• 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.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.283-292
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• 2013

A series of monitoring studies were carried out to evaluate the residue level of pesticides in different native soils from 1999 to 2006. The nation-wide collection of soil samples from paddy, greenhouse, upland and orchard, were analyzed by GLC (ECD or NPD) and GC/MS. The results obtained are summarized as follows; out of 14 pesticides detected from paddy soils in 1999, the highest residue level was 0.25 mg $kg^{-1}$, and the frequency was 21.7% as butachlor, 20.0% as isoprothiolane, and 16.7% as iprobenfos. In 2003, 7 pesticides were detected and their frequencies were 0~36.0%; the frequency was 36.0% as isoprothiolane and 33.3% as oxadiazon. In the year 2000, 57 pesticides in the greenhouse soil samples were detected with the highest frequency of 65.3%. Of the pesticides detected, endosulfan and procymidone showed the frequency of 65.3 and 50.0%, respectively. In 2004, 19 pesticides were detected from greenhouse soils, and their frequencies and residue levels were decreased. Endosulfan and procymidone showed high detection frequencies and concentrations of 21.3 and 9.3% and 0.76 and 0.31 mg $kg^{-1}$, respectively. In 2001, a total of 25 pesticides were detected through monitoring in 170 upland soils and the highest residue level was 2.24 mg $kg^{-1}$. The detection frequencies showed the range of 0~53.5%. Especially, endosulfan showed the highest frequency of 53.5%. Residue levels and frequencies of pesticide in the year 2005 were almost the same compared with that of the year 2001. As a result of monitoring in 150 orchard soils in 2002, 26 pesticides were detected and the highest residue level was 1.43 mg $kg^{-1}$. Of them, the frequency of endosulfan showed the highest as 45.3%. In 2006, 20 pesticides were detected in orchard soils. The frequency of total endosulfan was the highest as 5.3% but was lower than that of the year 2002.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.104-116
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• 2018

BACKGROUND: This experiment was conducted to establish a simultaneous analysis method for 7 kinds of herbicides in 3 different classes having similar physicochemical property as diphenyl ether(bifenox and oxyfluorfen), dinitroaniline (ethalfluralin and trifluralin), and chloroacetamide (metolachlor, pretilachlor, and thenylchlor) in crops using GC-ECD/MS. METHODS AND RESULTS: All the 7 pesticide residues were extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and directly partitioned into n-hexane/dichloromethane(80/20, v/v) to remove polar co-extractives in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. The analytes were separated and quantitated by GLC with ECD using a DB-1 capillary column. Accuracy and precision of the proposed method was validated by the recovery experiment on every crop samples fortified with bifenox, ethalfluralin, metolachlor, oxyfluorfen, pretilachlor, thenylchlor, and trifluralin at 3 concentration levels per crop in each triplication. CONCLUSION: Mean recoveries of the 7 pesticide residues ranged from 75.7 to 114.8% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of the analytes were 0.004 (etahlfluralin and trifluralin), 0.008 (metolachlor and pretilachlor), 0.006 (thenylchlor), 0.002 (oxyfluorfen), and 0.02 (bifenox) mg/kg as verified by the recovery experiment. A confirmatory technique using GC/MS with selected-ion monitoring was also provided to clearly identify the suspected residues. Therefore, this analytical method was reproducible and sensitive enough to determine the residues of bifenox, ethalfluralin, metolachlor, oxyfluorfen, pretilachlor, thenylchlor, and trifluralin in agricultural commodities.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.71-80
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• 1978

In an attempt to elucidate the fate of 3,4-DCA and TCAB in various French soils, uniformly $^{14}C-ring-labeled$ 3,4-DCA and TCAB mere utilized and the following results obtained. 1) The rate of breakdown of $^{14}C-3,4-DCA$ into $^{14}CO_2$ was relatively higher in the early stage than that in the later stage. In 6 months of incubation in alkaline soil (pH 7.9), the rate was as high as 6.5% at dose 1 (1.5 ppm) and as low as 1.92% at dose 2(94 ppm), whereas in organic acid soil (pH 5.5) the rate was 4.91% at dose 1 and 4.24% at dose 2, respectively, without making any great difference between the two levels. 2) At dose 1, 47.70% of the initial radioactivity of $^{14}C-3,4-DCA$ was bound to soil in organic acid soil and 29.49% bound in alkaline soil, whereas at dose 2, 38.40% in organic acid soil and 20.30% in alkaline soil, respectively. 3) The amount of formation of $^{14}C-TCAB$ from $^{14}C-3,4-DCA$ seems to depend largely on the concentration of 3,4-DCA applied rather than on soil types. At dose 2, the amount was 50% of the total radioactivity extracted in organic acid soil and 30% in alkaline soil, corresponding to 1.8% and 1.4% of the initial radioactivity applied to soil, respectively. Cis-TCAB also seemed to be formed at dose 2 in both soils. Meanwhile, at dose 1, even though $^{14}C-TCAB$ was detected in trace on tlc and glc in both soils, the amount does not exceed 2 to 3% of the radioactivity extracted, corresponding to 0.05 to 0.1% of the initial radioactivity. 4) The rate of breakdown of $^{14}C-TCAB$ into $^{14}CO_2$ ranged from 0.05 to 0.20% in all the four soils. Most of the applied $^{14}C-TCAB$ remained intact after 3 months, not producing any detectable metabolites. 5) The fact that much more $^{14}C-TCAB$ was adsorbed to alkaline soil than to the other soils strongly indicates that in alkaline condition trans-isomer was converted tocisisomer which has the higher adsorption affinity than the former.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.381-393
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• 2010

In order to monitor the residual characteristics of the pesticides in leafy vegetables selling at wholesale markets and traditional markets in Cheongju, a total of 180 samples of 15 leafy vegetables, such as broccoli, celery, chard, chicory, Chinese vegetable, Chwinamul, crown daisy, Korean cabbage, leek, lettuce, perilla leaves, Shinsuncho, spinach, welsh onion and young radish, were purchased from the wholesale markets and traditional markets in June and August in 2010 and the pesticide residues in them were analyzed by multiresidue analysis method using GLC, HPLC and GC-MSD. Seven pesticides were detected from 12 samples out of total 180 samples collected, representing detection rate was 6.7%. In case of the samples collected from markets in June, four pesticides including tefluthrin were detected from six samples and in case of the samples collected from markets in August, three pesticides including pendimethalin were detected from three samples. The MRL-exceeding rate of pesticides detected from leafy vegetables was 0.6%. The pesticide exceeded its MRL was azoxystrobin detected from crown daisy and many pesticides were not registered to the crops, excepting that azoxystrobin detected from Chwinamul and tefluthrin from leek. Estimated daily intakes (EDIs) of the pesticides detected from leafy vegetables were less than 7% of their acceptable daily intakes (ADIs), representing that residue levels of the pesticides detected were evaluated as safe.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.321-326
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• 1986

Oyster (Crassostrea gigas), arkshell (Anadare(Scapharce) broughtonii) and sea-mussel (Mytilus edulis) were investigated as to their lipid classes. Lipid extracts from shellfishes were fractionated into neutral lipid (NL), glycolipid (GL) and phospho-lipid (PL) by column chromatography with silicic acid. The fatty acid compositions of their lipid classes and lipid fractions were determined by gas liquid chromatography (GLC). Total lipid contents of shellfishes were $3.5\%$ in the oyster, $1.4\%$ in the arkshell, $1.0\%$ in the sea-mussel. The major fatty acids of total lipids were palmitic acid, eicosapentaenoic acid and docosahexaenoic acid in the oyster and the sea-mussel, palmitic acid, oleic acid and eicosapentaenoic acid in the arkshell. The lipid composition of neutral lipid fractions in shellfishes was separated and identified as free sterol, free fatty acid, triglyceride, hydrocarbon and esterified sterol by TLC. Of these classes, triglyceride fraction was most abundant, amounting to 55.6, 77.7 and $60.4\%$ in the three samples mentioned above, respectively. The main fatty acids of glycolipid were palmitic acid, eicosaenoic acid and docosahexaenoic acid in oyster, myristic acid, palmitic acid and palmitoleic acid in the arkshell, docosahexaenoic acid, linolenic acid and palmitic acid in the sea-mussel. The major fatty acids of phospholipid were palmitic acid, eicosapentaenoic acid and docosahexaenoic acid in the oyster and sea-mussel, palmitic acid, eicosapentaenoic acid and erucic acid in the arkshell.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.417-423
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• 1985

In succession to the previous paper, the present study was directed to investigate the nonvolatile organic acids composition in raw and belied-dried products of oyster, sea-mussel, baby clam and hen clam by gas liquid chromatography. The results obtained are summarized as follows : In four kinds of the samples examined, eight kinds of organic acids were identified and determined in oyster, sea-mussel and baby clam, and nine kinds in hen clam. The major organic acids in oyster were pyroglutamic, succinic and malic acid which was $94.2\%$ of total quantity of organic acid, and those in sea-mussel, baby clam and hen clam were succinic and malic acid which were $90.8\%,\;89.7\%\;and\;86.4\%$ of total acids, respectively. The most abundant organic acid in sea-mussel, baby clam and hen clam was succinic acid that was $80.6\%,\;84.9\%\;and\;73.2\%$ in total acids, repectively. And that of oyster was pyroglutamic acid which marked $38.8\%$ in total acids, and the next one was succinc acid marked $34.4\%$. In the total quantity of organic acid, the highest was 913.0 mg/100g in oyster which showed 4.5 times as much as in hen clam, followed by 478.4 mg/100g in sea-mussel, 246.3mg/100g in baby clam, and the least was 201.2 mg/100g in hen clam. The decreasing rate of total quently of organic acids by boiled-dried procersing was the highest in oyster, $54.7\%$, followed by $46.5\%$ in sea-mussel, $37.1\%$ in hen clam and $29.4\%$ in baby clam. The decreasing rate of each organic acid shelved much difference according to the samples examined, in general, great in malic, fumaric and proglutamic acid ana less in succinic, lactic and oxalic acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.519-528
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• 1985

Fillets of mackerel (Scomber japonicus) and flounder (Xystrias grigorjewi) which, are representatives in red fleshed fish and white fleshed fish, respectively, were freeze-dried and stored in tightly sealed containers which were controlled to different relative humidity at $25^{\circ}C$. The changes of lipids were examined periodically by measuring the peroxide value (POV), the thiobarbituric acid (TBA) and the acid value (AV). And the fatty acid composition of lipids was investigated by gas-liquid chromatography (GLC). The results obtained are summarized as foollows: From the changes of POV and TBA value during storage, the oxidation of lipids was distinct at the lower relative humidities, $0\%\;and\;23\%$, while inhibited at the higher relative humidities, $52\%\;and\;81\%$. The changes in acid value during storage were more prominent at the hifger relative himidites than at the lower relative humidities. The content of $C_{16:0},\;C_{18:0}\;and\;C_{22:6}$ acids in the fatty acid composition of total lipids was abundant in both fleshed fishes. The content of $C_{18:1}$ acid in the nonpolar lipid and that of $C_{16:0}$ acid in the polar lipid were higher than other fatty acids. In the fatty acid composition of total lipids during storage, polyenoic acids decreased with storage period at $0\%\;and\;23\%$ relative humidities, while the fatty acid composition didn't show a great change at $52\%\;and\;81\%$ relative humidities. In the non-polar lipid, polyenoic acids coherently decreased under all the conditions of relative humidities but the saturated acids and the monoenoic acids increased. In the polar lipid, polyenoic acids decreased at $0\%\;and\;23\%$ relative humidities, while the saturated acids and monoenoic acids decreased at $52\%\;and\;81\%$ relative humidities. On the other hand, the oxidation of lipids was more significant in mackerel than in the flounder, and the changes of fatty acid composition were shown a similar pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.433-438
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• 1985

Lipids extracted from two kinds of sun-dried laver samples, wild Porphyra suborbiculata and cultured Porphyra tenera, produced at Wan-do in Korea were studied. Dried P. suborbiculata contained $0.8\%$ total lipid(TL) which consisted of $21.4\%$ neutral lipid(NL), $53.4\%$ glycolipid(GL) and $25.2\%$ phospholipid(PL), and dried P. tenera contained $1.2\%$ TL which consisted of $30.5\%$ NL, $50.3\%$ GL and $19.2\%$ PL. Among the NL of dried P. suborbiculate and P. tenera, free fatty acid ($41.4\%,\;39.0\%$), triglyceride($25.6\%,\;28.8\%$) and free sterol ($22.1\%,\;16.7\%$) were predominant. Digalactosyl diglyceride ($34.7\%,\;46.6\%$) and monogalactosyl diglyceride ($19.2\%,\;18.0\%$) were the major components among the GL. Sulfoquinovosyl digylceride ($4.2\%$) was also identified in P. tenera only. And main lipids in the PL of P. suborbiculata and P. tenera were phosphatidyl ethanolamine ($40.3\%,\;35.7\%$) and phosphatidyl choline ($28.6\%,\;30.7\%$) and followed by phosphatidyl serine($15.1\%,\;19.2\%$) and phosphatidyl inositol ($16.0\%,\;14.4\%$). The major fatty acids in the TL of the dried P. suborbiculata were 20:5 ($29.4\%$), 16:0 ($23.4\%$) and 20:4 ($13.0\%$), and those of the dried P. tenera were 20:5 ($36.7\%$), 16:0 ($16.2\%$), 16:1 ($10.7\%$) and 18:1 ($9.7\%$). The fatty acid composition of the both samples in the NL fraction were similar to the pattern in those of the TL. The abundant fatty acids in the PL of the both dried laver were 20:5, 16:0 and 18:1. In case of the GL fraction, the main fatty acids of the dried P. suborbiculata were 16:0, 20:5, 18:1 and 20:4, while those of the dried P. tenera were 20:5, 16:0 and 18:1.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.227-233
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• 1986

The compositions and seasonal variations of free sugars and non-volatile organic acids of brown algae, such as Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides were investigated by gas chromatography. Four kinds of free sugars, such as xylose, glucose, galactose and floridoside were identified. The most abundant one was floridoside marking 118.7 mg/100 g, 90.9 mg/100 g and 70.0 mg/100 g in Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinguishable seasonal variations in the contents of free sugars in all the samples. In the case of organic acids, nine kinds were identified in Ecklenia cava and major ones were succinic, citric, malic, fumaric, oxalic and lactic acid, of which succinic acid was the most abundant one marking $30.6\%$ of total organic acids. In Sargassum ringgoldianum and Myagropsis myagroides, eight kinds were identified, which major ones were succinic, citric and malic acid in both samples, and they marked $68.4\%$ and $61.1\%$ of total organic acids in Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinct changes in the content of total organic acids according to seasons in all the samples examined. The contents of total organic acics in Ecklonia cava was a little more than Sargassnm ringgoldianum and Myagropsis myagroides.