• Korean journal of food and cookery science
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• v.33 no.2
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• pp.121-126
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• 2017

Purpose: This study measured the ethyl carbamate (EC) content in commercial and home-made soy sauce and examined the effects of cooking methods, such as boiling and pan-frying, on the EC content. Methods: A total of 20 soy sauce samples including 14 home-made and 6 commercial products were analyzed according to the AOAC official method with some modifications. To simulate conventional boiling, soy sauce containing EC ($14.59{\mu}g/kg$) was heated to $100^{\circ}C$ for four different times: 10, 20, 30, or 40 min. Pan-frying was conducted for 4 min at $170^{\circ}C$. Results: EC was not detected in any of the homemade samples, whereas it was found in the commercial samples, ranging from 2.51 to $14.59{\mu}g/kg$. The concentrations of EC increased gradually with increasing boiling from 14.59 to $26.54{\mu}g/kg$, whereas pan-frying did not affect the EC level in soy sauce. Conclusion: These results indicate that EC is formed by a reaction between the EC precursors during boiling, suggesting that the cooking method of each food should be considered when estimating the dietary exposure to EC.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.2
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• pp.309-315
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• 2015

This study aimed to develop and validate an analytical method for ethyl carbamate (EC) in Maesilju. For accurate analysis of EC in Maesilju, an internal standard (d5-EC) and neutralization (pH=7) were performed. The limit of quantification (LOQ) was 3.65 ppb while the recovery rate ranged from 92.54% to 103.59%. Intra- and inter-day precision ranged from 0.87% to 1.99% and 2.67% to 5.64%, respectively. Maesilju samples comprised 10 homemade and five commercial ones. Samples contained EC at levels between 118.48 and 2,640.42 ppb. The average content of homemade Maesilju was higher than those of commercial ones. Based on manufacturers' labeling of commercial samples and information on homemade samples, various factors such as ingredients and soaking time of Maesil affected EC level in Maesilju. EC contents showed a positive correlation with age of Maesilju.

• Analytical Science and Technology
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• v.21 no.1
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• pp.53-57
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• 2008

In order to survey the contents of ethyl carbamate in alcoholic beverages, GC/MS-SIM method was used after extraction with dichloromethane in solid phase extract cartridge contained alcoholic beverages. In the applied GC/MS-SIM method, the values of recoveries and relative standard deviation were ranged from 85.2 % to 87.9 % and from 0.7 % to 1.9 %, the limit of detection and quantification were $2{\mu}g/kg$ and $10{\mu}g/kg$. Depending on alcoholic beverage kinds, the levels were variable and the average level was $194{\mu}g/kg$ for liquor, $105{\mu}g/kg$ for fruit wine, $62{\mu}g/kg$ distilled spirit, $28{\mu}g/kg$ for sake, $15{\mu}g/kg$ for yakju, $12{\mu}g/kg$ for other alcohol beverages, ND for soju, respectively.

• YAKHAK HOEJI
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• v.18 no.4
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• pp.255-258
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• 1974

The insecticidal activity of six lately synthesized carbamate derivatives of furfural oxime N-methylcarbamate (I), 5-methyljural oxime N-methylcarbamate (II), methyl p-(methylcarbamoyl) oxybenzoate (IV), ethyl p-(methylcarbamoyl) oxybenzoat(V), n-propyl p-(methyl carbamoyl)oxybenzoate(VI) and n-butyl p-(methyl carbamoyl)oxybenzoate examined using o.2w/v% acetone solutions of each compound. Among them, alkyl p-(methyl carbamoyl) oxybenzontes exerted slightly insecticidal effects on Sogata furcifera H$_{ORVATH}$, Delphacodes stria striatella FALLEN, wherease no significant effects were observed on Mil-aparvata Iugens Stal, Inazuma dorsolis Moischiulsky, and Naphotettix apicalis cincticeps U$_{HLER}$.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.147-151
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• 2005

A$(-)-\alpha$-narcotine from Papaver sommiferum was refluxed with ethyl chloroformate to give the diastereomeric chloro-carbamate mixture and the Z/E-enol lactones as Z:E=1:1.1 ratio in HPLC analysis. After photoisomerization with UV (254 nm), the Z/E ratio was drastically changed to Z:E=7:1, which may indicate that the E-isomer was easily converted to the Z-isomer due to photoisomerization. The photoisomerization of the Z/E-enol lactones and the different stereochemistry of the degradation product of $\beta-narcotine$, deuterated $\beta-narcotine$ and $\beta-narcotine$ with ethyl chloroformate will also be discussed.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.723-728
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• 1998

The chemical behaviours of 4-methyl-2-oxo-2H-benzopyran-7-yl oxoacetyl hydrazine (2) towards some different reagents such as anhydride compounds, aromatic aldehydes, carb on disulphide, and nitrous acid yielded the corresponding pathalazine derivatives (3, 4, 5), hydrazone derivative (6), 1,3,4-oxadiazole derivative (7, 8, 9) and acid azide (10) respectively. Treatmen of 10 with absolute alcohols, amines and ethyl amino acid ester gave the corresponding carbamate derivative (11), substituted urea derivative (12) and ethyl substituted alkyl acetate (13) respectively. The biological activity of some synthesized compounds was evaluated.

• Bulletin of the Korean Chemical Society
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• v.12 no.4
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• pp.373-376
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• 1991

Degradation of (-)-laudanosine, a 1-benzyl-1,2,3,4-tetrahydroisoquinoline alkaloid, with ethyl chloroformate (ECF) afforded an optically active chloro-carbamate as an intermediate. The reason why this intermediate exhibits an optical activity was investigated by comparison with the reactions of some model compounds with ECF. It may be supposed that the chloride group in a hypothetic carbenium ion intermediate stands very closely to the chiral center, so conserving optical activity. However, a neighboring group effect can not be excluded.

• Food Science and Preservation
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• v.20 no.3
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• pp.429-434
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• 2013

This study was designed to investigate the formation of ethyl carbamate (EC) during the ripening of Maesil with sugar and Soju (19.5~35% alcohol contents) using a homemade method. Maesil, sugar and Soju were purchased at ordinary market in June of 2012. The preparation of sample for analysis was conducted by method of Henry et al. The analysis of GC/MS was used SIM mode (m/z 89, 74, 62). Quantification was performed in terms of the 62 ion and was based on an internal standard procedure. Good linearity was obtained with a regression coefficient ($r^2$ = 0.993). Low detection limits (LOD) was achieved 4.31 ug/kg and recovery for alcohol was 74.8%. During 90 days, fermentation with sugar was not detected EC (under LOQ). 15 days ripened Maesil wine contained EC between non detected~32.7 ug/kg and 90 days ripened Maesil wine was 19.7~87.4 ug/kg. Higher proportion of Maesil and Soju increased EC contents. EC levels were increased 32.7 ug/kg to 87.4 ug/kg in the ratio of Maesil to 35% alcohol-Soju (1:1). In the ratio of Maesil to 35% alcohol-Soju (1:3) was increased non detected to 69.7 ug/kg. After 90 days, Maesil wine was filtered Maesil through a seive and ripened by 180 days to investigate the formation of EC compared with non filtered. Treatment of filtered, EC contents was much higher level compared with non filtered. Therefore, this result showed that alcohol contents contribute to increase EC formation more than Maesil.

• Korean journal of applied entomology
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• v.20 no.4 s.49
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• pp.223-227
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• 1981

These experiments were conducted to investigate the nematicidal effects of the insecticides, Mocap(O-Ethyl-S, S-dipropyl phosphorodithioate), Carbofuran(2,3-Dihydro-2,2-dimethyl benzofuranyl ethyl carbamate), Terbufos (S-tert-buthylthio methyl O,O-diethyl phosphordithioate) and their mixtures (Mocap+carbofuran, Mocap+Terbufos, Carbofuran+Terbufos) on growth of 2year-old ginseng, Panax ginseng C.A. Meyer, and the control of root-knot nematodes. There was no evidence of plant injury from insecticide treatment of ginseng, although the rate of emergence of the treated ginseng was slightly inhibited. The insecticide treatments showed no of-flavor of ginseng plant. Terbufos and Mocap provided heifer confrol of the root-knot nematodes than carbofuran alone and their mixtures. Mixtures of the insecticides showed antagonisitic effect to the root-knot nematodes.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.67-75
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• 1986

This study was undertaken to investigate the interrelation between herbicide and insecticide and fungicide on rice (Oryza saliva L.) at various growth stages. Carbamate insecticide BPMC (2-sec-butylphenylmethyl-carbamate) severely inhibited germination of rice when applied alone and in combination with herbicides tested. No germination inhibition was obtained with thio- and dithiocarbamate pesticides. Post-germination growth of rice was severely inhibited by the treatments which were combined with BPMC irrespective of herbicides studied. Phytotoxicity of pendimethalin (3,4-dimethyl-2,6-dinitro-N-1-ethyl propylamine) was reduced by antagonistic effect of organophosphorus compounds. When herbicides were applied with either insecticide or fungicide, post-germination growth of rice was more greatly affected by the concentration of herbicides than that of insecticides or fungicides. Most of herbicide-insecticide or herbicide-fungicide treatments did not cause great phytotoxicity on rice when applied 5 days after transplanting. Foliage activity of phenoxy herbicide 2,4-D (2,4-dichlorophenoxy acetic acid) and MCPA [(4-chloro-o-tolyl) oxy acetic acid] increased with addition of carbamate and urea pesticides.