• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.958-964
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• 2002

To select the irradiation-induced marker components from volatile flavor compounds in irradiated chicken, and complement the extraction problems of liquid continuous extraction (LLCE) method, the volatile compounds of irradiated (0,1,3,5 and 10 kGy) chicken were analyzed by Purge and Trap (P&T) and gas chromatography/mass spectrometry (GC/MS) methods. A total of 119 compounds were detected in irradiated chicken, and these compounds were composed mainly of 7 aldehydes,22 ketones,8 alcohols,30 esters,36 hydrocarbons,8 aromatic compounds and 8 miscellaneous compounds. Among these, only 21 compounds were detected in both LLCE and P&T methods, and the 98 other were detected in omly P&T method. Among volatile compounds detected in irradiated chicken, only 3 compounds such as hexene (r=0.96, p<0.01), propanol (r=0.93, p<0.05) and 1,3-bis(1,1-dimethylethyl) benzene (r=0.96, p<0.05) were newly selected as marker compounds in irradiated chicken by P&T method, which showed significant and high positive correlation coefficient in the change of relative concentration according to the increment of irradiation dosage.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.326-331
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• 2006

In the present study, we examined biosorption characteristics of heavy metals onto the extracellular polysaccharide (EPS) produced by the purple nonsulfur photosynthetic bacteria Rhodopseudomonas sp. KH4, which was isolated from a stream in Anyang, Kyonggi-Do. When Cd (100 mg/L) and Cu (100 mg/L) were added to EPS (1.0 g/L) in the optimal condition (Cd; pH 8, Cu; pH 5, $40^{\circ}C$), 84.2 mg/L of Cd and 70.0 mg/L of Cu were adsorbed within 30 min and 10 min, respectively. When 100 mg/L of Cd and Cu were present as mixture, 16.8 mg/L of Cd and 48.7 mg/L of Cu were adsorbed at $25^{\circ}C$, pH 5. The maximum adsorption capacity determined by fitting Langmuir isotherms model was suitable for describing the biosorption of Cd (76.9 mg/g) and Cu (67.1 mg/g) by EPS. The neutral monosaccharide in the EPS determined by GC consisted of arabinose (2.4%), glucose (7.1%) and mannose (90.5%).

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.269-278
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• 2017

BACKGROUND: The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds. METHODS AND RESULTS: Extraction and clean-up method of residual pesticides in liver of dead birds was used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LC and GC Orbitrap Mass Spectrometry. Results of method validations, Correlation coefficients of the matrix matched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from 69.1%to 130% (103% on average), and the precision values were less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detected monocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples. CONCLUSION: This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screening method is applicable to the residual pesticide analysis for the cause of death as a main tool.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.22-30
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• 2006

Phenolic acids of white ginseng were extracted and fractionated into free, esterified, and insoluble-bound forms. The contents of individual phenolic acids in different forms were quantified by gas liquid chromatography. Nine different phenolic acids as free, esterified, and insoluble-bound forms were identified in white ginseng. Total phenolic compounds in different forms of extracts was 0.309% (free form), 0.230% (esterified form) and 0.138% (insoluble-bound form), respectively. Total phenolic acid contents in free, esterified and insoluble-bound form were 889.3, 356.8, 1,176.9 mg/100g fraction, respectively. Ferulic acid was the predominant phenolic acid, representing 63.7% and 50.9% of total phenolic acids in esterified fom and insoluble-bound form, respectively. While caffeic acid was only detected in esterified form. At 10 mg/ml insoluble-bound form quenched 95.9% ABTS free radicals generated from 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH). Also, electron donating ability and lipid peroxidation inhibitory activity of insoluble-bound fom were higher than other fraction. All phenolic acid fractions scavenged over 80% of hydroxyl radical at 10 mg/ml.

• 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.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.232-241
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• 1998

Fatty acid compositions of 35 species of marine invertebrates (13 species of Bivalvia, 10 species of Gastropoda, 4 species of Cephalopoda, 4 species of Crustacea, 2 species of Ascidacea, 2 species of Holothuroidea) were studied using gas-liquid chromatography. Total lipids in all samples were very low, ranging from $0.24\%$ to $1.96\%$. The prominent fatty acids were 16:0, 20:5 (n-3), 22:6 (n-3), 18:0, 16:1 (n-7), 20:4 (n-6), 18:1 (n-9) and 18:1 (n-7) in the majority of marine invertebrates. Polyunsaturated fatty acid (PUFA) was the richest fatty acid group in all invertebrates, accounting for $55.3\pm6.70\%$ of total fatty acids (TFA), followed by saturated $(26.2\pm4.33\%)$ and monounsaturated fatty acid $(18.5\pm5.87\% )$. No correlation was found between total lipid content and each fatty acid group. Cephalopoda contained the highest level of n-3 PUFA $(54.6\pm5.17\%)$, while Holothuroidea and Gastropoda contained the lowest level of n-3 PUFA, accounting for $26.5\pm4.44\%$ and $28.4\pm4.04\%$, respectively. Bivalvia and Ascidacea are plankton feeders, which were rich in 20:5 (n-3) and 22:6 (n-3). Carnivorous species of Cephalopoda were prominently rich in 22:6 (n-3), ranging from $26.7\%$ to $46.1\%$ of the TFA. However, some species of Gastropoda are seaweed feeder (herbivorous), which contained high level of 20:4 (n-6) compared to plankton feeder and carnivorous species. In addition, blue and red colored sea cucumbers, and turban shells with and without apophyses belong to the same species, but they live in different habitats. These organisms were found to have different fatty acid compositions. Therefore, fatty acid compositions of these invertebrates might be affected by their different environments, particularly their diet.

• Journal of Applied Biological Chemistry
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• v.56 no.1
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• pp.29-35
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• 2013

This study was performed to analyze 48 kinds of pesticide residues using gas chromatography (GC)/nitrogen phosphorous detector, GC/micro electron capture detector, GC/mass selective detector, and high performance liquid chromatograph/diode array detector in 186 fresh ginseng samples collected in the Seoul area from 2010 to 2011. Fresh ginseng dietary intakes were estimated using the data from the 2009 Korea National Health and Nutrition examination survey. Residual pesticides were detected in 79 samples (42.5%) with eight different fungicides. Only 20 samples (10.8%) exceeded the maximum residue limits (MRLs) for pesticides registered by the Korea Food & Drug Administration. Among them, tolclofos-methyl residues (10.2%) exceeded the MRL for fresh ginseng in 18 ginseng seedlings and one of the two-year old fresh ginseng plants, and the residual level in just one ginseng seedling violated the MRL for pyrimethanil. The results showed that residual pesticides levels in marketable fresh ginseng around Seoul were relatively safe. The percent acceptable daily intake (%ADI) was calculated using pesticide residues in fresh ginseng and dietary intakes of fresh ginseng. The risk caused by pesticide residues in fresh ginseng was very low.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.175-180
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• 1984

Lipids in oyster mushroom (Pleurotus florida) were extracted by the mixture of chloroform-methanol (2: 1, v/v) and fractionated into neutral lipids, glycolipids and phospholipids by silicic acid column chromatography. Components and fatty acid composition of each fraction were deter- mined by thin-layer and gas-liquid chromatographies. Fresh oyster mushroom contained 0.5% total lipid in which the contents if neutral lipids, glycolipids and phospholipids were 33.8%, 19.7% and 45. 6%, respectively, Triglycerides(38.2%), free fatty acids (20%) and free sterol (10%) were the major components among the neutral lipids. Diglycerides, monoglycerides, sterol esters and three unidentified neutral lipids were the minor components. Major components of glycolipids were steryl glycosides(35.9%) and esterified steryl glycosides (23.7%). Digalactosyl diglycerides, mono-galactosyl diglycerides and two unknown components were also present. Of the phospholipids, phosphatidyl cholines and serines (48.2%), and phosphatidyl ethanolamines(44.4%) were the major components. On the other hand, the major fatty acids of neutral lipids we.e linoleic, palmitoleic, oleic and palmitic acid. Linoleic and palmitic acid were the predominant fatty acids of both glycolipids and phospholipids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.95-98
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• 1985

This study was carried out to investigate changes in the compositions of fatty acids according to the different drying methods of raw mugwort. Raw mugwort from Kang-wha was dried with four methods such as sun-drying, shady sun-drying, heated oven-drying and freeze-drying. Total contents and fatty acid compositions of the ethyl ether extracts from the dried mugworts were examined. Total contents of the ethyl ether extracts showed remarkable differences with drying methods; freeze-dried mugwort had the highest content (5.60%), while oven dried mugwort revealed the lowest content (2.45%). Eleven fatty acids and four unknown peaks were identified by gas-liquid chromatography; major fatty acids were linoleic acid, linolenic acid and palmitic acid. Fatty acids of mugworts dried by 4 different methods were the same in kinds, but different in their compositions. The content of polyunsaturated fatty acids $(C_{18:2}+C_{18:3})$ was the highest and the loss of low volatile fatty acids was the least in mugwort dried by the freeze-drying method. The volatile fatty acids considerably decreased in oven-dried mugwort. However, the contents of polyunsaturated fatty acids were a little higher in oven-dried mugwort than in sun-dried and shady sun-dried mugwort, and the lowest in sun-dried mugwort.

• Membrane Journal
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• v.27 no.6
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• pp.487-498
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• 2017

In this study, pervaporation performances of water/methanol and water/butanol mixture were evaluated using zeolite 4A membranes manufacutred by FINETECH by experimental works and numerical modeling. Permeation and separation characteristics, such as flux and separation factor, were analyzed by gas chromatography (TCD) and liquid nitrogen traps. Experiments have shown that water is selectively separated from a mixture of water and methanol (separation factor up to approximately 250) and water and butanol (separation factor up to approximately 1,500). Generalized Maxwell Stefan (GMS) theory was implemented to predict pervaporation behaviors of water/alcohol mixtures and diffusional coefficients of zeolite layer were obtained through parameter estimation using $MATLAB^{(R)}$ optimization toolbox. Since the pore size of zeolite 4A are much larger than kinetic diameter of water molecules and smaller than those of methanol and butanol, zeolite 4A membranes can be applied to in situ water removal process such as membrane reactors or hybrid reaction-dehydration process.