• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.244-252
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• 2005

This study was performed far development of new analytical method of beet red in foods. In this study, analysis of beet red in foods has been carried out by detection of betanine and isobetanine, the main color component of beet red as indicator compounds. The qualitative analysis technique consisted of clean-up of the colors with a $C_{18}$ cartridge, separation of the colors by cellulose TLC plate using acetone:3-methyl-1-butanol:distilled water (7:7:6) as a solvent system. Also, the quantitative analysis was performed using X-terra RP at wavelength 538 nm and $0.1\%$ phosphoric acid : methanol (90:10) as a solvent. The quantitative results of beet .ed were as follows:900.22$\∼$27701.60 $\mu$g/g for 60 item in nutrient supplement food, $21.95\∼713.40{\mu}g/g$ for 30 items and N.D. for 18 items in cindy, and $155.85{\∼}505.37{\mu}g/g$ for 12 items in ice creams, $43.52\∼64.75{\mu}g/g$ for 18 items and N.D. for 54 item in sauce, N.D. for 12 items in retort food.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.246-254
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• 2017

Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.109-116
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• 1971

The study involved determination of resistance levels of spider mites to Metasystox, Folidol and C-8514 using slide dip technique: a feid trial of alternative acaricides using an O/P resistant strain. 1. Resistant strains of two-spotted spider mite( Tetranychus urticae Koch) were collected from Taegu, Kyungsan, Chunchun, Yesan, Suwon, Osan and Chungju, and kept in the glasshouse through the experiments. Resistant strains of European red mite (Panonychus ulmi Koch) were collected from Chungju, Taegu, Yesan, Chunchun, Suwon and Whasung, and Wonju susceptible was collected. Immediately after collection, tests were applied. All strains except susceptible populations had regularly been sprayed with Organo-phosphates including Parathion (or Folidol), Metasystox, Phenkapton and Trithion for more than the ten Bast years; and Organo-chlorines such as Kelthane and C-8514 more than five years. Comparisons of the resistant strains and susceptible strains at the $LC_50$ values are as follows: a. With Metasystox, resistance levels of the Chungju, Taegu, Yesan, Chunchun and Suwon resistant strains of P. ulmi were respectively, 96,52,4,3 and 2, times as resistant as the Wonju susceptible strain. b. With Folidol, resistance levels of the Chungju, Chunchun, Yesan, Whasung and Suwon strains of P. ulmi showed respectively, 126, 48, 33, 30 and 6-fold resistance levels over the susceptible strain. c. With C-8514, resistance levels of the Taegu, Suwon, Whasung and Chungju strains of P. ulmi were 42, 31, 30 and 20 times greater than the susceptible strain, respectively. d. With Metasystox, resistance levels of the Taegu, Chunchun, Yesan and Suwon, strains of T urticae were respectively, 32,29,25 and 17 times as resistant as the susceptible strain. e. With C-8514, resistance levels of the Taegu, Chungju and Kyungsan strains of T. urticae showed respectively, 59, 29 and 19-fold resistance levels over the Osan strain. 2. Field trials were carried out to assess the toxicities of eleven alternative materials which would be used for control of O/P resistant strain of Panonychus ulmi. The acaricide groups represented were 2 Organo-chlorines (Kelthane MF and Prethylen), 1 carbamate (Furadan), 1 nitrophenyl (Morocide), 1 carbonate (Morestan), 1 tin(Plictran), 1 fluorine (Nissol), 2 mixtures (Fundal and Banmite) and Organo-phosphate (Phenkapton). Of all acaricides tested Kelthane, Plictran, Fundal and Morestan were the most effective; fol]owed by Banmite, Furadan, Prethylen and Nissol. Sumite and Morocide were intermediate, but Phenkapton(Organo-phosphate) was very poor. In other words, a first application of the above outstanding materials gave very high degrees of control of O/P resistant population of European red mite for about 7 to 12 days. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage to apple trees by any of the acaricides tested of the concentrations used.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.186-193
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• 2016

An analytical method was developed for the determination of oxathiapiprolin in agricultural commodities. Oxathiapiprolin is a new oomycide (fungicide of piperidinyl thiazole isoxazoline class) which controls downy mildew in cucurbits caused by Pseudoperonospora cubensis (oomycete plant pathogen). Agricultural commodities were extracted with acetonitrile and partitioned with dichloromethane to remove the interference, adjusting pH between 9 and 10 by 1 N sodium hydroxide. After purification by silica SPE cartridge to clean up the interference of organic compounds, they were finally quantified by HPLC-UVD (high performance liquid chromatograph ultraviolet detector) using a wavelength at 260 nm and confirmed by LC-MS (liquid chromatograph mass spectrometer) in electro-spray ionization positive ion mode. The standard calibration curve was linear with coefficients of determination ($r^2$) 1.00 over the calibration ranges (0.025-2.5 mg/L). Recoveries were ranged between 86.7 to 112.7%, with relative standard deviations less than 10% at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates. The overall results were determined and estimated according to the CODEX guidelines (CAC/GL40). The proposed method for determination of oxathiapiprolin residues in agricultural commodities can be used as an official method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.171-181
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• 2012

Lysine is the first limiting essential amino acid in cereals for humans and monogastric animals, although its content is generally low. A chemically induced high-lysine barley mutant, M98, has an agronomically undesirable shrunken endosperm trait. In order to obtain detailed insight into the atypical traits of M98 grains, we characterized amino acid composition and protein profiles of M98 and its parent cultivar Chalssalbori. Among a total of 16 amino acids, the percentage of each of the 7 amino acids, including lysine, was 1.2~1.8 times higher in M98, comparing to Chalssalbori. The percentage of proline and its precursor, glutamic acid, in M98 was about the half of that of the amino acids in Chalssalbori, but arginine synthesized from glutamic acid was 1.8 times higher in M98, compared that in the parent cultivar. Theses results indicated that the mutation in M98 grains might alter the proportion of amino acids linked to each other in a biosynthetic pathway. A comparison of grain proteome profiles between Chalssalbori and M98 revealed 70 differentially expressed protein spots, where 45 protein spots were up-regulated and 25 protein spots down-regulated in M98 compared to those in Chalssalbori. Of these changed protein spots, 53 were identified using nano-electrospray ionization liquid chromatography mass spectrometry. Most of these identified proteins were involved in various biological processes. In particular, 28 protein spots such as ${\beta}$-amylase, serpins and B3-hordein were identified as proteins associated with the atypical traits of M98. It was thought that a genetic study on the unique protein profile of M98 would be needed to develop an agronomically feasible barley cultivar with high-lysine trait.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.106-116
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• 2007

Pesticide, chlorfluazuron was subjected to determine the safety of terminal residues at the harvesting date of perilla leaves cultivated in plastic house. After the pesticide applied on a foliar spray in 2005 and 2006, leaf persistence of its residue was analysed for 10 days before leaf harvest. The degradation rate of chlorfluazuron in the leaf was 32.3 %(standard application), 43.6 %(double application) and 78.0 %(standard), 80.4 %(double) at second and tenth day, respectively, under analysis of GC/ECD in 2005. The degradation rate of chlorfluazuron in the leaf was 33.1 %(GC/ECD analyze), 34.0 %(HPLC/UVD analyze) and 77.9 %(GC/ECD), 78.4 %(HPLC/UVD) at second and tenth day, respectively, under the standard level of pesticide in 2006. The biological half-life of the chlorfluazuron residue was estimated by the regression equation calculated from daily dissipation of pesticide in the perilla leaves. The longest half-life of the chlorfluazuron residue in perilla leaves was 5.5 days. The maximum residual limit(MRL) for chlorfluazuron based on the longest half-life was estimated 2.0ppm at harvesting day, 2.5ppm at second day and 7.1ppm at tenth day before leaf harvesting of perilla.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.134-167
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• 2022

This study conducted monitoring of flora and vegetation in order to utilize basic data for forest wetland conservation targeting outstanding forest wetlands located in the eastern part of Jeonnam Province. The survey was carried out for a total of 54 times from May 2020 to October 2020, 1-2 times each for each season. The vascular plants of outstanding forest wetland in eastern Jeollanam-do were 93 families, 251 genera, 336 species, 5 subspecies, 47 varieties, 7 forma, and a total of 395 taxa. This was about 8.5% of 4,641 species of vascular plants in Korea Peninsula. A total of 8 taxa and 12 taxa were identified Korea endemic plants and rare plants respectively. A total of 68 taxa and 19 taxa of floristic target plants and invasive alien plants were classified each. the naturalized Index was 4.83% and the urbanized Index was 5.90%. As a result of the analysis by wetland type of the forest wetlands, obligate upland plants were the highest in the forest wetlands in the eastern Jeonnam province (61.4%), with unclassified wetland plants 19.1%, facultative wetland plants 8.2%, and obligate wetland plants 4.6%, facultative upland plants 4.5%, and facultative plants 2.3% were confirmed in the order.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.853-865
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• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.

• Analytical Science and Technology
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• v.35 no.3
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• pp.136-142
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• 2022

According to media reports, the carcasses of euthanized abandoned dogs were processed at high temperature and pressure to make powder, and then used as feed materials (meat and bone meal), raising the possibility of residuals in the feed of the anesthetic ketamine and dexmedetomidine used for euthanasia. Therefore, a simultaneous analysis method using QuEChERS combined with high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was developed for rapid residue analysis. The method developed in this study exhibited linearity of 0.999 and higher. Selectivity was evaluated by analyzing blank and spiked samples at the limit of quantification. The MRM chromatograms of blank samples were compared with those of spiked samples with the analyte, and there were no interferences at the respective retention times of ketamine and dexmedetomidine. The detection and quantitation limits of the instrument were 0.6 ㎍/L and 2 ㎍/L, respectively. The limit of quantitation for the method was 10 ㎍/kg. The results of the recovery test on meat and bone meal, meat meal, and pet food showed ketamine in the range of 80.48-98.63 % with less than 5.00 % RSD, and dexmedetomidine in the range of 72.75-93.00 % with less than 4.83 % RSD. As a result of collecting and analyzing six feeds, such as meat and bone meal, prepared at the time the raw material was distributed, 10.8 ㎍/kg of ketamine was detected in one sample of meat and bone meal, while dexmedetomidine was found to have a concentration below the limit of quantitation. It was confirmed that the detected sample was distributed before the safety issue was known, and thereafter, all the meat and bone meal made with the carcasses of euthanized abandoned dogs was recalled and completely discarded. To ensure the safety of the meat and bone meal, 32 samples of the meat and bone meal as well as compound feed were collected, and additional residue investigations were conducted for ketamine and dexmedetomidine. As a result of the analysis, no component was detected. However, through this investigation, it was confirmed that some animal drugs, such as anesthetics, can remain without decomposition even at high temperature and pressure; therefore, there is a need for further investigation of other potentially hazardous substances not controlled in the feed.

• Analytical Science and Technology
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• v.36 no.6
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• pp.291-299
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• 2023

The benzo[a]pyrene in edible oils is extracted using methods such as Liquid-liquid, soxhlet and ultrasound-assisted extraction. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these drawbacks, this study attempted to improve the current complex benzo[a]pyrene analysis method by applying the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method that can be analyzed in a simple and short time. The QuEChERS method applied in this study includes extraction of benzo[a]pyrene into n-hexane saturated acetonitrile and n-hexane. After extraction and distribution using magnesium sulfate and sodium chloride, benzo[a]pyrene is analyzed by liquid chromatography with fluorescence detector (LC/FLR). As a result of method validation of the new method, the limit of detection (LOD) and quantification (LOQ) were 0.02 ㎍/kg and 0.05 ㎍/kg, respectively. The calibration curves were constructed using five levels (0.1~10 ㎍/kg) and coefficient (R²) was above 0.99. Mean recovery ratio was ranged from 74.5 to 79.3 % with a relative standard deviation (RSD) between 0.52 to 1.58 %. The accuracy and precision were 72.6~79.4 % and 0.14~7.20 %, respectively. All results satisfied the criteria ranges requested in the Food Safety Evaluation Department guidelines (2016) and AOAC official method of analysis (2023). Therefore, the analysis method presented in this study was a relatively simple pretreatment method compared to the existing analysis method, which reduced the analysis time and solvent use to 92 % and 96 %, respectively.