• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.108-121
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• 1994

The retention indices of branched-chain alkane, benzene ring, alcohol, amine, ketone, aldehyde and cyclic compounds were measured at 150, 180 and $210^{\circ}C$ on OV-1701 and OV-1 capillary columns. The group retention factors (GRF) of the substituents and the st` ructure retention factors (SRF) of the molecular structure change are derived from the retention indices of reference compounds and series of homologues. The $GRF_f$ equation of `f'th substituent is $GRF_f\;=\;I_{obs}-(100Z + \sum\limits_{i{\neq}f}GRF_i$ + {\sum}$SRF_i$)and the SRFf equation of `f'th molecular structure group is $SRF_f\;=\;I_{obs}-(100Z + {\sum}GRFi + \sum\limits_{i{\neq}f}SRF_i$). The predicted retention indices for those compound were in agreement, within the error of $\pm2$ and $\pm3%$, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively. The $\Delta$ xi of the substituents and $\Delta$ yi of the molecular structure change according to temperature change are derived from the $\Delta'/^{\circ}C$ of reference compounds and series of homologues. The $\Delta$ xi equation of the `f'th substituent is ${\Delta}x_f = {$\Delta}'/^{\circ}C+ \sum\limits_{i{\neq}f}\Delta$ xi + {\sum}{\Delta}yi\;and\;{\Delta}yi$ equation of the `f'th molecular structure group is ${\Delta}y_f$ = {\Delta}'/^{\circ}C+{\sum}{\Delta}xi +\sum\limits_{i{\neq}f}{\Delta}yi$. The predicted $\Delta'/^{\circ}C$ for these compounds were in agreement, within the error of ${\pm}18%$ and 17%, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.889-892
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• 2005

Standardized method based on extraction, filtration, and gas chromatography (GC) was developed far propylene glycol analysis to set hygienic norm of safety measure for foods under governmental control. Various columns were tested fur propylene glycol analysis by GC with flame ionization detector. Known amount of propylene glycol was spiked into wheat flour dough and analyzed by developed method. Results showed 101.60% recovery rate for propylene glycol with HP-5 column. Reproducibility test of standards recorded 0.30 for standard variation and 0,42% for relative variation. Using analytical method established, contents of propylene glycol in more than hundred different foods were monitored. Propylene glycol was detected in most foods, indicating propylene glycol is not only commonly added during food preparation, but also is contained naturally in food.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.292-302
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• 2005

Condition of Ion-Trap gas chromatography-mass spectrometry (GC-MS) for rapid screening of 206-pesticides residues in agricultural foodstuffs was optimized. As applying a wide-bore column (10 m${\times}$0.53 mm, DF 0.25 um) connected with a fused silica restrictor (0.6 m${\times}$0.1 mm), a significant retention time reduction was obtained. Additionally, the shape of peaks was sharper and higher than classical GC's and GC-MS's, which allowed lower detection limits. To easily manage many spectral data, both of Electron Ionization(EI) and Chemical Ionization(CI) techniques were adopted in screening procedure. At the following steps, MS-MS technique were used to confirm screened analytes in complicated matrices.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.277-283
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• 2005

A plasticizer is a substance which is added to a material to improve its processability, flexibility and stratchability. Phthalates and adipates are the most frequently used plasticizers of poly(vinyl chloride) (PVC). However, they can migtate into food from PVC food packaging, and some of them are especially suspected as endocrine disruptors. In this study, Simultaneous analysis of 13 phthalates and 9 adipates were carried out by dual-column gas chromatography system equipped wi two FID detectors for rapid confirmation and quantification. The Proposed method was validated with > 0.993 of linearity in the ranges of 10-500 mg/l, < $3.5\%$ RSD of reproducability in 10 inter-days sample preparations, and > $98.1\%$ of recoveries for all the plasticizers. DEHA was detected in all the 3 PVC wraps at levels of 176.9-198.5mg/g. Among the 51 samples of PVC gaskets, the targeted plasticizers were detected in 41 samples. Of these plasticizer detected samples,40 contained DIDP at the levels of 157.3-374.7 mg/g and one contained DMP at the levels of 165.6 mg/g. Also, some plasticizers were detected in other packaging materials such as PET, PP, PE, Pulp. But it might be attributed to contamination in manufacturing.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.149-154
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• 1998

The authors attempted utilization of fatty acid composition of vibrios as a tool for identification of the strains. Fatty acid of 49 strains of Vibrio cholerae non-O1, V. cholerae O1, V mimicus, V vulinificus and V parahaemolyticus was analyzed by gas-liquid chromatography column. According to the statistical analysis of the fatty acid data, the relationship between the Vibrio species and serotypes of the strains was discussed. Forty one kinds of fatty acid were detected from the tested strains and 35 kinds of fatty acids among the detected fatty acids were significant factors to identify the vibrios. The predominant fatty acids were 16:0, 16:1 cis 9, 18:1 trans 9/6/cis 11 and 15:0 iso 2OH/16:1 cis 9 as above about 20% in total. Fatty acid compositions of the Vibrio species were an important factor in identifying their subspecies either predominant fatty acids or minor ones. According to the analysed results by a conventional statistical processing method (UPGMA) and prepared dendrogram, V cholerae non-01 had more closer relationship with V. mimicus compared with V. cholerae 01. Moreover, the distribution of hydroxy acid was a significant factor for identifying V cholerae subspecies. Comprising all the 10 serotypes detected from V. cholerae non-01 examined such as O2, O5, O8, O10, O14, O27, O37, O39, O45 and O69, we could group them into seven subspecies by cluster analysis with the similarity value of fatty acid composition as above 92%. It means that there is a significant relationship between serotypes and fatty acid composition of V. cholerae. These results indicated that numerical analysis of fatty acid composition data of V cholerae non-01 could classifY them into subspecies, and also which may provide a useful epidemiologic information or a basis for further analysis such as PCR and DNA probe analysis.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.133-148
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• 1987

Gibberellin(GA) 3-$\beta$ hydroxylation is very important for the shoot elogation in the higher plants, since only 3$\beta$-hydryoxylated GAs promote shoot elogation in several plants. Fluctuation of 3$\beta$-hydryoxylase activity was examined during seed maturation using two cultivars of , P. vulgaris, Kentucky Wonder (normal) and Masterpiece (dwarf). Very immature seeds of both cultivars contain high level of 3$\beta$-hydroxylase activity (per mg protein). Both cultivars showed maximum of enzyme activity (per seed) in the middle of their maturation process. Gibberellin 3$\beta$-hydroxylase catalyzing the hydroxylation of GA20 to GA1 was purified 313-fold from very early immature seeds of P. vulgaris. Crude soluble enzyme extracts were purified by 15% methanol precipitation, hydrophobic interaction chromatogrphy, DEAE ion exchange column chromatography and gel filtration HPLC. The 3$\beta$-hydroxylase activity was unstable and lost much of its activity duting the purification. The molecular weight of purified enzyme was extimated to be 42, 000 by gel filtration HPLC and SDS-PAGE. The enzyme exhibited maximum activity at pH 7.7. The Km values for [2.3-3H] GA20 and [2.3-3H]GA9 were 0.29 $\mu$M and 0.33 $\mu$M, respectively. The enzyme requires 2-oxoglutarate as a cosubstrate; the Km value for 2-oxoglutarate was 250 $\mu$M using 3H GA20 as a substrate. Fe2+ and ascorbate significantly activated the enzyme at all purification steps, while catalase and BSA activated the purified enzyme only. The enzyme was inhibited by divalent cations Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+. Effects of several GAs and GA anaogues on the putrified 3$\beta$-hydroxylase were examined using [3H]GA9 and GA20 as a substrates. Among them, GA5, GA9, GA15, GA20 and GA44 inhibited the enzyme activity. [13C, 3H] GA20 was converted by the partially purified enzyme preparation to [13C, 3H]GA1, GA5 and GA6, which were identified by GC-MS, GA9 was converted only GA4, GA15 and GA44 were converted to GA37 and GA38, respectively. GA5 was epoxidized to GA6 by the preparation. This suggests that 3$\beta$-hydroxylation of GA20 and epoxidation of GA5 are catalyzed by the same enzyme in P, vulgaris.

• Analytical Science and Technology
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• v.16 no.1
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• pp.70-77
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• 2003

The optimum conditions for the residue analysis of hydroxyanilide fungicide fenhexamid on cucumber, strawberry and grape were investigated by gas chromatography equipped with electron capture detector (GC-ECD) and the residual amount was determined by sprayed days before harvest. Each samples were extracted with acetone, filtered and concentrated to 50 mL. The concentrated extracts were transferred to dichloromethane and then thoroughly concentrated. The concentrated phase was loaded on the filtration column stuffed with silica gel and purified with acetone:hexane (5:95, 15:85, v/v) mixed solvent. The regression equation and linearity of the standard calibration curves between 0.05~2.00 ng were as follows : cucumber; Y=312.40X+10.26, $R^2=0.9996$, strawberry; Y=313.33X+5.54, $R^2=0.9998$, grape; Y=253.27X-2.23, $R^2=0.9994$. From the standard additional experiments with 0.10 mg/L and 0.40 mg/L, the average recoveries of cucumber, strawberry and grape were 94.8%, 88.1% and 93.7%, respectively and the detection limits were all the same as 0.01 mg/L. Residual amounts in crops were ranged from 0.01 to 0.58 mg/L.

• 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.

• 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.45 no.1
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• pp.20-24
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• 2013

Food irradiation has recently become one of the most successful techniques to preserve food with increased shelf life. This study aims to analyze hydrocarbons in almonds (Prunus amygosalus L.) and peanuts (Arachis hypogaea) induced by electron beam irradiation. The samples were irradiated at 0, 1, 3, 5 and 10 kGy by e-beam and using florisil column chromatography fat, and content was extracted. The induced hydrocarbons were identified using gas chromatography-mass spectrometry (GC/MS). The major hydrocarbons in both irradiated samples were 1,7-hexadecadiene ($C_{16:2}$) and 8-heptadecene ($C_{17:1}$) from oleic acid, 1,7,10-hexadecatriene ($C_{16:3}$) and 6,9-heptadecadiene ($C_{17:2}$) from linoleic acid and 1-tetradecene ($C_{14:1}$) and pentadecane ($C_{15:0}$) from palmitic acid. Concentrations of the hydrocarbons produced by e-beam were found to be depended upon the composition of fatty acid in both almonds and peanuts. The $C_{n-2}$ compound was found to be higher than $C_{n-1}$ compound in oleic acid and palmitic acid, while in case of linoleic acid, $C_{n-1}$compound was higher than $C_{n-2}$ compound. The radiation induced hydrocarbons were detected only in irradiated samples, with 1 kGy or above, and not in the non-irradiated ones. The production of 1,7-hexadecadiene ($C_{16:2}$), 8-heptadecene ($C_{17:1}$), 1,7,10-hexadecatriene ($C_{16:3}$) and 6,9-heptadecadiene ($C_{17:2}$), in high concentration gave enough information to suggest that these may be the possible marker compounds of electron beam irradiation in almonds and peanuts.