LC-MS/MS를 이용한 농산물 중 식물생장조절제 Trinexapac-ethyl과 대사산물 Trinexapac의 동시분석법 개발

장진 ( Jin Jang ),김희정 ( Hee Jung Kim ),고아영 ( Ah Young Ko ),이은향 ( Eun Hyang Lee ),주윤지 ( Yun Ji Ju ),장문익 ( Moon Ik Chang ),이규식 ( Gyu Seek Rhee ),서세정 ( Sae Jung Suh ) 한국환경농학회 2015 한국환경농학회지 Vol.34 No.4

BACKGROUND: Trinexapac-ethyl is a plant growth regulator (PGR) that inhibits the biosynthesis of plant growth hormone (gibberellin). It is used for the prevention of lodging, increasing yields of cereals, and reducing mowing of turf. The experiment was conducted to establish a determination method for trinexapac-ethyl and its metabolites trinexapac in agricultural products using LC-MS/MS.METHODS AND RESULTS: Trinexapac-ethyl and trinexapac were extracted from agricultural products with methanol/distilled water and the extract was partitioned with dichloromethane and then detected by LC-MS/MS. Limit of detection(LOD) was 0.003 mg/kg and limit of quantification(LOQ) was 0.01 mg/kg, respectively. Matrix matched calibration curves were linear over the calibration ranges (0.01-1.0 mg/L) for all the analytes into blank extract with r2 > 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, 50LOQ, n=5). Recoveries of trinexapacethyl and trinexapac were within the range of 73.6-106.9%,72.7-99.2%, respectively. The relative standard deviations (RSDs) were less than 9.0%. All values were consistent with the criteria ranges requested in the CODEX guideline(CAC/GL 40, 2003).CONCLUSION: The proposed analytical method was accurate, effective and sensitive for trinexapac-ethyl and trinexapac determination and it can be used to as an official method in Korea.

HPLC-UVD를 이용한 농산물 중 Imazapyr의 공정분석법 확립

장진(Jin Jang),김희정(Heejung Kim),고아영(Ah-Young Ko),이은향(Eun-Hyang Lee),주윤지(Yoon Ji Joo),김진홍(Jinhong Kim),장문익(Moon-Ik Chang),이규식(Gyu-Seek Rhee) 한국농약과학회 2015 농약과학회지 Vol.19 No.1

A chromatographic method for the determination of imazapyr, a non-selective herbicide, in agricultural commodities was developed to use safety control of pesticide residue on crops, and was fully validated as an official method for residue analysis. Agricultural commodities, mandarin (fruit), hulled rice (cereal grains), pepper (vegetables), potato (potatoes) and soybean (beans) were extracted with methanol and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2.5 by 4N hydrochloric acid. Finally, they were analyzed by high performance liquid chromatography coupled to UV detector (HPLC-UVD). The developed method had the linearity in the range of test concentrations with coefficients of determination (r<SUP>2</SUP>) more than 0.99. Recovery studies were carried out at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. Recoveries were ranged between 72.1 to 108.0%, with relative standard deviations less than 10%. A consistent recovery was determined according to the CODEX guidelines (CAC/GL40, 2003). Finally, LC/MS with selected ion monitoring was also applied to confirm the suspected residues of imazapyr in agricultural samples. This developed method for determination of imazapyr residues in agricultural commodities. can be used as an official method.

GC-ECD를 이용한 농산물 중 Ipfencarbazone의 신규분석법 개발 및 검증

장진(Jin Jang),김희정(Heejung Kim),이은향(Eun-Hyang Lee),고아영(Ah-Young Ko),주윤지(Yunji Ju),김수연(Sooyeon Kim),장문익(Moon-Ik Chang),이규식(Gyu-Seek Rhee) 한국농약과학회 2015 농약과학회지 Vol.19 No.3

Ipfencarbazone is a herbicide of the tetrazolinone class, and is believed to be an inhibitor of very long chain fatty acids (VLCFAs), which control cell division in weeds. The objective of this study was to develop and validate an official analytical method for ipfencarbazone determination in agricultural products. The ipfencarbazone residues in agricultural products were extracted with acetone, partitioned with n-hexane, and then purified through silica SPE cartridge. Finally, the analyte was quantified by gas chromatographelectron capture detector (GC-ECD) and confirmed with gas chromatograph/mass spectrometer(GC/MS). The linear range of ipfencarbazone was 0.01 to 1.0 mg/L with the coefficient of determination (r<SUP>2</SUP>) of 0.9999. The limit of detection (LOD) and quantification (LOQ) was 0.003 and 0.01 mg/kg, respectively. In addition, average recoveries of ipfencarbazone ranged from 80.6% to 112.3% at the different concentration levels LOQ, 10LOQ and 50LOQ, while the relative standard deviation was 2.2-8.6%. All values were consistent with the criteria ranges requested in the CODEX guidelines. Furthermore, and inter-laboratory study was conducted to validate the method. This proposed method for determination of ipfencarbazone residues in agricultural products can be used as an official analytical method.

필기의 구조적 표현에 의한 온라인 자동 서명 검증 기법

김성훈(Kim Seong Hoon),장문익(Jang Moon IK),김재희(Kim Jai Hie) 한국정보처리학회 1998 정보처리학회논문지 Vol.5 No.11

For on-line signature verification, the local shape of a signature is an important information. The current approached, in which signatures are represented into a function of time or a feature vector without regarding of local shape, have not used the various features of local shapes, for example, local variation of a signer, local complexity of signature or local difficulty of forger, and etc. In this paper, we propose a new technique for on-line signature verification based on a structural signature representation so as to analyze local shape and to make a selection of important local parts in matching process. That is, based on a structural representation of signature, a technique of local weighting and personalized decision threshold is newly introduced and its experimental results under different conditions are compared.

농식품 환경 분야(PF) : HPLC-UVD를 이용한 대두 중 이마자피르의 분석법 개발

김희정 ( Heejung Kim ),장진 ( Jin Jang ),이은향 ( Eun Hyang Lee ),고아영 ( Ah Young Ko ),이지영 ( Ji Young Lee ),이상목 ( Sang Mok Lee ),조윤제 ( Yun Je Cho ),장문익 ( Moon Ik Chang ),정지윤 ( Ji Yun Jung ),이은주 ( Eun Ju Lee ) 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

Imazapyr [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin2-yl)nicotinic acid] is a non-selective herbicide which controls plant growth by inhibiting the production of branched-chain amino acids. Recently, it was registered in USA for the uses of soybean and its seed with MRLs 4.5 mg/kg and 4.0 mg/kg, respectively. To determine the maximum residue limit (MRL) for the food commodities in Korea, a new analytical method of imazapyr on soybean was developed and validated. Soybean samples were extracted with 60% methanol and partitioned with dichloromethane, adjusting pH to 2.5 by hydrochloric acid. Finally, they were analyzed by high performance liquid chromatography coupled to UV detector(HPLC-UVD). The linearity was good with a determination coefficient ( r2>0.99). Recovery studies were carried out at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. Recoveries were ranged between 70.4% and 80.1%, with relative standard deviations less than 5.4%. A consistent recovery was determined according to the CODEX guidelines(CAC/GL40). The developed method was useful for monitoring imazapyr residues in soybean. It can also be used for the analysis of imazapyr in other fruit and vegetable matrices.

행렬기반의 정합 알고리듬에 의한 음악 기호의 인식

허경용(Heo Gyeong Yong),장경식(Jang Kyung Sik),장문익(Jang Moon IK),김재희(Kim Jai Hie) 한국정보처리학회 1998 정보처리학회논문지 Vol.5 No.8

In pattern recognition and image analysis applications, a graph is a useful tool for complex object representation and recognition. However it takes much time to pair proper nodes between the prototype graph and an input data graph. Futhermore it is difficult to decide whether the two graphs in a class are the same because real images are degraded in general by noise and other distortions. In this paper we propose a matching algorithm using a matrix. The matrix is suitable for simple and easily understood representation and enables the ordering and matching process to be convenient due to its predefined matrix manipulation. The nodes which constitute a graph are ordered in the matrix by their geometrical positions and this makes it possible to save much comparison time for finding proper node pairs. For the classification, we defined a distance measure that reflects the symbol's structural aspect that is the sum of the node distance and the relation distance; the former is from the parameters describing the node shapes, the latter from the relations with other node in the matrix. We also introduced a subdivision operation to compensate node merging which is mainly due to the preprocessing error. The proposed method is applied to the recognition of musical symbols and the result is given. The result shows that almost all, except heavily degraded symbols are recognized, and the recognition rate is approximately 95 percent.

GC-ECD를 이용한 농산물 중 제초제 aclonifen의 공정분석법 확립

고아영 ( Ah Young Ko ),김희정 ( Hee Jung Kim ),장진 ( Jin Jang ),이은향 ( Eun Hyang Lee ),주윤지 ( Yoon Ji Joo ),권찬혁 ( Chan Hyeok Kwon ),손영욱 ( Young Wook Son ),장문익 ( Moon Ik Chang ),이규식 ( Gyu Seek Rhee ) 한국환경농학회 2014 한국환경농학회지 Vol.33 No.4

BACKGROUND: Aclonifen is used as a systemic and selective herbicide to control a wide spectrum broad-leaf weeds by inhibition carotenoid biosynthesis, and then its MRLs(Maximum Residue Limits) will be determined in onion and garlic. In this study, a new official method was developed for aclonifen determination in agricultural products to routinely inspect the violation of MRL as well as to evaluate the terminal residue level. METHODS AND RESULTS: Aclonifen was extracted from crop samples with acetone and the extract was partitioned with dichloromethane and then purified by silica solid phase extraction(SPE) cartridge. The purified samples were detected GC using an ECD detector. Limits of detection(LOD) was 0.001 mg/kg and quantification(LOQ) was 0.005 mg/kg, respectively. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10×LOQ, 50×LOQ, n=5). Therecoveries were ranged from 74.3 to 95.0% with relative standard deviations(RSDs) of less than 8%. All values were consistent with the criteria ranges requested in the Codex guidelines(CAC/GL 40). CONCLUSION: The proposed analytical method was accurate, effective and sensitive for aclonifen determination and it will be used to as an official method in Korea.

GC-MS를 이용한 바지락 중 prometryn 잔류분석법 확립

채영식(Young-Sik Chae),조윤제(Yoon-Jae Cho),장경주(Kyung-Joo Jang),김재영(Jae-Young Kim),이상목(Sang-Mok Lee),장문익(Moon-Ik Chang) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.5

Prometryn은 트리아진계 제초제로 일년생 쌍자엽 식물체와 같은 일년생 잡초 제거에 탁월한 효과가 있으나 일부 토양에 약효가 여러 달 지속될 경우 수중계에 스며들어 축적과 이동, 생물학적 농축(biomagnification)등의 심각한 환경문제를 비롯한 수질오염, 야생동물 및 국민건강에 심각한 문제를 일으킬 수 있는 잔류물질이다. 최근 국내에서 중국산 바지락 및 그 가공품에서 prometryn의 검출이 보고된 바 있어 이에 대한 지속적인 모니터링이 필요하기 때문에 바지락 중의 prometryn 분석법 개발이 필요한 실정이다. 본 연구에서는 수산물 중 바지락을 시료로 사용하였다. 시료를 아세토니트릴로 추출하고 농축한 다음 20% 아세톤 함유 헥산을 첨가하여 용해하였다. 이 용액을 florisil 카트리지로 정제한 후 농축하여 GC-MS로 분석하였다. 기기분석은 SIM 모드로 m/z 241 이온에 대하여 정량하였고, LOQ는 0.04 ㎎/㎏으로 계산되었으며, LOQ, 2×LOQ 농도에서의 회수율 및 분석오차가 각각 84.0-98.0%, 3.1-7.1%로 분석되어 Codex 가이드라인 규정에 만족하였다. We developed a simple, sensitive, and specific analytical method for prometryn using gas chromatography-mass spectrometry (GC-MS). Prometryn is a selective herbicide used for the control of annual grasses and broadleaf weeds in cotton and celery crops. On the basis of high specificity, sensitivity, and reproducibility, combined with simple analytical operation, we propose that our newly developed method is suitable for use as a Ministry of Food and Drug Safety (MFDS, Korea) official method in the routine analysis of individual pesticide residues. Further, the method is applicable in clams. The separation condition for GC-MS was optimized by using a DB-5MS capillary column (30 m×0.25 ㎜, 0.25 ㎛) with helium as the carrier gas, at a flow rate of 0.9 mL/min. We achieved high linearity over the concentration range 0.02-0.5 ㎎/L (correlation coefficient, r²>0.998). Our method is specific and sensitive, and has a quantitation limit of 0.04 ㎎/㎏. The average recovery in clams ranged from 84.0% to 98.0%. The reproducibility of measurements expressed as the coefficient of variation (CV%) ranged from 3.0% to 7.1%. Our analytical procedure showed high accuracy and acceptable sensitivity regarding the analytical requirements for prometryn in fishery products. Finally, we successfully applied our method to the determination of residue levels in fishery products, and showed that none of the analyzed samples contained detectable amounts of residues.

LC-MS/MS를 이용한 농산물 중 Cyclaniliprole과 대사산물의 동시시험법 개발

도정아 ( Jung-ah Do ),고아영 ( Ah-young Ko ),장진 ( Jin Jang ),주윤지 ( Yunji Ju ),임승희 ( Seung-hee Lim ),박신민 ( Shin Min Park ),장문익 ( Moon-ik Chang ),이규식 ( Gyu-seek Rhee ) 한국환경농학회 2016 한국환경농학회 학술대회집 Vol.2016 No.-

Cyclaniliprole은 2004년 일본 Ishihara Sangyo Kaisha(ISK) Ltd.에서 개발한 diamide계 살충제로 나비목, 총채벌레류, 굴파리류에 대해 높은 살충효과를 갖는 약제이다. 작용기작은 경구 및 경피를 통해 해충의 체내에 흡수되어 신속히 먹이 활동을 정지시키고, 근육세포에 존재하는 리아노딘 수용체를 활성화시켜 근소포체의 Ca2+ 이온을 이상 생산하며, 근육의 경련이나 위축을 일으켜 살충 활성을 나타내는 것으로 알려져 있다. Cyclaniliprole은 생물 및 작물에 대한 안전성을 확인하여 유럽, 미국, 아시아 등에 등록신청이 진행 중이며 국내에서도 2016년 고추, 배추, 파에 대해 등록 요청된 신규 농약이다. Cyclaniliprole은 식물 체내에서 2종의 대사산물(NK-1375, YT-1284)을 형성하는데 그 중 NK-1375는 총잔류방사능(TRR)이 10% 이상으로 검출되었고, 작물잔류성시험에서도 잔류성이 확인되어 모화합물과 함께 관리해야 한다. 따라서 본 연구에서는 cyclaniliprole 및 NK-1375의 동시 동시분석을 위한 공정시험법을 개발하고자 하였다. 또한 범용적 잔류농약 검사가 가능하도록 대표농산물 5종(감귤, 고추, 감자, 현미, 대두)을 이용하여 cyclaniliprole 및 NK-1375를 acetonitrile로 추출하였고, 이온화를 억압하여 유기 용매에 대한 분배효율을 높이기 위해 1 N HCl을 이용하여 pH를 3으로 조절한 뒤 dichloromethane으로 액-액 분배하였으며 유지시료는 n-hexane/acetonitrile 분배법을 추가하여 유지성분을 제거한 뒤 분석하였다. 분석기기는 모화합물의 열분해성과 대사산물의 간섭 영향을 고려하여 선택성이 높고 분석 감도가 우수한 LC-MS/MS를 이용하여 잔류물의 정확성 및 신뢰성을 동시에 확보하였다. 시험법의 검량선 상관계수(r2)는 0.99 이상으로 우수한 직선성을 나타냈고, 정량한계(LOQ)는 0.005 mg/kg으로 미량 정량이 가능하였다. 대표농산물에 LOQ, LOQ 10배, LOQ 50배 수준(0.005, 0.05, 0.25 mg/kg, n=5)으로 회수율 실험을 수행한 결과, 평균 회수율은 cyclaniliprole 81.2-111.5%, NK-1375 76.2-109.2%로 확인되었고, 상대표준편차는 9.4% 미만으로 조사되었다. 개발된 시험법은 국제식품규격위원회(CODEX)의 농약 시험법 가이드라인(CAC/GL 40, 2003)에 부합한 것으로 확인되어 국내 유통되는 농산물 중 cyclaniliprole의 잔류물 안전관리를 위한 공정시험법으로 활용할 수 있을 것으로 판단된다.

농산물 중 Thidiazuron의 잔류량 분석법 개선

도정아 ( Jung Ah Do ),이미영 ( Mi Young Lee ),박혜진 ( Hye Jin Park ),장효진 ( Hyo Jin Jang ),권지은 ( Jieun Kwon ),이소영 ( Soyoung Lee ),오재호 ( Jae Ho Oh ),장문익 ( Moon Ik Chang ),강일현 ( Il Hyun Kang ),이상목 ( Mok Sang Lee 한국환경농학회 2012 한국환경농학회 학술대회집 Vol.2012 No.-