• Applied Biological Chemistry
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• 제41권8호
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• pp.595-599
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• 1998

An analytical method was developed to determine tricyclazole residues in rice grain, straw, and soil using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. Tricyclazole was extracted with methanol from moist rice grain, straw, and soil samples. n-Hexane washing was employed to remove nonpolar co-extractives during liquid-liquid partition. Tricyclazole was then extracted with dichloromethane from alkaline aqueous phase, while acidic interferences remained in the phase. Dichloromethane extract was further purified by silica gel column chromatography prior to HPLC determination. Reverse-phase HPLC using an octadecylsilyl column was successfully applied to separate and quantitate the tricyclazole residue in sample extracts monitored at ${\lambda}_{max}$ 225nm. Recoveries from fortified samples averaged $95.5{\pm}3.0%\;(n=6),\;87.5{\pm}20.%\;(n=6),\;and\;84.3{\pm}2.8%$ (n=12) for rice grain, straw, and soil, respectively. Detection limit of the method was 0.02 mg/kg for rice grain and soil samples while 0.05 mg/kg for rice straw samples. The proposed method was reproducible and sensitive enough to evaluate the safety of tricyclazole residues in rice grain, straw, and soil.

• 한국환경농학회지
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• 제30권4호
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• pp.432-439
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• 2011

BACKGROUND: An official analytical method was developed to determine etofenprox residues in agricultural commodities using high-performance liquid chromatography (HPLC). METHODS AND RESULTS: The etofenprox residue was extracted with acetone from representative samples of five raw products which comprised rice grain, apple, mandarin, cabbage, and soybean. The extract was then serially purified by liquid-liquid partition and Florisil column chromatography. For rice and soybean samples, acetonitrile/n-hexane partition was additionally coupled to remove nonpolar lipids. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate etofenprox from co-extractives. Intact etofenprox was sensitively detected by ultraviolet absorption at 225 nm. Recovery experiment at the quantitation limit validated that the proposed method could apparently determine the etofenprox residue at 0.02 mg/kg. Mean recoveries from five crop samples fortified at three levels in triplicate were in the range of 93.6~106.4%. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types. A selected-ion monitoring LC/mass spectrometry with positive atmospheric-pressure chemical ionization was also provided to confirm the suspected residue. CONCLUSION(s): The proposed method is simple, rapid and sensitive enough to be employed in routine inspection or monitoring of agricultural products for the etofenprox residue.

• 한국식품영양과학회지
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• 제25권4호
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• pp.632-636
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• 1996

비지는 59.0%의 식이섬유를 함유하였고 막걸리박은 26.0%의 식이섬유를 gakdb하였다. 밀가루에 비지나 막걸리박을 10% 혼합하여 빵을 만들어 제빵 특성을 100% 밀가루빵과 비교하였다. 비지나 막걸리박을 10% 혼합하였을 때 반죽의 수분 흡수율과 빵의 무게는 증가하였으나 빵의 부피는 40% 정도 r마소하였다. 관능검사 결과 비지빵과 막걸리빵의 색깔, 모양, 속결의 질감 등은 100% 밀가루빵에 비하여 품질이 떨어졌다. 비지빵의 단백질 함량은 밀가루빵의 13.5%에서 15.4%로 증가하였고, 막걸리빵의 경우 16.4%로 증가하였다. 빵의 식이섬유 함량은 비지빵의 겨우 밀가루빵의 3배, 막걸리빵의 경우 2배로 증가하였다.

• 한국환경농학회지
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• 제18권4호
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• pp.384-387
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• 1999

논 토양과 현미 중 살충제 imidacloprid의 잔류성을 조사한 결과는 다음과 같다. 실내 조건의 토양 중 imidacloprid의 분해속도는 1차 반응식에 따랐으며 토양온도 및 토양 종류에 크게 영향을 받았다. $18-23^{\circ}C$의 토양중 imidacloprid의 반감기는 증식토에서 66.7-96.3일, 식양토에서 56.8-117.5일이었다. Arrhenius activation energy는 증식토에서 25.5KJ/mol, 식양토에서 50.3KJ/mol이었다. 포장조건하의 토양 중 imidacloprid의 분해는 처리 초기에는 매우 빨랐으나 점점 분해속도가 느려 1차반감기는 약 10일 정도이었으나 2차, 3차 반감기는 점점 길어져 처리량의 90%까지 분해되는데는 약 120일이 소요되었다. 현미 중 imidacloprid의 잔류량은 검출한계 0.01ppm이하이었다.

• 한국식품영양학회지
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• 제10권1호
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• pp.92-96
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• 1997

시판 식혜에는 설탕과 프룩토오스, 글루코오스, 말토오스 및 여러 사이즈의 말토올리고당, 한계덱스트린이 함유되어 있다. 그 중 한계덱스트린은 0.09%, 밥알은 0.2%를 나타냈다. 1H-NMR 분석 결과, 한계덱스트린은 $\alpha$-1,4-결합 및 $\alpha$-1,6-결합이 15:1의 비율을 나타냈다. Pullulanase 처리로, 말토오스에서 글루코오스 10잔기 이상의 말토올리고당까지 다양한 분포를 나타냈다. 한계덱스트린은 여러 아미라아제 처리 결과, 전통식혜보다 가수분해율이 훨씬 높았다. $\alpha$-글루코시다아제와 타액 $\alpha$-아밀라아제를 공동 작용시킨 경우는 62% 가수분해되었다. 그러나, 밥알의 가수분해율이 매우 낮았다. 그래서 전통 식혜에 비해 한계덱스트린의 비피두스 인자로서의 효과는 적고, 밥알의 식이섬유 작용은 커졌다.

• 한국환경농학회지
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• 제23권4호
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• pp.251-257
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• 2004

Analytical methods were developed to determine cyclosulfamuron residues in soil, water, rice grain and straw using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. In these methods, cyclosulfamuron was extracted with aqueous $Na_2HPO_4$/acetone and acetone/methanol mixture from soil and rice samples respectively. Liquid-liquid partition coupled with ion-associated technique, Florisil column chromatography, and solid-phase extraction (SPE) were used to separate cyclosulfamuron from interfering co-extractives prior to HPLC analysis. For water sample, the residue was enriched in $C_{18}$-SPE cartridge, cleaned up in situ, and directly subjected to HPLC. Reverse-phase HPLC under ion-suppression was successfully applied to determine cyclo-sulfamuron in sample extracts with the detection at its ${\lambda}_{max}$ (254 nm). Recoveries from fortified samples averaged $87.8{\pm}7.1%$ (n=12), $97.3{\pm}7.2%$ (n=12), $90.8{\pm}6.6%$ (n=6), and $78.5{\pm}6.7%$ (n=6) for soil, water, rice grain and straw, respectively. Detection limits of the methods were 0.004 mg/kg, 0.001 mg/L, 0.01 mg/kg and 0.02 mg/kg for soil, water, rice grain and straw samples, respectively.

• Applied Biological Chemistry
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• 제37권6호
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• pp.487-491
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• 1994

나락을 열풍팽화기로 팽화시켜 현미와 왕겨의 결정화도, 당화율, 농약잔류량의 변화를 비교하였다. 나락의 팽화처리로 쌀전분의 결정화도가 감소하였으나 왕겨의 결정화도는 큰 변화가 없었다. 찰벼의 팽화처리는 자숙처리에 비하여 엿기름 amylase에 의한 당화율이 높았으며 왕겨의 cellulase에 의한 가수분해율은 팽화처리시 $14{\sim}30%$ 상승되었다. 나락의 팽화처리로 왕겨와 현미 중의 농약(diazinon)의 잔류량 감소는 메벼에서 현저하였고, 팽화전에 비하여 현미와 왕겨에서 각각 42.7%, 47.6% 잔류되었다.

• 한국작물학회지
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• 제42권5호
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• pp.564-570
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• 1997

두과식물인 자운영을 논에 재배하여 유기물 및 질소공급원으로 활용함과 동시에 피복식물로서 잡초방제등 부수적인 효과를 얻기 위하여 자운영 방치, 예취 제거 등 그 이용방법을 달리하여 1995년과 1996년 2년동안 경상남도농촌진흥원 포장에서 시험을 수행한 결과를 요약하면 다음과 같다. 1. 시험후 토양화학성은 자운영 이용방법의 차이에 따라 일정한 경향이 없었으며, 토양심도별로 비교하여 보면 pH와 Ca, Mg는 심토(10~20cm)에서, 유기물과 P$_2$ $O_{5}$, K는 표토(0~10cm)에서 그 함량이 높았다. 2. 토양의 산화환원전위는 자운영 예취구의 담수초기 때 심한 환원상태를 보이다가 시일이 경과함에 따라 그 정도가 완화되는 경향이었으며, 자운영을 방치하였을 경우 다른 처리에 비하여 환원 정도가 더 심하였고, 최고분얼기경에 다시 높아지는 경향을 보였다. 3. 잡초방제후 최고분얼기경 잡초발생은 자운영 방치답에서 가장 많았고, 다음이 예취후 제거답이었으며, 비선택성 제초제를 살포하여 자운영을 고사시킨 답에서는 그 발생량이 가장 적었다. 4. 벼 입모율은 자운영 재배답에서 가장 낮았고, 출수기 때의 생육은 각 처리간 비슷하였으며, 수량은 자운영 경운답에서 가장 높고, 다음이 관행 경운답이었으며, 자운영을 방치 혹은 예취후 제거하거나 비선택성 제초제를 살포하여 고사시킨 답에서 다소 감수되는 경향이었다.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2671-2674
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• 2013

To elucidate the role of the evolutionarily conserved Tyr8 residue in rice Phi-class GSTF3, this amino acid was replaced with alanine and phenylalanine by site-directed mutagenesis, respectively. The replacement of Tyr8 with Ala significantly affected the catalytic activity and the kinetic parameters, whereas the substitutions of Tyr8 with Phe had almost no effect. The Y8A mutant resulted in approximately 90-100% decrease of the specific activity. Moreover, the Y8A mutant resulted approximately in 2-fold increase of $K_m$, approximately 60-80% decrease of $k_{cat}$, and approximately 6.5-fold decrease in $k_{cat}/K_m$. From the pH/log $k_{cat}/K_m$ plot, $pK_a$ values of the GSH in the wild-type enzyme-GSH complex, Y8A-GSH complex and Y8F-GSH complex were estimated to be approximately 6.8, 8.5 and 6.9, respectively. From these results, we suggest that the evolutionarily conserved Tyr8 residue in OsGSTF3 seems to influence the structural stability of the active site of OsGSTF3 rather than directly its catalytic activity.

• 한국토양비료학회지
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• 제47권6호
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• pp.553-557
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• 2014

The steady increase in livestock industry has greatly required the stable production of food and forage crops. As an alternative, rice-forage cropping system has been attempted in several southern areas. The present study was performed to understand whether an application of cattle-manure compost affects soil chemical properties and crop productivity in rice-forage cropping system, rice ${\rightarrow}$ summer oat ${\rightarrow}$ rye, in Jangheong county, south Jeolla province from 2013 to 2014. Treatments was composed of control (no compost), CM1 (compost application before rice transplanting), and CM2 (two-times compost application, before rice transplanting and after rice harvest), and inorganic fertilizers (N, P, and K) were equally dressed in all plots. Yields of rice were not significantly different between treatments, however, oat production was 1.25-fold higher in CM1 and CM2. Nutrient uptake amounts of rye were higher in CM2 than CM1 and control. Total nitrogen in soil was maintained stable level during crop cultivation. And soil organic matter contents in all treatments were increased by crop residue. Available P_2O_5$ and exchangeable K were increased by cattle manure application. Therefore, it suggested that the amount of nutrient by forage crop residue should be considered in rice-forage multiple cultivation.