고성능 액체크로마토그래피를 이용한 당귀 중 Azocyclotin 및 Cyhexatin 잔류분석법

조범석 ( Beom Seok Cho ),이영득 ( Young Deuk Lee ),성락선 ( Rack Seon Seong ),이재준 ( Jae Jun Lee ) 한국환경농학회 2013 한국환경농학회 학술대회집 Vol.2013 No.-

A High-performance liquid chromatographic (HPLC) method to determine residues of azocyclotin and cyhexatin in dry root of Angelica gigas, a medicinal herb was developed for the official inspection. Azocyclotin and cyhexatin were extracted from the moistened sample with acetone/hydrobromic acid mixture. Following to dilution of the extract with saline, the analyte was partitioned into the hexane phase. During extraction and partition steps, azocyclotin was completely converted to cyhexatin. Ion-suppressed silica gel column chromatography was employed for further purification of the extract prior to HPLC determination. In reversed-phase HPLC using an octadecylsilyl column, cyhexatin could be eluted only when hydrochloric acid and sodium chloride was added to the mobile phase and quantitated by ultraviolet absorption at 214 nm. No interference was found in the sample extract and, as a result, quantitation limit of the proposed methods ranged 0.04∼0.05 mg/kg. Mean recoveries from samples fortified with azocyclotin and cyhexatin were in the range of 80.7∼82.0% and 81.2∼83.2%, respectively. Relative standard deviations of the analytical method were less than 10%. Even though the LC/mass spectrometry was failed due to poor ionization of cyhexatin, an alternative HPLC parameter could be applied for confirmation in situ as the dramatic change in retention behavior between co-extractives and the analyte was observed.

05 포스터 발표 : 환경 화학 분야(PC) ; PC-09 ; 과실 및 채소류 중 Pyrimidifen의 잔류분석법 개발

조범석 ( Beom Seok Cho ),이영득 ( Young Deuk Lee ) 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

A gas-liquid chromatographic (GLC) method was developed to determine residues of pyrimidifen, an acaricide/insecticide, for the official inspection of fruits and vegetables. The pyrimidifen residue was extracted with acetonitrile from samples and the extract was then serially purified by liquid-liquid partition and Florisil column chromatography. Isothermal GLC using ultrabore capillary column by direct injection mode was employed to ensure consistency and repeatability of instrumental quantitation even in high column temperature. Both electron-capture and nitrogen-phosphorus detectors were successfully applied for the determination of the pyrimidifen residue with no interference by sample co-extractives. Recovery experiment at the quantitation limit validated that the proposed method could apparently determine the pyrimidifen residue at 0.02 mg/kg. Mean recoveries from four fruit and vegetable samples fortified at three levels in triplicate were in the range of 93.1∼109.3%. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types. A selected-ion monitoring GC/mass spectrometry with electron impact was also provided to confirm the suspected residue. The proposed method is simple, rapid and sensitive enough to be adopted in routine inspection or monitoring of agricultural products for the pyrimidifen residue.

전부원가계산과 경영자의 재고관리 유인에 대한 시장평가

조범석(Cho, Beom Seok),김경민(Kim, Kyung Min) 한국국제회계학회 2014 국제회계연구 Vol.0 No.53

본 연구는 전부원가계산시스템 하에서 과대 생산을 통해 재고에 행사된 경영자 재량에 기회주의적 이익조절 유인이 지배적이라는 명제를 실증하는데 필요한 가설과 이와 일관된 실증 증거를 제시한다. 경영자가 이익조절 수단으로 정상 영업활동을 벗어나 과대 생산을 통해 재고에 행사하는 재량은 실질적인 경영 부담을 야기하여 기업가치 감소를 초래하며 외부주주의 이해와 상충된다. 본 연구에서 재고에 행사된 경영자 재량은 정상 영업활동을 통제한 비정상재고(abnormal inventory)로 대리되고 재고와 매출의 선형관계를 가정하여 제시한 비정상재고 모형(abnormal inventory model)을 통해 측정된다. 가설 검증은 최성규(1994)의 이익-주가반응 모형의 틀에 기초하여 비정상재고 투자의 기회비용과 더불어 규모, 산업 및 연도 효과를 통제한 비정상재고의 시장반응계수를 통해 검증한다. 본 연구결과를 요약하면, 비정상재고와 시장반응계수 간에 일관된 유의한 부(-)의 관계를 보이면서 시장이 비정상재고에 대해 부정적으로 인지하는 것으로 나타났다. 이는 재고에 행사된 경영자 재량에 기회주의적 이익조절 유인이 지배적임을 보여주는 실증 결과이다. 이상의 연구결과는 지난 20세기 중반 이래 전부원가시스템 하에서 경영자의 과도한 생산량 증가로 회계이익이 높이 계상되어 경영성과가 왜곡될 가능성에 대한 회계학자들의 오랜 염려를 실증적으로 지지한다. This paper investigates and tests a hypothesis concerning the proposition that manager’s opportunistic incentive is dominant in managerial discretion on inventory under full costing. Overproduction is a costly means of earnings management that incurs real operating activity burden and the decrease of firm value, which conflicts with the stockholders’ benefits. In this study, Abnormal inventory is a proxy for Managerial discretion on inventory, which is measured by an abnormal inventory model based on the linear relation of inventory and sales. Whether abnormal inventory increased from managerial discretion is opportunistic can be inferred by market assessment. The analysis for market assessment is based on the framework of the earning-price response model by Choi(1994) and controls variables of opportunity cost of abnormal inventory investment as well as the effect of size, industry and years. In the results, the market response coefficient on abnormal inventory is significantly negative, which is consistent with the hypothesis. The results imply that with the managerial discretion on inventory through overproduction, opportunistic incentive is dominant. This study provides empirical evidence about the controversial accounting issue of the defect of full costing from the middle of twentieth century until now.

AI를 이용한 모자이크 처리의 자동화, ‘B.A.M.O.S’

심한뫼(Han-Moi Shim),조범석(Beom-Seok Cho),염철준(Cheol-Jun Yeom),오준휘(Jun-Hwi Oh),우영학(Young-Hak Woo) 한국컴퓨터정보학회 2022 한국컴퓨터정보학회 학술발표논문집 Vol.30 No.1

06 식품의약품안전처 SESSION : 농산물 중 Thiocarbamate 및 Carboxamide계 농약의 공정 잔류분석법 개발

이영득 ( Young Deuk Lee ),조범석 ( Beom Seok Cho ) 한국환경농학회 2014 한국환경농학회 학술대회집 Vol.2014 No.-

Gas-liquid chromatographic (GLC) and high-performance liquid chromatographic (HPLC) methods to determine residues of thiocarbamate and carboxamide pesticides are developing for the official inspection of agricultural products. Sample preparation procedures including extraction, partition and Florisil column chromatographic purification were optimized for the simultaneous or individual GLC analysis of five thiocarbamate/carbamate fungicides/herbicide residues in crops. Total of three carboxamide fungicides including ethaboxam. isotianil andtiadinil were also subjected to development for official method of residue analysis. Reversed-phase HPLC using octadecylsilyl columns were employed to separate and determine the analytes using ultraviolet detection. Ethaboxam showed weakly basic nature unlikely to weak acid reported in the current literature. Optimization was undertaken for the sample preparation including extraction, partition and Florisil column chromatographic purification for carboxamide residues as well. Isotianil and tiadinil showing similar polarity could be determined at the same time by single sample preparation where as separate preparation was needed for analysis of ethaboxam with higher polarity. Limit of quantitation of the proposed methods could range 0.02~0.05 mg/kg as estimated by preliminary results. Recovery experiments are ongoing to validate the methods in representative agricultural commodities. Confirmatory or additional quantitative methods would be also conducted using mass spectrometric techniques.

식품의약품안전처 SESSION : 농산물 중 비극성 살응애제의 잔류분석법

이영득 ( Young Deuk Lee ),조범석 ( Beom Seok Cho ) 한국환경농학회 2013 한국환경농학회 학술대회집 Vol.2013 No.-

대표 농산물을 대상으로 bromopropylate, chlorfenapyr, etoxazole, pyrimidifen, spirodiclofen 등 비극성 살응애제 5종에 대한 공정 잔류분석법을 개발하고자 하였다. 통합적으로 분석용 시료를 조 제하되 각 성분들은 개별적으로 정밀 정량함으로써 분석의 효율성을 높임과 동시에 잔류허용기준 의 위반 여부를 명확히 판별할 수 있는 개별 분석법을 확립하였다. 적용 농산물 군의 대표 농산물 로서 현미, 사과, 감귤, 고추, 배추의 5종을 선정하였으며 각 함수 시료로부터 대상 성분들을 acetonitrile로 동시에 추출하였다. 추출물을 흡인 여과한 후 농축 과정 없이 다량의 식염수로 희석 한 후 직접 비극성 용매로 분배 추출하였으며 유지 함유 시료는 n-hexane-acetonitrile 분배법을 추 가하여 비극성 방해물질을 제거하였다. 분배 추출액은 Florisil column chromatography로 최종 정 제하여 기기분석에 공시하였다. Bromopropylate, chlorfenapyr, pyrimidifen 및 spirodiclofen은 GLC/ECD, etoxazole 및 pyrimidifen은 GLC/NPD와 HPLC/UVD를 적용하여 최적 기기분석 조건을 설정하였다. 확립된 시료 조제 및 기기분석법의 결과 무처리 농산물 시료 중 간섭물질은 관찰되지 않았다. 분석법 검증실험의 결과, 잔류분석기준인 정량한계 0.05 mg/kg 이하 및 허용기준의 1/2과 회수율 70∼120% 이내를 충분히 만족하였으며 분석오차는 대상 농약과 농산물 시료에 상관없이 10% 이내였다. 시료 중에서 검출된 잔류분에 대한 정성적 신뢰성을 확보하기 위하여 추가의 크로 마토그래피법과 질량분석기을 이용한 재확인법을 제시하였다.

HPLC 및 질량분석학적 재확인법을 이용한 농산물 중 Urea계 제초제 잔류분석법

이영득 ( Young Deuk Lee ),조범석 ( Beom Seok Cho ),도정아 ( Jung Ah Do ) 한국환경농학회 2012 한국환경농학회 학술대회집 Vol.2012 No.-

이수 순환 시스템의 장비 고장 예측 장치 및 방법

김길현(Kil Hyun Kim),김승광(Sung Kwang Kim),조범석(Beom Seok Cho) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.5