• Food Science and Preservation
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• v.19 no.2
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• pp.249-256
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• 2012

The changes in the volatile organic compounds in plum after its electron beam irradiation and storage were determined using the simultaneous distillation extraction method and gas chromatograph-mass spectrometry. There were 44, 46, 45, 47, and 38 volatile compounds in the 0-, 0.25-, 0.5-, 0.75-, and 1 kGy irradiated samples, respectively. Also, the volatile flavor components of the plum that was stored for 30 days were identified as 48, 40, 40, 39, and 40 components. The compositions of the volatile compounds of the control and irradiated samples showed a similarity after the storage. Especially, the more important volatile flavor of the plum was identified as hexanal of the C6compounds, (E)-2-hexenal and (Z)-3-hexenal. In particular, hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-ol increased in all the doses, where as hexanol and (E)-2-hexen-1-ol decreased. Among the lactone compounds, ${\gamma}$-hexalactone, ${\gamma}$-octalactone, and ${\gamma}$-decalactone were identified during the storage period in the raw samples. Hexanonic acid and 2-hexenoic acid were not identified during the storage of the samples, and 2-methylprrole was detected only when the storage samples were irradiated at a dose higher than 0.5kGy. Therefore, it was shown that there was no effect on the variation of the volatile organic component suntil 1 kGy in the plum was irradiated with an electron beam.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.845-854
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• 2009

There has been increased concern regarding the release of antibiotics to different environmental compartments due to the possibility of the development of antibiotic resistant bacteria. However, limited information is available regarding the occurrence, fate, and transport of antibiotics in Korea in both the aqueous phase and in solid phases such as sediment and soil. Therefore, this study was conducted to monitor the concentration of released antibiotics in surface water, sediment, and soil adjacent to a cattle manure composting facility in Korea. Specifically, the following six antibiotics were monitored: tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC), sulfamethazine (SMT), sulfamethoxazole (SMX), and sulfathiazole (STZ). To extract and quantify the antibiotics from different environmental compartments, solid phase extraction (SPE) and high performance liquid chromatography mass spectrometry (HPLC/MS) techniques were adopted. The concentration of the six antibiotics ranged from below the detection limit (BDL) to 0.71 ${\mu}g$/L in surface water, from BDL to 27.61 ${\mu}g$/L in sediment, and from 0.12 to 157.33 ${\mu}g$/L in soil. In addition, higher concentrations of antibiotics were observed in surface water and sediment at locations closer to the composting facility indicating that composting is the source of the antibiotics found in the environment. Furthermore, higher concentrations of antibiotics were observed in the solid phase (sediment and soil) than the aqueous phase. These findings indicate that the possibility of antibiotic resistant bacteria is increased because such bacteria are more stable in the solid phase. Overall, longterm monitoring of the aqueous phase and solid phase is necessary to gain a better understanding of the impact of antibiotics from source on the environment in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1239-1245
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• 2005

Hallabong peel oils grown in open field and green house were extracted by hand-pressing flavedo and collected on ice. Volatile flavor components of Hallabong peel oils were identified and compared by using gas chromatography and mass- spectrometry. Forty-four flavor components were identified in open field oil and 45 flavor components in green house oil. (E) -Limonene-1,2-epoxide and neral were identified only in Hallabong oil grown in open field, on the other hand, $\beta$-cubebene, $\beta$-elemene and decyl acetate were detected only in green house oil. Limonene was the most abundant component in both oils as more than 86$\%$ of peak weight, followed by sabinene (1.8$\~$ 3.6$\%$) and myrcene (2.4$\~ $2.6$\%$). The difference of the volatile profile between open field and green house oils were significantly characterized by identification and quantity of alcohol group. The total alcohols in open field and green house oils accounted for 1.8$\%$ and 0.8$\%$, respectively. Among alcohols, the level of linalool was relatively high in open field oil (1.2$\%$), however, it accounted for 0.5$\%$ in green house oil. Flavor properties of fresh Hallabong peel and flesh were also examined by sensory evaluation. Flavor properties of fresh Hallabong grown in open field were relatively stronger on both peel and flesh by sensory analysis. Sweetness was strong in Hallabong flesh from open field, and sourness in that from green house. The sensory evaluation of the preference in consideration of taste and aroma was significantly high in Hallabong grown in open field (p<0.01). From the present study, the stronger flayer properties and the preference of Hallabong from open field by sensory evaluation seem to be associated with the high level of linalool in its peel oil, and the composition of monoterpene hydrocarbons such as sabinene and (E) -$\beta$ -ocimene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1758-1763
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• 2012

This study was conducted to compare fragrance and volatile chemicals of essential oils in Gom-chewi (Ligularia fischeri) and Handaeri Gom-chewi (Ligularia fischeri var. spicifoprmis). Essential oils were extracted by steam distillation of leaves of Gom-chewi (GC) and Handaeri Gom-chewi (HGC), after which samples were collected by solid-phase micro extraction and the compositions of the essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). The yields of the essential oils in GC and HGC were 0.12% and 0.04%, respectively, and the threshold levels of the essential oils in GC and HGC were 0.01% and 0.1%, respectively. There were 19 constituents of the essential oil of Gom-chewi: 14 carbohydrates, 4 alcohols, and 1 acetate, and the major constituents were L-${\beta}$-pinene (36.02%), D-limonene (25.64%), ${\alpha}$-pinene (24.85%) and ${\beta}$-phellandrene (5.39%). In the essential oil of HGC, 25 constituents were identified: 17 carbohydrates, 4 alcohols, 3 acetates, and 1 N-containing compound, and the major constituents of HGC were D-limonene (39.74%), L-${\beta}$-pinene (35.43%) and ${\alpha}$-pinene (11.94%). The minor constituents of HGC were ${\rho}$-cymene, ${\gamma}$-muurolene, ${\gamma}$-cadinene, germacrene D, ingol 12-acetate and butyl 9,12,15-octadecatriene and nimorazole were not identified in the GC essential oil. Overall, the results showed that the fragrance and chemical compositions of essential oils in GC and HGC differed, suggesting that both essential oils could be used for the development of perfumery products.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.120-132
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• 2021

Although the development of high-Nickel is being actively carried out to solve the capacity limitation and the high price of raw cobalt due to the limitation of high voltage use of the existing LiCoO₂, the deterioration of the battery characteristics due to the decrease in structural stability and increase of the Ni content. It is an important cause of delaying commercialization. Therefore, in order to increase the high stability of the Ni-rich ternary cathod material LiNi_0.6Co_0.2Mn_0.2O₂, precursor Ni_0.6Co_0.2Mn_0.2-x(OH)₂/xTiO₂ was prepared using a nanosized TiO₂ suspension type source for uniform Ti substitution in the precursor. It was mixed with Li₂CO₃, and after heating, the cathode active material LiNi_0.6Co_0.2Mn_0.2-xTi_xO₂ was synthesized, and the physical properties according to the Ti content were compared. Through FE-SEM and EDS mapping analysis, it was confirmed that a positive electrode active material having a uniform particle size was prepared through Ti-substituted spherical precursor and Particle Size Analyzer and internal density and strength were increased, XRD structure analysis and ICP-MS quantitative analysis confirmed that the capacity was effectively maintained even when the Ti-substituted positive electrode active material was manufactured and charging and discharging were continued at high temperature and high voltage.

• 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.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.175-182
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• 2022

Heavy metals can be intentionally or unintentionally introduced into plastic food utensils, containers, and packaging (PFUCP) as additives or contaminants, which can be ingested with food by humans. Here, seven-heavy metals (lead, cadmium, nickel, chromium, antimony, copper, and manganese) with toxicity concerns were selected, and risk assessment was done by establishing their migration from 137 PFUCP products made of 16 materials distributed in Korea. Migration of heavy metals was examined by applying 4% acetic acid as a food simulant (70℃, 30 minutes) to the PFUCP products. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the analysis of migrated heavy metals, and the reliability of quantitative results was confirmed by checking linearity, LOD, LOQ, recovery, precision, and expanded uncertainty. As a result of monitoring, heavy metals were detected at a level of non-detection to 8.76 ± 11.87 ㎍/L and most of the heavy metals investigated were only detected at trace amounts of less than 1 ㎍/L on average. However, antimony migrated from PET products was significantly higher than other groups. Risk assessment revealed that all the heavy metals investigated were safe with a margin of exposure above 311. Collectively, we demonstrated that heavy metals migrated from PFUCP products distributed in Korea appear to be within the safe range.

• Analytical Science and Technology
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• v.36 no.6
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• pp.267-280
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• 2023

This study investigated the contents of Pb, Cd, As, and Hg for 4333 samples with 2 09 types of herbal medicines distributed in Seoul area from 2019 to 2021, and evaluated risk assessment according to medicinal part used and origin. The contents of heavy metals were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and mercury analyzer. The average contents (mg/kg) of heavy metals by medicinal parts were 0.123 to 1.290 for Pb, 0.018 to 0.131 for Cd, 0.034 to 0.290 for As, and 0.003 to 0.015 for Hg. The contents of Pb were higher in Leaves and Whole Herbs (above-ground part) than underground part (Radix & Rhizoma) (ANOVA-test, p < 0.05). The contents of Cd were high in Leaves, Radix & Rhizoma, and Stems & Woods (ANOVA-test, p <0 .05), and exceeded regulatory limits in various types. Levels of Pb, Cd concentrations exceeding regulatory limits were observed in 8, 22 samples (8, 14 types). No sample exceeded regulatory limits of As and Hg. In the comparison between countries of origin, the contents of Cd, As, and Hg were high in imported herbal medicines (t-test, p < 0.05). As a result of the risk assessment, except for Thujae Orientalis Folium and Spirodelae Herba, the MOE values of Pb were all 1 or more, and most samples were safe. The Hazard Index (HI) for Cd, As, and Hg were evaluated to be less than 100 % even if the risk (%) of each heavy metal was added, and the risk from taking herbal medicines was evaluated to be safe.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.163-170
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• 2024

Red ginseng is manufactured as a health-functional food and is also present in various food types and in different product forms. However, there is currently no standardized regulation of ginsenoside content in foods containing red ginseng. In the present study, we analyzed the ginsenoside content of 66 red ginseng-containing foods and 35 health-functional foods collected online and directly from the market. The ginsenoside content was assessed using liquid chromatography (LC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The ginsenoside content of the various food types ranged 0.0 (not detected)-71.567 mg per daily intake of foods containing red ginseng. Sugar-preserved foods had the highest ginsenoside content, followed by solid teas, liquid teas, and red ginseng beverages. For health-functional foods, the ginsenoside content ranged 3.4-58.5 mg per daily intake, with levels ranging 83-607% of the indicated amounts. All values met the established standards. Upon comparing red ginseng health-functional foods and red ginseng-containing foods, the average ginsenoside content was determined to be 18.21 and 8.79 mg, respectively, thus being nearly twice as high in health-functional foods. However, there was a minimal difference between the ginsenoside content of red and black ginseng, with values of 11.84 and 12.63 mg, respectively. These findings provide insights on the variations in ginsenoside content of red and black ginseng in various food forms. This information is expected to be valuable for future regulations and consumer choice of products containing red ginseng.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.241-246
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• 2007

Purpose: $[^{11}C]6-OH-BTA-1$ ([N-methyl-$^{11}C$]2-(4'-methylaminophenyl)-6-hydroxybenzothiazole, 1), a -amyloid imaging agent for the diagnosis of Alzheimer's disease in PET, can be labeled with higher yield by a simple loop method. During the synthesis of $[^{11}C]1$, we found the formation of by-products in various solvents, e.g., methylethylketone (MEK), cyclohexanone (CHO), diethylketone (DEK), and dimethylformamide (DMF). Materials and Methods: In Automated radiosynthesis module, 1 mg of 4-aminophenyl-6-hydroxybenzothiazole (4) in 100 l of each solvent was reacted with $[^{11}C]methyl$ triflate in HPLC loop at room temperature (RT). The reaction mixture was separated by semi-preparative HPLC. Aliquots eluted at 14.4, 16.3 and 17.6 min were collected and analyzed by analytical HPLC and LC/MS spectrometer. Results: The labeling efficiencies of $[^{11}C]1$ were $86.0{\pm}5.5%$, $59.7{\pm}2.4%$, $29.9{\pm}1.8%$, and $7.6{\pm}0.5%$ in MEK, CHO, DEK and DMF, respectively. The LC/MS spectra of three products eluted at 14.4, 16.3 and 17.6 mins showed m/z peaks at 257.3 (M+1), 257.3 (M+1) and 271.3 (M+1), respectively, indicating their structures as 1, 2-(4'-aminophenyl)-6-methoxybenzothiazole (2) and by-product (3), respectively. Ratios of labeling efficiencies for the three products $([^{11}C]1:[^{11}C]2:[^{11}C]3)$ were $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ in MEK, $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$ in CHO, $9.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$ in DEK and $7.6{\pm}0.5%:0.0%:0.0%$ in DMF, respectively. Conclusion: The labeling efficiency of $[^{11}C]1$ was the highest when MEK was used as a reaction solvent. As results of mass spectrometry, 1 and 2 were conformed. 3 was presumed.