• Food Science and Biotechnology
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• v.15 no.1
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• pp.112-116
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• 2006

Levels of ethyl carbamate, by-product produced naturally during fermentation, in Korean alcoholic beverages were determined by Gas Chromatography/mass spectrometry/selected ion mode (GC/MS/SIM), and their daily intake by Korean adult group was estimated. In GC/MS/SIM analysis 0.8-10.1, 0.5-0.8, 0.4-0.9, 3.5-689.9, 8.4-30.3, 13.9-30.0, and 1.7-11.7 ppb of ethyl carbamate were detected in soju, beer, takju, fruit wine, cheongju, whiskey, and grape wine, respectively. Maximum daily exposure of ethyl carbamate through alcoholic beverage consumption was 7.41 ng/kg body weight/day for average Korean male, with one soju brand and two fruit wine brands showing high ethyl carbamate level.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.697-705
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• 2003

The alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) followed by two work-up methods for comparison: isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. Eleven endocrine disrupting chemicals (EDCs) of phenols in biological samples were extracted with acetonitrile and then the acetonitrile layer underwent freezing filtration 6$0^{\circ}C$ for 2 hours. Solid-phase extraction (SPE) was used with XAD-4 and subsequent conversion to isoBOC or TBDMS derivatives for sensitivity analysis with the GC/MS-SIM mode. For isoBOC derivatization and TBDMS derivatization the recoveries were 92.3∼150.6% and 93.8∼108.3%, the method detection limits (MDLs) of bisphenol A for SIM were 0.062 $\mu$ g/kg and 0.010 $\mu$ g/kg, and the SIM responses were linear with the correlation coefficient varying by 0.9755∼0.9981 and 0.9908∼0.9996, respectively. When these methods were applied to mackerel samples, the concentrations of the 11 phenol EDCs were below the MDL.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.391-398
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• 1989

Triglyceride molecular species In some vegetable oils were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. Triglycerides were separated according to their molecular weights and their degrees of unsaturation on $25m{\times}0.25mm$ fused silica open tubular capillary column coated with a phenylmethylsilicone gum stationary phase and in an analysis time less than 13 min. Triglyceride molecular species were identified by analyzing the fragment ions having the same time on the selected ion monitoring profile . The major triglyceride molecular species in each oils were $C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL:18.3%),\;C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;14.3%),\;C_{18:0}.\;C_{18:2}.\;C_{18:2}(SLL;\;14.1%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;13.2%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;11.6%)$ in corn oil, $C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;18.0%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;18.0%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;17.1%)$ in safflower oil, $C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;23.5%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;13.8%),\;C_{18:0}.\;C_{18:1}.\;C_{18:1}(SOO;\;13.5%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;10.6%)$ in cottonseed oil.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.293-304
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• 2006

Sea water samples collected in August, 1994 from 20 stations in the Kwangyang Bay were analyzed by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) to investigate persistence and distribution pattern of four organophosphorus pesticides (DDVP, Diazinon, IBP, EDDP). Except for IBP, the contamination by DDVP, Diazinon, and EDDP in marine aquatic environment in Korea has not been reported previously. In this study, however, all these four pesticides were detected in all stations (except DDVP) and their concentrations were in ng/L level. The concentrations ranged from detection limit to 15.3ng/L for DDVP, 1.8-27.7ng/L for Diazinon, 7.3-63.5ng/L for IBP, and 22.2-1100.1ng/L for EDDP. It is noteworthy that the measured concentrations of IBP and EDDP in this study would be much lower than usual, since the use of IBP and EDDP was less than 50% of average annual consumption due to unusually dry and hot weather condition in the summer of 1994. It was very surprising to find that the highest concentrations of organophosphorus pesticides were observed at stations near Daesa Streamlet instead of Seomjin River, which has more point source of the pesticides. This result suggests that the small river discharge during heavy ram period in summer can give harmful effect on marine biota (both wild and aqua-cultured) with its organophosphorus pesticide residue, despite of their short residence time in aquatic environment. In order to protect the marine life properly from acute toxicity of the organophosphorus pesticides, it needs to be emphasized that monitoring the level of agricultural pesticides in river run-off should be done during active consumption period rather at regular intervals.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.975-980
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• 2007

Determination of ethyl carbamate content in imported alcoholic beverages in Korea and an exposure assessment were conducted. In gas chromatography/mass spectrometry/selected ion monitoring (GC/MS/SIM) analysis, 2.5-39, 8-263, 6.3-112, 11.3-23.5, 53-94, 8.5-38.5, 7-9.5, 21.3-31.5, 5-832.5, and $10.5-364.8\;{\mu}g/L$ of ethyl carbamate were detected in imported beers, sakes, whiskies, vodkas, Chinese liquors, cognacs, tequilas, rums, liqueurs, and wines, respectively. The exposure assessment indicated that the exposure of Korean adults to ethyl carbamate were lower than 20 ng/kg BW per day, (the virtual safe dose) indicating that the amount of ethyl carbamate exposed through fermented food and alcoholic beverages including imported products are currently in the 'no significant risk level'. However, the present low exposure to ethyl carbamate through the imported alcoholic products was not due to the low contents of ethyl carbamate in imported products, but low consumption of the imported products. Therefore, given increasing importation of alcoholic beverages in Korea, reductions of ethyl carbamate content in imported alcoholic beverages, especially non-distilled products, should be required by regulating limits on the ethyl carbamate content in the imported alcoholic beverages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.205-210
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• 1989

The influence of triglyceride molecular species on autoxidation was investigated by determining the residual molecular species after incubating soybean oil triglycerides. The molecular species of soybean oil triglycerides were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. The autoxidative stability of each molecular species in soybean oil triglycerides appeared to decrease in proportion to the increase in the number of double bonds present in the acyl residues, and it was affected by degree of unsaturation of fatty acid when the number of double bonds in triglyceride were the same. And it appeared to be enhanced by a decreases in the length of the saturated acyl chain present in the glycerides.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.122-127
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• 2001

4-tert-octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. Also, OP is known to have estrogenic activity by interacting with development and functions of endocrine system. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley rats. Male rats were administered OP, by either single oral (gavage) applications of 50, 100 or 200 mg/kg body weight. or a single intravenous injections of 1, 5 or 10 mg/kg body weight. Blood samples taken at several time intervals after administration were obtained from the femoral artery. Analysis of blood samples for OP was performed by gas chromatography mass spectrometry (GC/MS). The detection limit of OP was 1.9 ng/$m\ell$ at SIM (selected ion monitoring) mode of GC/MS. Calibration curve for analysis of the concentrations of OP in plasma was (OP/butylphenol peak area ratio) = 0.0294 $\times$ (plasma cone.) + 0.028 ($r^2$= 0.9991). The OP plasma concentration was 3921 ng/$m\ell$ immediately after single intravenous application, decreased rapidly within 45 min, and was detectable at low concentration up to 6 hr after application. When administered orally in rats (50, 100 and 200 mg/kg), OP was detected in the blood early after gavage administration, indicating the rapid initial uptake from gastrointestinal tract, with Tmax obtained from 0.67~0.83 hr. Using the AUC (area under the curve) of plasma concentration vs. time, low oral bioavailabilities of 1.2, 5.0 and 5.3% were calculated for the 50, 100 and 200 mg/kg groups, respectively.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.159-164
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• 1990

To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.421-427
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• 1996

Ethyl carbamate is an animal carcinogen and a suspected human carcinogen found in fermented foods and beverages. For the determination of ethyl carbamate in typical Korean diet, an analytical method was established for the food as complex as Kimchi. Kimchi samples collected from various locations in the country were homogenized and extracted four times with ethyl acelate. Following concentration and reconstitution with water, the extract was loaded onto $C_{18}$ column. Fraction containing ethyl carbamate was eluted with methanol, while most of the red pigment of the sample was retained on the column. The eluent was further purified with alumina, followed by Florisil column. The final eluent was analyzed by gas chromatography mass spectrometry in the selected ion monitoring mode. None of the twenty Kimchi samples showed ethyl carbamate level higher than 4.6 ppb without correction for the recovery. The concentration of ethyl carbamate in Kimchi increased as pH decreased, suggesting fermentation dependent formation of ethyl carbamate.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.7-12
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• 1990

The effect of $Fe^{2+}$ and myoglobin on the oxidative stability of triglyceride molecular species was investigated at $25^{\circ}C$. The molecular species of soybean oil triglycerides were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. When $Fe^{2+}$ and myoglobin were added to soybean oil triglycerides, the oxidative stability of each molecular species of triglycerides appeared to decrease in proportion to the increase in the number of double bonds present in the acyl residues, and it was affected by degree of unsaturation of fatty acid when the total degree of unsaturation of triglyceride was the same. But the length of the saturated acyl chain had no influence on the stabilization of unsaturated fatty acid present in the same glyceride when prooxidants were added.