘에서 상대적으로 높은 수준의 매질효과가 관찰되었다. 본 연구 결과를 바탕으로 그룹별, 성분별 매질효과를 상호 비교하여, 향후 대체 또는 대표매질 선정 가능성을 평가하고자 한다.
Apoplastic Phloem Loading of Photoassimilate
김성문,허장현,한대성,Kim, Song-Mun,Hur, Jang-Hyun,Han, Dae-Sung 한국잡초학회 1997 Weed&Turfgrass Science Vol.17 No.4
Photoassimilates translocate from regions of carbohydrate synthensis(source) to regions of carbohydrate utilization or storage(sink). In the source, assimilate loads into the phloem for long-distance transport. Current evidence suggests that there are twig loading mechanisms : one involves assimilate transfer via the apoplasm and then load into the phloem by carrier-mediated proton-sucrose cotransport, while the other involves movement through the continuous symplastic connections between the mesophyll cells and the phloem. Inspite of problems associated with the interpretation of experiments, the evidence for apoplastic loading remains convincing because the apoplastic loading systems explains well the observed accumulation capacity arid the selectivity of assimilate uptake by tile phloem.
이서래,이해근,허장현 ( Su Rae Lee,Hae Keun Lee,Jang Hyun Hur ) 한국환경농학회 1996 한국환경농학회지 Vol.15 No.1
The usage level of pesticides in Korea reached the relatively high extent of 13 ㎏ a.i./㏊ for arable land, and therefore, establishment of legal standards on pesticide residues in soil environment has been requested. This paper presents relevant information on soil contamination and proposes tentative standards on 20 pesticides in agricultural, urban and forest soils, respectively, as well as needed background data to support the justification of the standards.
Phosalone 의 활성화과정을 통한 acetylcholinesterase 와 butyrylcholinesterase 에 대한 활성 저해
임금춘(Geum Choon Lim),허장현(Jang Hyun Hur),한대성(Dae Sung Han) 한국응용생명화학회 1995 Applied Biological Chemistry (Appl Biol Chem) Vol.38 No.2
The purpose of this study was to investigate a role of cytochrome P_(450), for the toxicity of the phosalone in in vitro and in vivo bioactivation systems. The bimolecular inhibition rate constants(k_i) of the phosalone to acetylcholinesterase(AChE) and butyrylcholinesterase(BuChE) were approximately 10²M^(-1)min^(-1), respectively, which meant a poor inhibitor. The potency of the phosalone as an inhibitor of AChE and BuChE was increased about 300 and 40 fold, respectively, when the inhibitor and the ChE were incubated with microsomes fortified with NADPH compared with microsome alone. Piperonyl butoxide(PB) addition to these coupled systems greatly reduced the inhibition of both target enzymes by blocking a bioactivation process. The I_(50), value of the Phosalone alone for rat brain AChE was 170 ㎎/㎏. When PB was pretreated, that value was altered to 42.5 ㎎/㎏. PB pretreatment synergized the inhibition of brain AChE with four times. Rat blood erythrocyte AChE and plasma BuChE were similarly inhibited in vivo by the phosalone and PB pretreatment didn`t affect significantly the pattern of the inhibition. The in vivo studies showed different results in the role of cytochrome P_(450) from those of the in vitro studies.
방울토마토(Lycopersicon esculentum Mill.) 생산단계에서 Fluopicolide 및 Metrafenone의 잔류허용기준 설정
허경진 ( Kyung Jin Hur ),우민지 ( Min Ji Woo ),김지윤 ( Ji Yoon Kim ),( Manoharan Saravanan ),권찬혁 ( Chan Hyeok Kwon ),손영욱 ( Yong Wook Son ),허장현 ( Jang Hyun Hur ) 한국환경농학회 2015 한국환경농학회지 Vol.34 No.4
BACKGROUND: The present investigation was aimed to predict the pre-harvest residue limits (PHRLs) of the fluopicolide and metrafenone on cherry tomato and to estimate their half-life and characteristics of the residues.METHODS AND RESULTS: Pesticides were treated once on cherry tomato in field 1 and 2 under the standard application rate. The samples were collected 7 times at the end of 0(2 hours after pesticides spaying), 1, 2, 3, 5, 7 and 10 days before harvest. Residues of fluopicolide and metrafenone were analyzed by the LC-MS/MS. In this study, the method limit of quantification (MLOQ) for both fluopicolide and metrafenone in cherry tomato was found to be 0.005 mg kg-1. Their recovery levels were 92.7∼94.8% and 82.6∼88.0%, shown with coefficient of variation of less than 10%. Half-life of fluopicolide and metrafenone in field 1 and 2 were found to be 15.0 days and 12.8 days, 18.9 days and 21.5 days, respectively.CONCLUSION: Based on the results, this study shows the level of PHRL on cherry tomato is 0.27 mg/kg for fluopicolide and 2.29 mg/kg for metrafenone at 10 days before harvesting. The present study indicates the residues of both pesticides on cherry tomato will be below maximum residue limit (MRL) at harvest.
고구마뿌리혹선충(Meloidogyne incognita)에 대한 국내 자생식물의 살선충 활성
임상현(Lim Sang-Hyun),주영철(Yong Ze Zhu),김미성(Mi-Sung Kim),이유선(Yu-Sun Lee),손정식(Jeong-Sik Son),박동식(Dong-Sik Son),허장현(Jang-Hyun Hur),김희연(Hee-Yeon Kim),최해진(Hae-Jin Choi),김경희(Kyung-Hee Kim),김성문(Songmun Kim) 한국농약과학회 2004 농약과학회지 Vol.8 No.4
Large economic losses have been reported by root-knot nematide, Meloidogyne incognita, in Korea. However, fewy environmentally-friendly nematicide alternatives for the control of M. incognita have been developed. This study was conducted of Korean native plants to screen nematicidal activity which could be used by organic farmers. Methanol extracts (1,000 ㎎ L?¹) from fifty-three Korean native plants were applied to 24-well tissue culture testplates containing 1 × 10² M incognita and the nematicidal activities were determined, Nematicidal activities of the methanol extracts in common purslain (Portulaca oleraceae L.) and water mouse-ear-chickweed (Stellaria aquatica Scop.) were 60.0% and 40.6%, respectively, compared with that of control, however, those of other forty-one plants were less than 30%. Our results suggest that the methanol extracts of common purslain and water mouse-ear-chickweed contain nematicidal active compounds.