• Analytical Science and Technology
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• v.34 no.6
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• pp.259-266
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• 2021

Cannabis (Marijuana) is one of the most widely used drugs in the world, and its distribution has been controlled in South Korea since 1976. Identification of 11-nor-Δ⁹-carboxy-tetrahydrocannabinol (THCCOOH) in urine can provide important proof of cannabis use, and it is considered scientific evidence in the forensic field. In this study, we describe a simultaneous quantitative method for identifying THCCOOH and THCCOOH-glucuronide in urine, using simple liquid-liquid extraction (LLE), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). THCCOOH-D₃ and THCCOOH-glucuronide-D₃ were used as internal standards. Validation results of the matrix effect, as well as recovery, linearity, precision, accuracy, process efficiency, and stability were all satisfactory. No carryover, endogenous or exogenous interferences were observed. The limit of detection (LOD) of THCCOOH and THCCOOH-glucuronide were 0.3 and 0.2 ng/mL, respectively. The developed method was applied to 28 authentic human urine samples that tested positive in immunoassay screening and gas chromatography/mass spectrometry (GC/MS) tests. The ranges of concentrations of THCCOOH and THCCOOH-glucuronide in the samples were less than LOQ~266.90 ng/mL and 6.43~2133.03 ng/mL, respectively. The concentrations of THCCOOH-glucuronide were higher than those of THCCOOH in all samples. This method can be effectively and successfully applied for the confirmation of cannabinoid use in human urine samples in the forensic field.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.87-94
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• 1996

한국산 동백나무겨우살이(Pseudixus japonicus) 추출물의 암치료를 위한 생약으로서 활성 유효성을 검증하기 위하여 메탄올, 석유에테르, 클로로포름, 초산 에틸 용매로 순차적으로 추출하여 겨우살이 추출물의 다섯 가지 분획을 얻어, 이에 대하여 in vitro로 1차와 2차 검색 시스템을 사용해 항암활성 성분을 체계적으로 검색하였다. 다섯 가지 분획 중 클로로포름 가용성 분획이 1차 검색 세포인 $P388D_1$에 대해 가장 높은 항암활성을 나타내어 MSB1, NIH/3T3, SNU-1, SNU-C2A 등 2차 검색 시스템에 대해 클로로포름 가용성 분획의 항암활성을 다양한 농도하에서 비교 검색하였다. 혈액암 세포중 특히 $P388D_1$의 생장이 클로로포름 추출물에 의해 강하게 저해되었으며, 형질전환된 생쥐의 태아 섬유아세포와 사람의 대장암, 위암세포들도 어느 정도의 생육저해를 나타내었다. 이 클로로포름 가용성 분획의 주성분은 원소분석, 발색시약과의 반응, IR, GC-MS, $^{13}C$-NMR의 스펙트럼의 결과로 세 종류의 알칼로이드 화합물로 확인되었고, 부성분으로는 지방산 메틸 에스테르와 프탈라이드 화합물이 MS 스펙트럼을 통해 동정되었다.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.396-402
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• 2012

The chemical composition, anti-porcine epidemic diarrhea virus (PEDV) activity and antimicrobial activity of Artemisia dubia essential oil were evaluated in this study. Fifty eight compounds from A. dubia essential oil were identified through analysis by gas chromatography-mass spectrometry (GC-MS). The major constituents of the oil were camphor (17.18 %), germacrene-D (15.70%), trans (${\beta}-$) racaryophyllene (6.79%), ene thujones (6.57%), 1, 8-cineole (5.94%) and camphene (5.08%). The essential oil was evaluated for antiviral activity against PEDV in Vero cells using a cytopathic effect (CPE) reduction method. The oils actively inhibited PEDV replication with a 50% inhibitory concentration ($IC_{50}$) of 43.7 ${\mu}^3/mL$. The 50% cytotoxicity concentration ($CC_{50}$) of the oils was over 100 ${\mu}/mL$ and the derived therapeutic index was >2.3. Similar analysis of the ribavirin revealed that they have a relatively weaker efficacy when compared to the oils. The antimicrobial activity of the essential oil against 5 microorganisms was evaluated by the disc diffusion method. The essential oil exhibited antimicrobial activity against 5 tested microorganisms with a clear zone of 8-22 mm. Among the tested microorganisms, Streptococcus pyogenes was the most sensitive and Candida albicans the least. Therefore, in can be concluded that essential oils of A. dubia may have interesting applications for microbial control or the control of PEDV-derived diseases.

• Journal of Mushroom
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• v.21 no.4
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• pp.222-227
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• 2023

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70℃ for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70℃ for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 ㎍/g d.w. and 174.80 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 ㎍/g d.w. and 0.98~59.88 ㎍/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 ㎍/g d.w. and 176.17 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 ㎍/g d.w. and 1.96~15.77 ㎍/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

• 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 Applied Biological Chemistry
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• v.58 no.3
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• pp.197-199
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• 2015

The composition of the essential oil of Ligustrum japonicum leaves was determined by GC-MS analysis. The major constituents of L. japonicum leaf oil were germacrene D (40.50%), ${\alpha}$-pinene (13.63%), (-)-${\beta}$-elemene (6.42%), ${\beta}$-caryophyllene (5.73%), and $\delta$-cadinene (5.47%). The acaricidal activities of L. japonicum oil were evaluated against acaridae and pyroglyphid mites. In the fumigant bioassay, the $LD_{50}$ values of L. japonicum oil were 16.48, 12.38, and $15.63{\mu}g/cm^3$ against Tyrophagus putrescentiae, Dermatophagoides farinae, and D. pteronyssinus, respectively. In the contact bioassay, the $LD_{50}$ values of L. japonicum oil were 8.02, 5.02, and $7.67{\mu}g/cm^2$ against T. putrescentiae, D. farinae, and D. pteronyssinus, respectively.

• Analytical Science and Technology
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• v.25 no.3
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• pp.178-189
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• 2012

As phthalates classified as toxic to reproduction category 2 and endocrine disrupting chemicals were more strictly regulated as Substances of Very High Concern (SVHC) for authorization in under EU REACH and considered as priority substances in RoHS II, standardization of phthalate testing method is now being proposed in IEC 62321 of IEC TC 111 and the 2nd revision of KS M 1991 is also finished. In order to assist standardization activities related to phthalating testing, solvent extraction part of existing national standards were compared and verified. Recovery of DEHP (diethylhexyl phthalate) from PVC (polyvinyl chloride) by Soxhlet extraction increased in the order of methanol, toluene, dichloromethane and hexane from 46.9% to 95.3% as measured by GC-MS. Optimum extraction time was verified to be 6 hours using hexane. Recovery of DBP (dibutyl phthalate), BBP (butylbenzyl phthalate), and DEHP from different matrixes such as PVC, nitro cellulose, ABS (acrylonitrile butadiene styrene). and EPDM(ethylene propylene diene monomer) rubber were evaluated to be more than 90% up to 99%. The detection limits of phthalates in solvent extraction followed by GC-MS analysis were 0.08~0.3 ${\mu}g/mL$ in solution and 8~30 mg/Kg in polymeric samples. GC-MS analyses of phthalates were carried out using different solvent extraction based on the EN 14372, ASTM D 7083, Japanese test method (MHLW 0906-4) and KS M 1991, proving that equivalent recoveries ranging from 98%~99% were obtained. DBP and DEHP were detected in three consumer products such as a child toy, a power cable and manicure with the amount of 22~1,910 mg/kg.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.102-108
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• 2004

The present study was carried out to compare the composition of major essential oil components in the flue-cured tobacco produced by Korea, America, China, Brazil and Zimbabwe. Above 100 essential oil components were separated by GC and major 18 components of them, known to be important contributors to flue-cured tobacco flavor and smoke taste, were identified by GC/MS. Neophytadiene was major in quantities in the oils mostly and its composition in flue-cured tobacco produced by Korea, America, Zimbabwe, Brazil, and Unnam and Yenji region of China was 26.82\%,\;25.17\%,\;26.50\%,\;16.92\%,\;and\;18.75\%\;and\;14.87\%$, respectively. Megastigmatrienone, one of the major tobacco carotenoid degradation products was contained above $10\%$ in the oils of flue-cured tobacco produced by Korea and America, but, it was comprised about $5.66\%$ to 8.00 in Brazil, Zimbabwe, and Unnam and Yenji region of China. Damascenone is important to the aroma of tobacco as a crotenoid degradation products. Its amount in the oils was $3.31\%\;in\;Brazil,\;3.13\%\;in\;America,\;2.57\%\;in\;Zimbabwe,\;2.54%$ in Yenji of China, $2.00\%$ in Korea and $1.85\%$ in Unnam of China. These results can furnish the basic information capable of evaluating the quality value of flue-cured tobacco produced by various nations.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.156-162
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• 1994

To better understand the exact nature of the major toxic compound responsible for phytotoxicity of sorghum stem, the most toxic compound from the stem extract was isolated by rapid chromatography and subsequently purified by thin-layer chromatography(TLC) and high pressure liquid chromatography(HPLC). Of the eight fractions isolated by rapid chromatography, the fraction with solvent combinations of butanol (8) : acetic acid (1) : water (1) had the highest toxicity. Further separation of the fraction by TLC in a solvent mixture of butanol (24) : acetic acid (16.4) : water (7) : propanol (1) showed that the spot with an $R_f$ 0.71 had one major peak with retention time of 20.40 minutes. Upon subjecting gas chromatography and the HPLC fraction to the mass spectrometry, the toxic compound is probably one of the four compounds ; 1-methyl-1-(2-propynyl)-hydrazine, 1-aziridineethanol, 5-chloro-2-pentanone, and 2-(methylseleno)-ethanamine.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1087-1094
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• 2008

Diazinon is a phosphorothiate insecticide widely used in the world including Korea. This study investigates the feasibility of photolysis and photocatalysis processes for the degradation of diazinon in water. Both photolysis and photocatalysis reactiosn were effective in degrdading diazinon, however lower TOC removals were achieved. In case of photocatalysis, approximately 40% of nitrogen from diazinon was recovered as NO$_3^-$, and less than 5% of phosphorus as PO$_4{^{3-}}$. However, the sulfur in diazinon molecule was completely recovered to SO$_4{^{2-}}$ from photocatalysis reaction, and the recovery from photolysis was 50%, indicating that P=S bond easily breaks first during photolysis and photocatalysis. The poor recoveries of ionic byproducts and TOC from photolysis and photocatalysis indicate the presence of other organic intermediates during reactions. The formation of organic intermediates were identified during reactions using GC/MS and LC/MS/MS, and the main degradation products were diazoxon, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMP), respectively. Finally, the acute 48-hr toxicity test using Daphnia magna were employed to measure the toxicity reduction during photocatalysis of degradation. The results showed that the toxicity increased until 180 min of the photocatalysis reaction (from EC$_{50}$ (%) of 69.6 to 13.2%), however, acute toxicity completely disappeared (>100%) after 360 min. The toxicity results showed that the intermediates from photocatalysis such as diazoxon were more toxic than diazinon itself, however these intermediates can be degraded or mineralized with further reaction.