• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.166-177
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• 2022

The Shiveet Khairkhan is located on Tsengel Som in the middle of Bayan-ulgi Aimag in the Altai region. Various remains have been identified, and it has been found to be an important area of the Eurasian steppe. In this study, the characteristics of textile fibers and dyes excavated from the tombs of the 1st~3rd century Xianbei period in the sites of Shiveet Khairkhan, Mongolia were investigated. As a result of analysis using optical microscopic observation and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) for fiber identification, green and yellow fabrics were identified as silk fabrics. To investigate the properties of the dye, the surface reflectance of the dyed fabric was measured using an fiber optic reflectance spectrophotometer for non-destructive analysis. The green fabric appeared similar to the reflection spectrum of indigo dye. In addition, as a result of component analysis using gas chromatography-mass spectrometry, isatin and indigotine were detected. Isatin and indigotine are characteristic components of indigo dye, and it was found that the green fabric of the tombs of the Xianbei period was dyed using indigo dye. It was difficult to identify the type of dye in the yellow fabric as a result of reflectance spectrum and gas chromatography analysis. Indigo plants are a dye used for blue dyeing from thousands of years ago, and many species are distributed around the world. It was confirmed that the fabric was relatively well preserved and indigo dye was used for the green Jikryeongui (garment with a straight collar) in the ancient tomb of the Xianbei period about 1,800 years ago, even though it was buried for a long time. Scientific investigation of textile cultural heritage is an essential process for conservation treatment, restoration, exhibition, and the creation of a conservation environment. It is expected that related research will be activated in the future and will be helpful in interpreting the living culture at the time, preserving textiles, and a conservation environment.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.537-545
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• 2011

This study was conducted to obtain basic information on physiological and proteomic responses of barley seedlings to salt stress. Shoot dry weight decreased significantly as the level of soil salinity increased. Salt stress-induced decrease of relative shoot dry weight was lower in cv. "Sanglok" than in cv. "Sunwoo". Under the salt stress, SPAD value decreased, and the value was higher in cv. "Sanglok" than in cv. "Sunwoo". Sodium ion content in the leaves increased as NaCl concentration increased, and the content was higher in cv. "Sunwoo" than in cv. "Sanglok". The K⁺/Na⁺ ratio was higher in cv. "Sanglok" than in cv. "Sunwoo". Salt stress-induced alterations in protein expression of the leaves were detected by two dimensional electrophoresis, and 47 protein spots showing altered expression were selected. Among the selected protein spots, 17 protein spots were up-regulated and 28 spots down-regulated in cv. "Sanglok". In cv. "Sunwoo", 14 protein spots were up-regulated and 27 spots down-regulated. Out of 47 deferentially expressed protein spots, 18 protein spots were identified using mass spectrometry and NCBI protein database. Among the identified proteins, ten proteins are known to be involved in various stress responses, but the others are not directly involved in stress responses.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.281-302
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• 2023

Carbon is not only an essential element for life but also a key player in climate change. The radiocarbon (¹⁴C) analysis using accelerator mass spectrometry (AMS) is a powerful tool not only to understand the carbon cycle but also to track pollutants derived from fossil carbon, which have a distinct radiocarbon isotope ratio (Δ¹⁴C). Many studies have reported Δ¹⁴C of carbon compounds in streams, rivers, rain, snow, throughfall, fine particulate matter (PM_2.5), and wastewater treatment plant effluents in South Korea, which are reviewed in this manuscript. In summary, (1) stream and river carbon in South Korea are largely derived from the chemical weathering of soils and rocks, and organic compounds in plants and soils, strongly influenced by precipitation, wastewater treatment effluents, agricultural land use, soil water, and groundwater. (2) Unprecedentedly high Δ¹⁴C of precipitation during winter has been reported, which can directly and indirectly influence stream and river carbon. Although we cannot exclude the possibility of local contamination sources of high Δ¹⁴C, the results suggest that stream dissolved organic carbon could be older than previously thought, warranting future studies. (3) The ¹⁴C analysis has also been applied to quantify the sources of forest throughfall and PM_2.5, providing new insights. The ¹⁴C data on a variety of ecosystems will be valuable not only to track the pollutants derived from fossil carbon but also to improve our understanding of climate change and provide solutions.

• 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.38 no.5
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• pp.361-372
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• 2023

Organotin pesticide is used as an acaricide in agriculture and may contaminate livestock products. This study aims to develop a rapid and straightforward analytical method for detecting organotin pesticides, specifically azocyclotin, cyhexatin, and fenbutatin oxide, in various livestock products, including beef, pork, chicken, egg, and milk, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction process involved the use of 1% acetic acid in a mixture of acetonitrile and ethyl acetate (1:1). This was followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium chloride. The extracts were subsequently purified using octadecyl (C₁₈) and primary secondary amine (PSA), after which the supernatant was evaporated. Organotin pesticide recovery ranged from 75.7 to 115.3%, with a coefficient of variation (CV) below 25.3%. The results meet the criteria range of the Codex guidelines (CODEX CAC/GL 40). The analytical method in this study will be invaluable for the analysis of organotin pesticides in livestock products.

• 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.

• Food Science and Preservation
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• v.30 no.1
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• pp.109-121
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• 2023

This study was conducted to evaluate vitamin D intake of Koreans in a total diet study (TDS) and to determine the effect of irradiation on vitamin D synthesis in mushrooms. For analysis, sample were saponified and extracted with hexane, and vitamin D was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on the validation results, the recovery of the National Institute of Standards and Technology (NIST) standard reference sample (SRM) 1849a was 96.7% and the z-score of -1.6 was obtained by the Food Analysis Performance Assessment Scheme (FAPAS) proficiency test (PT) 21115. Vitamin D₂ was not detected in any samples, and the highest level of vitamin D₃ was detected in mackerel and anchovies ranging from 24.2 to 120.2 ㎍/kg. The mean daily intake of vitamin D was 0.99 ㎍/day, as estimated from the vitamin D contents of the analyzed foods and their corresponding intake. The adequate intake (AI) of vitamin D based on the Dietary reference intakes for Koreans provided by the Ministry of Health and Welfare is 5-15 ㎍/day for Koreans aged 6 to 75 years. Compared with this AI, vitamin D intake of Koreans estimated in this study was inadequate. For that, the increased vitamin D content in ultraviolet (UV)/sun light irradiated mushrooms warrants further research to increase vitamin D intake of Koreans through diet.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.250-259
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• 2024

In this study, we investigated in pesticide residues and heavy metals in fermented liquor products (wine, beer, makgeolli). Targeted analysis of 400 pesticide residues in the sample was performed using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method, followed by gas chromatography-tandem mass spectrometry (MS/MS) and LC-MS/MS. The contents of heavy metals (Pb, Cd) were determined by ICP-MS using the microwave method. The mercury was measured using a mercury analyzer. From the analysis of 150 cases, 102 (68.0%) cases of fermented liquor were detected, and 35 pesticide residues (including metalaxyl, mandipropamid, azoxystrobin, and fenhexamid) were detected among the 400 pesticide residues tested. Pb, Cd, and Hg were tested in 150 samples. Lead was detected in 73 samples (48.7%), cadmium in 9 samples (6.0%), and mercury in 36 samples (24.0%). Exposure assessment was conducted to determine the safety of the detected pesticide residues and heavy metals. According to this assessment, the pesticide residues and heavy metals showed very low %ADI values (less than 1%).

• 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.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.130-140
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• 2014

Recently, some of the previous studies reported that tolclofos-methyl is still exist in ginseng cultivated soil, even though it is has been banned for ginseng. Therefore, the current study was aimed to examine the levels of absorption and translocation of tolclofos-methyl from ginseng cultivated soil to ginseng root and leaf stem for the period of 1 year. For this study, ginseng plants were transplanted in pots and treated with $5.0mg\;kg^{-1}$ of tolclofos-methyl (50% WP). At the end of each interval periods (every three months) the samples (soil, roots and leaf stems) were collected and analyzed the absorption and translocation levels of tolclofos-methyl using gas chromatography and mass spectrometry (GC-MS). The limit of quantitation of tolclofos-methyl was found to be $0.02mg\;kg^{-1}$ and 70.0~120.0% recovery was obtained with coefficient of variation of less than 10% regardless of sample types. In this study, a considerable amount of translocation of tolclofos-methyl residues were found in soil (4.28 to $0.06mg\;kg^{-1}$), root (7.09 to $1.54mg\;kg^{-1}$) and leaf stem (0.79 to $0.69mg\;kg^{-1}$). The results show that the tolclofos-methyl was absorbted and translocated from ginseng cultivated soil to ginseng root and ginseng leaf stem and found to be decreased time-coursely. Secondly, we were also analyzed soil, root and leaf stems samples from Hongcheon, Cheorwon, Punggi and Geumsan by GC-MS/MS (172 pesticides), LC-MS/MS (74 pesticides). In this study, 43 different pesticides were detected ($0.01{\sim}7.56mg\;kg^{-1}$) in soil, root and leaf stem. Further, tolclofos-methyl was detected 4 times separately in root sample alone which is less ($0.01{\sim}0.05mg\;kg^{-1}$) than their maximum residual limit (MRL) in ginseng. Consequently, the results from both studies indicate the residues of tolclofos-methyl found in ginseng cultivated soil and ginseng ensuring their safety level. Moreover, long-term evaluations are needed in order to protect the soil as well as ginseng free from tolclofos-methyl residues.