• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.57-65
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• 2018

BACKGROUND: An analytical method was developed using HPLC-UVD/MS to precisely determine the residue of flusulfamide, a benzenesulfonamide fungicide used to inhibit spore germination. METHODS AND RESULTS: Flusulfamide residue was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice, and soybean. The extract was diluted with large volume of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. On an octadecylsilyl column in HPLC, flusulfamide was successfully separated from co-extractives of sample, and sensitively quantitated by ultraviolet absorption at 280 nm with no interference. Accuracy and precision of the proposed method was validated by the recovery experiment on every crop sample fortified with flusulfamide at 3 concentration levels per crop in each triplication. CONCLUSION: Mean recoveries ranged from 82.3 to 98.2% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of flusulfamide was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring technique was also provided to clearly identify the suspected residue.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.146-151
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• 2012

BACKGROUND: This study was conducted to develop analytical method for picoxystrobin in agricultural commodities using GC/ECD and GC/MS. METHODS AND RESULTS: Each steps of analytical method were optimized for determining picoxystrobin residues in various agricultural commodities. The developed methods include acetone extraction, n-hexane/saline water partition and florisil column chromatography for analysis of all samples (apple, potato, green pepper, hulled rice and soybean), and in addition to these steps, solid phase extraction (SPE) was used for analysis of green pepper and n-hexane/acetonitrile partition was used for analysis of hulled rice and soybean. The instrumental conditions were tested for quantitation in GC/ECD and for confirmation in GC/MS. Recovery was in the range of 86~109% with RSD ${\leq}$10.2% and the quantitation limits (LOQ) of method were 0.025 mg/kg in all agricultural commodities. CONCLUSION: The result showed that the developed method can be used to determine picoxystrobin residue in agricultural commodities.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.339-346
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• 2018

Cyanazine is a member of the triazine family of herbicides. Cyanazine is used as a pre- and post-emergence herbicide for the control of annual grasses and broadleaf weeds. This experiment was conducted to establish a determination method for cyanazine, as domestic unregistered pesticide, residue in major agricultural commodities using HPLC-DAD/MS. Cyanazine was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and partitioned to dichloromethane for remove polar extractive in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized florisil column chromatography. On a $C_{18}$ column in HPLC, cyanazine was successfully separated from co-extractives of sample, and sensitively quantitated by diode array detection at 220 nm. Accuracy and precision of the proposed method was validated by the recovery experiment on every major agricultural commodity samples fortified with cyanazine at 3 concentration levels per agricultural commodity in each triplication. Mean recoveries were ranged from 83.6 to 93.3% in five major representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation(LOQ) of cyanazine was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring(SIM) technique was also provided to clearly identify the suspected residue.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.253-257
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• 1998

Behaviour of a fungicide $^{14}C-propiconazole$ was investigated in a field lysimeter of sandy loam soil. At 15 days after rice-seedling transplanting, $^{14}C-propiconazole$ was treated on the soil surface at the rate of 0.12 kg/10a. The cummulative $^{14}C-radioactivity$ in the leachate from the lysimeter soil was 4.4% of the applied $^{14}C$ for 16 weeks. Most radioactivity detected in leachate was in the form of parent compound. At the end of lysimeter experiment. $^{14}C$ radioactivity in lysimeter soil was 76.5% of the applied $^{14}C$ and more than 97% of $^{14}C$ in soil remained in the top 20 cm. The percent of $^{14}CO_2$ evolved from lysimeter soil was 7.8% of the applied $^{14}C$. The radioactivity remained in the rice straw after harvest was 7.2% of the applied $^{14}C$, while less than 0.1% of the applied $^{14}C$ was detected in flag leaf, ear, chaff and hulled rice, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.184-188
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• 1983

This experiments were carried out to know the effect of ripened grain under low temperature ($20^{\circ}C/13^{\circ}C$) and out door condition when 2 chemicals including. Dachigaren were applied at 7-8 days before heading and heading stage. Low temperature plot is more effective than out door temperature plot to chemicals. Secondary tillers is more effective than primary tillers to chemicals. SZ8028+ABA is the most effective chemical than Dachigaren and SZ8028. SZ8028+ABA is the most effective chemical regardless of low or high temperature to ripeness. Iri 327 is higher than Jinheung.. The plot of SZ8028+ABA or Dachigaren applied is higher than SZ8028 or control at 0-20% of sterile. Percentage of hulled rice above 2.0mm was increased 87.6% of Dachigaren, 88.7% of SZ8028 90.2% of SZ8028+ABA compared with 83.4% of control.

• Korean Journal of Food Science and Technology
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• v.2 no.1
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• pp.104-112
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• 1970

Korean Paldal variety rice, harvested November and hulled into polished and unpolished forms in April, 1969, packed in the straw bags and the kraft paper bags. Being irradiated with 10, 30 and 50 krad ${\gamma}-ray$, the samples were stored at room temperature for testing infestation, uric acid content, fat acidity, riboflavin content and panel test. The results are as follows. 1. The kraft bag lot with polished rice or unpolished rice manifested the apparent disinfestation with $30{\sim}50$ krad irradiation. On the other hand, in the straw bag lot the irradiation effects on disinfestation were weakened through summer on account of the second contamination. 2. The changes of uric acid content in rice were proportional to the state of infestation. 3. Fat acidity, which has a close relation with the rancidity of fat in rice, increased during storage and showed some increasing tendency in the irradiated lot with $30{\sim}50$ krad. 4. In comparison with the control lot, riboflavin content was not affected by 50 krad irradiation. 5. With 10, 30 and 50 krad dose, the irradiated lot should have no significant difference in taste, odour, color and viscosity for the panel test.

• Research in Plant Disease
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• v.11 no.2
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• pp.93-97
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• 2005

In order to detect casual agents associated with ear blight of rice, seed samples of 'Ilmi-byeo' and 'Daesan-byeo', susceptible cultivars were collected from 28 regions on a nationwide scale. Finally 23 fungi including Bipolaris oryzae($10.3\%$), Alternaria alternata ($10.2\%$), Cladosporium sp. ($7.5\%$), Nigrospora oryzae($5.2\%$) and Phoma sorghina ($6.3\%$) from seeds of 'Ilmi-byeo', and 13 fungi including N. oryzae ($15.1\%$), A. alternata ($9.6\%$) and Curvularia lunata ($2.2\%$) from seeds of 'Daesan-byeo' were detected. In case of discolored seeds caused by rice ear blight, B. oryzae($15.5\%$), A. alternata ($5.5\%$), Fusarium graminearum ($8.0\%$), N. oryzae($5.2\%$) and P. sorghina ($4.5\%$) were detected even from the hulled rice of Ilmi-byeo.

• Research in Plant Disease
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• v.14 no.3
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• pp.153-158
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• 2008

This study was conducted to develop a easy seedling method to test large amounts of barley and wheat cultivars for resistance of powdery mildew. In addition, we also examined the resistance of genetic resources that have been used in barley and wheat breeding programs in Korea. This seedling test used paper bag with seeds can be completed within three weeks. to-day seedlings were available to inoculation and 8 days was needed for result reading. This method can test at least 180 collections at one time. we can identify the two resistant types by leave symptoms showed non infection and necrotic spots. Among the 79 Korean barley cultivars, only two cultivar, 'Sangrokbori' and 'Dajinbori' were resistant and 'Jejubori' showed moderate resistant. There was no resistant in hulless barley and wheat cultivars. It was same results in comparison of earlier resistant reports in field test. We confirm that this method could using in test of powdery mildew resistance in barley and wheat. Among the 1,401 genetic resources using in Korean breeding program, malting barley has more resistant collections comparing to 796 hulled and hulless barley and 273 wheat germplasms.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.269-276
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• 2001

Several experiments including persistence, distribution, leaching, and terminal residue trials were carried out to investigate the behavior of cyclosulfamuron in rice paddies. Cyclosulfamuron was gradually dissipated in two different soils showing the first-order kinetics. Half-lives of the herbicide were calculated to be $17{\sim}30$ and $14{\sim}16$ days under field and laboratory conditions, respectively. In the paddy soil/water system, the residue tended to reside more in the soil phase as time elapsed. Cyclosulfamuron was less persistent in paddy water than in soil with half-lives of 10 and 19 days, respectively. No cyclosulfamuron was leached below 20 cm-deep soil during water percolation with 50 cm hydraulic head, while some downward mobility was observed within the soil column. When EC and SC formulations of cyclosulfamuron were applied to the paddy field at 120 or 150-day pre-harvest intervals, its terminal residues in hulled rice were all less than 0.01 mg/kg, irrespective of formulation type and application timing. In rice straw, however, some residues were found at $<0.02{\sim}0.05$ mg/kg as SC formulation was applied. Rapid dissipation, restricted mobility, and low terminal residues of cyclosulfamuron in rice paddies suggest that no significant residues would be transported or carried over to the non-target environment.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.55-60
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• 2008

Colored rices are a hulled grains having red or purple pigments in bran. Especially black rice (Heugjinjubyeo) is considered to be a healthy food in Asia. Black rice is of great interesting because of the possible biological activity with their anthocyanins. Anthocyanins are water-soluble plant pigments and representatives of flavonoids. The anthocyanins in black rice include cyanidin 3-O-glucoside, peonidin 3-O-glucoside, malvidin 3-O-glucoside, pelagonidin 3-O-glucoside and delphinidin 3-O-glucoside. In this study, anthocyanins in a black rice were analyzed quantitatively and qualitatively with HPLC and UV-Vis spectrophotometer. The anthocyanins contained approximately 95% of cyanidin-3-O-glucoside and 5% of peonidin-3-O-glucoside. Antioxidant activities of the anthocyanin extract were investigated by using various in vitro methods. The 100g/ml concentration of the anthocyanin extracted exhibited 88.83% inhibition on the peroxidation of linoleic acid, 55.20% DPPH free radical scavenging activity, 54.96% superoxide anion radical scavenging activity, and 72.67% hydrogen peroxide scavenging activity. And it also showed high ferrous ion reducing capability. These results suggest that the anthocyanin extracted from black rice may be utilized as a possible antioxdiant agent against ROS.