• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.977-983
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• 2002

This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.12
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• pp.1653-1661
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• 2007

The research aimed to establish the standard extraction procedure for examining brazilin, the major chromophoric substance of Sappanwood, using GC-MS with the ultimate goal of identifying the sappanwood dye in severely faded archaeological textiles. The amount of brazilin represented by the GC abundance was the largest when acetone was used as the extraction medium, followed by methanol. Shaking plate operated at room temperature was more effective than the waterbath shaker which was operated at $30^{\circ}C$. In both cases, the extraction method which incorporated one hour pre-soaking before the 12 hours of actual extraction resulted in a larger amount of brazilin detection than the extraction procedure without the one hour pre-soaking. In case of water extraction, pH 5 resulted in the most effective pH level for the extraction of brazilin, The best GC-MS parameter for detecting brazilin was to set the column temperature initially at $50^{\circ}C$. gradually increase to $210^{\circ}C$ at a $23^{\circ}C/min$ rate, finally increase to $305^{\circ}C$ at $30^{\circ}C/min$ rate, and hold for 14 minutes, and the MSD scan range at $75{\sim}400m/z$.

• Clean Technology
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• v.29 no.2
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• pp.109-117
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• 2023

The purpose of this study is to develop a method for separating antioxidants and sugars from grape skin extract. The extract was first mixed with a variety of organic solvents to investigate whether the separation was feasible. When employing acetone, ethanol, dimethylsulfoxide, or dimethylformamide, the organic solvent-extract combination formed a single phase. However, when benzene, ethyl acetate, or n-hexane was added to the extract, the mixture separated into an organic and an aqueous phase and the pigments remained in the aqueous phase. On the other hand, when polyethylene glycol-2,000 (PEG-2000) and sodium citrate were added to the extract, the mixture was separated into three layers, with the majority of the flavonoids migrating to the top layer and 53% of the extract's glucose migrating to the bottom layer. The top layer had significant antioxidant activity, whereas the bottom layer showed no antioxidant activity. The glucose recovery in the bottom layer increased as the molecular weight of PEG increased and the highest recovery (67%) was observed when PEG-8,000 was added. The highest flavonoid separation was observed with PEG-2,000, followed by PEG-8,000 and PEG-400. The flavonoid separation when PEG-2,000 was added resulted in a flavonoid recovery of 48% and 0.2% from the top and bottom layers, respectively. Examining the effect of the separated solution using the agar disc diffusion method on yeast cell growth confirmed that the addition of the extract, the top, and the bottom layer did not inhibit cell growth.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.56-64
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• 2002

2kg of the dried leaves of Thuja orientalis Linnaeus were ground, extracted with acetone-$H_2O$(7:3, v/v), concentrated, and fractionated with a series of hexane, $CH_2C1_2$ EtOAc and water on a separators funnel. Each fraction was freeze dried to give dark-brown powder and a EtOAc soluble portion. of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of isolated compounds. The leave of Thuja orientalis Linnaeus contained a large amount of flavononol derivatives such as quercetin-3-O-$\alpha$-L-rhamnopyranoside and myricetin-3-O-$\alpha$-L-rhamnopyranoside in addition to a small amount of flavan compounds such as (+)-catechin and (+)-gallocatechin. The antioxidative activities of each fractions and isolated compounds were done by DPPH radical scavenging test, and all of them were indicated strong antioxidative activities.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.59-66
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• 2004

The dried neeldes(1.5 kg) of Juniperus rigida were ground, extracted with acetone-H₂O(7:3, v/v), concentrated, and fractionated with a series of hexane, CH₂Cl₂, EtOAc and water on a separatory funnel. Each fraction was freeze dried to give dark-brown powder and EtOAc and water soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluent. Spectrometric analysis such as NMR and FAB or EI-MS including TLC were performed to characterize the structures of the isolated compounds. The needles of Juniperus rigida contained a large amount of (+)-catechin, quercetin-3-O-α-L-rhamnopyranoside and isoconiferin, in addition to a small amount of umbelliferone and quercetin-3-O-β-D-rutinoside. The antioxidative activities of each fraction and isolated compounds were tested by DPPH radical scavenging method, and EtOAc soluble fraction, (+)-catechin and quercetin-3-O-α-L-rhamnopyranoside were effective.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.141-147
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• 2014

Fenpyroximate is acaricide of pyrazole group. This acaricide have already been permitted for herb cultivation. This experiment was conducted to establish a determination method for fenpyroximate residue in herbal medicines using HPLC-PDA and HPLC-MS/MS. Fenpyroximate residue was extracted with acetone from samples of herbal which Liquorice Root (Glycyrrhiza uralensis) and Safflower Seed (Carthamus tinctorius Linne). The extract was diluted with saturated saline water and dichloromethane liquid-liquid partition (extraction) was followed to recover fenpyroximate from the aqueous phase. Amino propyl ($NH_2$) and florisil column chromatography was additionally employed for final clean up of the extract. The fenpyroximate was quantitated by HPLC-PDA and HPLC-MS/MS. The herbals were fortified with fenpyroximate at 2 or 3 levels per crop. Mean recovery ratio were ranged from 72.0 to 106.4%. The coefficients of variation were ranged from 0.2 to 4.4. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fenpyroximate in herbal medicines.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.193-202
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• 1991

Antimicrobial substances were screened by paper disk plate method in marine sponges, Halichondria okadai, Halichendria sp., H iaponica and Haliclona Pemollis, collected from the south coast of Korea. Antibacterial components were detected in two species, H okadai and Halichondria sp.. Three components such as benzoic acid, okadaic acid(OA) and dinophysistoxin-1(DTX1) were identified from these sponges as the antimicrobial compounds by MS and NMR spectral data. OA$(550{\~}600{\mu}g/kg)$ and $(400{\~}490{\mu}g/kg)$ were determined from the wet H okadai and Halichondria sp., respectively, by using fluorometric HPLC analysis with 9-anthryldiazomethane(ADAM) as fluorescent labelling reagent.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.236-246
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• 2016

The aim of this study was to develop an analytical method for the determination of pyribencarb and its metabolite KIE-9749 in agricultural commodities. The experiment was performed with a range of concentrations $0.05{\sim}2.5{\mu}g/g$ in apple, green pepper, potato, hulled rice, soybean, pear, peach, grape and cucumber. Each samples were extracted with acetone and cleaned by dichloromethane/saline water partition and purified with Florisil solid phase extraction (SPE) cartridge and aminopropyl SPE cartridge. Pyribencarb and KIE-9749 were separated and quantified by HPLC/UVD at 265nm using acetonitrile and water as mobile phase. The recoveries of pyribencarb and KIE-9749 were within 78.3~108.4% and 73.9~113.7% with RSD below 12.2% and 15.0%, respectively. The limits of quantification (LOQ) were both $0.05{\mu}g/g$. LC/ESI-MS/MS was optimized for confirmation of residue identity.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.420-423
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• 2010

The proanthocyanidin fraction was isolated from the wild grape (Vitis amurensis) peel and its antioxidant capacities were examined to promote the utilization of wild grape by-products. The 70% acetone crude extract of the wild grape peel was fractionated with hexane, ethyl acetate, and water. The ethyl acetate fraction was applied to a Sephadex LH-20 column chromatograph, which was eluted with 50% methanol, 75% methanol, and 75% acetone. The proanthocyanidin characteristics and contents of the isolated fractions were investigated by the vanillin-$H_2SO_4$ and BuOH-HCl methods. Fraction 6 had the highest proanthocyanidin content ($49.35{\pm}2.75\;g%$) among the isolated fractions. The antioxidant activities of the proanthocyanidin fraction were examined by DPPH radical scavenging, FRAP assay, and total phenolic contents. The FRAP values and total phenolic contents of the fractions ranged from 3.54 to 32.25 mmol/kg and from 4.48 to 50.80 g/100 g, respectively. The proanthocyanidin contents was strongly correlated with DPPH radical scavenging activities, FRAP values, and total phenolic contents.

• 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.