• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1042-1049
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• 2000

Irradiation-induced volatile flavor compounds in irradiated (1, 3, 5, 10 kGy) beef were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred fifty volatile compounds were detected in irradiated beef. These compounds were composed mainly of 71 hydrocarbons, 35 aromatic compounds, 15 aldehydes, 7 ketones, 4 acids, 6 esters and 12 miscellaneous compounds. Among these, only 6 volatile compounds including (E) -2-hexenal, nonene, 2-nonenal, cyclodecene, dodecene and cyclododecene were detected as irradiation-induced volatile flavor compounds, comparing with unirradiated beef meat. However, 4 volatile compounds, such as cyclodecene (r=0.88), (E)-2-hexenal (r=0.85), nonene (r=0.74) and 2-nonenal (r=0.70), having a positive correlation coefficient with the increment of irradiation dose, were considered as marker compounds for detecting irradiation dosages in irradiated beef.

• Analytical Science and Technology
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• v.24 no.1
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• pp.1-9
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• 2011

We described an estimation of measurement uncertainty in quantitative analysis of 11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THC-COOH), the metabolite of ${\Delta}^9$-tetrahydrocannabinol, in hair samples by using the bead-assisted liquid-liquid extraction and gas chromatography-tandem mass spectrometric (GC-NCI-MS/MS) detection. Traceability of measurement was established through the use of reference materials, calibrated volumetric tubes, volume measuring devices, and measuring instruments. The analytical results were compared and the different contributions to the uncertainty were evaluated. Inter-day variation was performed by using statistical analysis of several indicative factors. Measurement uncertainty associated with the analyte in real forensic hair samples were estimated using QC data. The major factor of contribution to combined standard uncertainty was inter-day repeatability, while those associated with preparation of analytical standard and also sample of weight were insignificant considering the degree of contribution. Relative uncertainty of relative extended standard uncertainty divided into the measured concentration of the analyte was 17% in a hair sample. The uncertainty of result evaluation will be invaluable to improve quality of the analysis.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.134-141
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• 2021

BACKGROUND: The analytical method was established for determination of fungicide chinomethionat in several animal commodities using gas chromatography (GC) coupled with electron capture detector (ECD). METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining chinomethonat in various livestock products including beef, pork, chicken, milk and egg. Chinomethionat residual was extracted using acetone/dichloromethane(9/1, v/v) with magnesium sulfate and sodium chloride (salting outassociated liquid-liquid extraction). The extract was diluted by direct partitioning into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was finally purified with optimized silica gel 10 g. CONCLUSION: The method limit of quantitation (MLOQ) was 0.02 mg/kg, which was in accordance with the maximum residue level (MRL) of chinomathionate as 0.05 mg/kg in livestock product. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (84.8~103.0%). Reproducibilities were obtained (Coefficient of variation <5.2%), and the linearity of calibration curves were reasonable (r²>0.995) in the range of 0.01-0.2 ㎍/mL. This established analytical method was fully validated and could be useful for quantification of chinomathionat in animal commodities as official analytical method.

• Analytical Science and Technology
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• v.21 no.6
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• pp.459-473
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• 2008

Antifouling agents including tributyltin (TBT) compound and its derivatives have been used for many years, but the usage of TBT in Korea was legally restricted in 2003, due to its significant environmental impact. Following this, many new alternative antifouling agents have been used. In this experiment, four major antifouling agents were selectively analyzed to study their release in seawater and tidal flats on the Korean Peninsula. These new antifouling agents were extracted from the seawater and tidal flats using a liquid-liquid extraction method and microwave extraction, respectively. The measured concentrations of Irgarol 1051, Sea-Nine 211, Dichlofluanid and Chlorothalonil ranged from N.D.$-23.80ng/{\ell}$, N.D.$-15.30ng/{\ell}$, N.D.$-61.69ng/{\ell}$ and N.D.$-4.19ng/{\ell}$ in the seawater samples and from N.D.-159.45 ng/g, N.D.-476.57 ng/g, N.D.-59.79 ng/g and N.D.-21.27 ng/g in the tidal flat samples, respectively. Interestingly, these new antifouling agents were not detected in any area in the tidal flats at Pusan, whereas a certain amount of them was found in the seawater.

• Analytical Science and Technology
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• v.21 no.4
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• pp.259-271
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• 2008

The analytical method of extracting compounds from human blood to examine accumulated organochlorine pesticides (OCPs) has been widely used the traditional liquid-liquid extraction (LLE) method and solid-phase extraction (SPE) method, yet these methods have certain limitations in purification and usafe of a large amount of sample. In order to overcome the se problems reside in these, solid-phase microextraction (SPME), known as a highly efficient extration method with less samples and relatively simple, was employed to collect 18 different kinds of OCPs in blood as extraction method in this study. To optimize extraction method, we examine various experimental SPME-parameters such as adsorption (fiber type, adsorption time, adsorption temperature, salting out effect), and desorption (desorption time, desorption temperature etc.). From the experimental results, the optimal conditions are as follows: fiber was polyacrylate with $85{\mu}m$, adsorption time was for 5 min, adsorption optimum temperature was at $280^{\circ}C$, and salting out effect was NaCl with 0.1 g. MDL, precision and accuracy was in the ranges of 0.05~0.20 ng/mL, 5.59~13.39%, respedively, and accuracy was -0.5% ~24.5% for all OCPs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.333-343
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• 1984

This study was designed to elucidate the lipid and its fatty acid composition in various tissues of fresh water fishes. The free and bound lipids in meat, skin and viscera of crucian carp (Carassius carassius) were extracted with ethyl ether and the mixed solvent of chloroform-methanol-water (10/9/1, v/v). The free and bound lipids were fractionated into neutral lipid, glycolipid and phospholipid by a silicic acid column chromatography using chloroform, acetone and methanol, respectively, and quantitatively analyzed by thin layer chromatography (TLC) and TLC scanner. The fatty acid compositions of polar ana nonpolar lipids in meat, and these of neutral lipid in various tissues were analyzed by gas liquid chromatography(GLC). The free lipid content in meat, skin and viscera was $6.22\%,\;9.95\%\;and\;9.76\%$, whereas the bound lipid content in those tissues was $10.01\%,\;3.56\%\;and\;7.36\%$, respectively. The neutral lipid contents in free lipid were ranged from $71.7\%$ to $89.4\%$, and $3{\sim}9$ times higher than those in bound lipid, while the phospholipid contents in bound lipid were ranged from $42.3\%$ to $63.2\%$, and $5{\sim}10$ times higher than those in free lipid. The neutral lipid was mainly consisted of triglyceride ($81.91{\sim}88.34\%$) in free lipid, and esterified sterol & hydrocarbon ($41.00{\sim}59.43\%$) in bound lipid. The phospholipid was mainly consisted of phosphatidyl ethanolamine($54.56{\sim}66.79\%$) and phosphatidyl choline ($21.88{\sim}34.28\%$) in free lipid, and phosphatidyl choline ($50.49{\sim}70.57\%$) and phosphatidyl ethanolamine ($15.74{\sim}24.92\%$) in bound lipid. The major fatty acids of polar lipid in free and bound lipids were $C_{16:0}\;(17.53\%,\;19.29\%)$, $C_{18:1}\;(24.57\%,\;16.08\%)$, $C_{18:2}\;(8.39\%,\;4.03\%)$, $C_{22:5}\;(1.68\%,\;8.08\%)$, and $C_{22:6}\;(6.22\%,\;13.60\%)$ and these of neutral lipid in free and bound lipids were $C_{16:0}\;(17.67\%,\;24.15\%)$, $C_{16:1}\;(12.81\%,\;5.52\%)$, $C_{18:1}\;(24.13\%,\;13.02\%)$, $C_{18:2}\;(15.47\%,\;8.68\%)$, $C_{22:5}\;(0.88\%,\;4.14\%)$ and $C_{22:6}\;(1.17\%,\;5.04\%)$, respectively. The unsaturations (TUFA/TSFA) of polar lipid in free and bound lipids were 2.02 and 2.74, and $1.5{\sim}2.0$ times higher than 1.51 and 1.23 of nonpolar lipid. In both polar and nonpolar lipids, w3 highly unsaturated fatty acid (w3HUFA) content of bound lipid was $2{\sim}5$ times higher than that of free lipid. The polyenoic acid contents such as $C_{20:5},\;C_{22:5}\;and\;C_{22:6}$ in bound lipid were $2{\sim}5$ times higher than these in free lipid. Consequently, there were significant difference between the lipid and its fatty acid composition in free and bound lipids and/or in various tissues.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.36-43
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• 2011

Plant biomass has been proposed as an alternative source of petroleum-based chemical compounds. Especially, aromatic chemical compounds can be obtained from lignin by depolymerization processes because the lignin consist of complex aromatic materials. In this study, kraft lignin, the largest emitted substance among several kinds of lignin in Korea, was used as a starting material and was characterized by solid-state $^{13}C$-Muclear Magnetic Resonance($^{13}C$-NMR), Fourier Transform Infrared Spectroscopy(FT-IR), Elemental Analysis(EA). The depolymerization of kraft lignin was studied at water-phenol mixture solvent in near critical region and the experiments were conducted using a batch type reactor. The effects of water-to-phenol ratio and reaction temperature($300-400^{\circ}C$) were investigated to determine the optimum operating conditions. Additionally, the effects of formic acid as a hydrogen-donor solvent instead of $H_2$ gas were examined. The chemical species and quantities in the liquid products were analyzed using gas chromatography-mass spectroscopy(GC-MS), and solid residues(char) were analyzed using FT-IR. GC-MS analysis confirmed that the aromatic chemicals such as anisole, o-cresol(2-methylphenol), p-cresol(4-methylphenol), 2-ethylphenol, 4-ethylphenol, dibenzofuran, 3-methyl cabazole and xanthene were produced when phenol was added in the water as a co-solvent.

• The Korean Journal of Mycology
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• v.35 no.2
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• pp.96-100
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• 2007

In order to select ${\gamma}-Linolenic$ acid (GLA)-producing fungi, a total of forty-four strains of 4 genera such as Phytophthora, Pythium, Mucor and Rhizopus were obtained from Koran Agricultural Culture Collection (KACC) and then analysed by using GC-FID and GC-MS. GLA was detected on 39 fungal strains, and the highest rate of GLA was found as 24.8% of total fatty acids on Mucor hiemalis f. sp. hiemalis KACC 40264. Total GLA content of Zygomycota was comparatively high - Mucor (14.2%) and Rhizopus (14.3%), whereas that of Oomycetes was low - Phytophthora (3.3%) and Pythium (3.0%). Moreover, total fatty acids of the Zygomycota fungi such as Mucor (15.4 mg/100 ml) and Rhizopus (7.1 mg/100 ml) were higher compared with the Oomycetes such as Phytophthora (2.6 mg/100 ml) and Pythium (4.5 mg/100 ml). Thus, two genera such as Mucor and Rhizopus have higher potential as an useful microbial resource. The total fatty acid content varies even within the strains of the same genus e.g. Mucor. M. blumbeus KACC 40935 showed the highest values on productivity (18.2%) of GLA and total fatty acid contents (50.8 mg/100 ml liquid medium).

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.97-105
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• 1982

The edible portion of chestnut, Castenea crenata Sieb, et Zucc, were freeze-dried and subjected to analysis of minerals, lipid classes and fatty acid composition by silicic acid column chromatography and gas-liquid chromatography. The results of analysis for the minerals in chestnut showed that the contents of magnesium, iron and phosphorus were decreased during storage after freeze-drying. The contents of neutral lipids, glycolipids and phospholipids in the raw edible portion were 34.6, 38.6, and 26.8%, respectively. The contents of neutral lipids and phospholipids of the freeze-dried chestnut were decreased, while glycolipids were increased during storage. In the fatty acid composition of total lipid, $C_{16:0}$, $C_{18:2}$ and $C_{18:3}$ acid were abundant in the raw edible portion, but freeze-dried chestnut contained relatively much amount of $C_{16:0}$, $C_{18:1}$, and $C_{18:2}$ acid. It is noticeable that $C_{18:2}$ and $C_{18:3}$ acid in the freeze-dried chestnut were remarkably decreased during storage. Upon the fatty acid composition, total lipid contained $C_{18:2}$ and $C_{16:0}$ acid in the highest proportion, but neutral lipids, glycolipids and phospholipids contained $C_{16:0}$ and $C_{18:2}$ acid in the highest proportion. Cycloartenol (20.6%) was a major component in the 4-monomethylsterol fraction separated by thin layer chromatography and cyclolaudenol, cycloeucalenol, and citrostadienol were detected as minor components. Sitosterol (74.6%) was a major component in the 4-desmethylsterol fraction separated by thin-layer chromatography and ${\Delta}^5-avensterol$, campesterol, stigmasterol and brassicasterol were also detected as minor components.

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.674-682
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• 1988

Total lipids from the roe, muscle and viscus of L. carinata were analyzed for lipid composition by column chromatography, thin-layer chromatography and gas-liquid chromatography. The roe lipids were characterized by a high level of wax esters (63.1%) and a low proportion of trigiycerides (9.9%). The viscus lipids also contained wax esters (32.8%) as its main component, followed by free fatty alcohols and acids (23.5%). On the other hand, the muscle lipids were found to contain a large amount of triglycerides (66.1%) with a trace of wax esters. The main fatty alcohol component of roe and viscus wax esters was C16:0 alcohol (53.0%; 61.7%), accompanied by C18:1 alcohol (10.2%) in the former and by C15:0 alcohol (8.8%) in the latter. Considerable amounts of odd-numbered fatty alcohols were found in both wax esters. On the other hand, the fatty acids of the roe and viscus wax esters contained a high percentage of monounsaturated (49.7%-56.6%) consisting of C16:1, C18:1 and C17:1 acid, and a significant amount of polyunsaturated (41.2%-32.9%), particularly C20:5${\omega}$3. The fatty acid components of triglycerides and phospholipids were different among the tissues tested, especially between roe and muscle or viscus. The fatty acid compositions of free fatty acids from the muscle and viscus were characterized by a higher level of polyunsaturated fatty acids (46.0-34.3%) compared to those of triglycerides 'in the roe, muscle and viscus (28.4%, 19.4% and 19.2%).