Ethyl Carbamate In Wine Research Articles

Analysis of ethyl carbamate in wines using solid-phase extraction and multidimensional gas chromatography/mass spectrometry.

The method describes a rapid and accurate procedure for the analysis of ethyl carbamate in wines. The separation of the ethyl carbamate (EC), the target analyte, from alcohol and the sample matrix is a challenge to many analytical chemists. After alcohol removal from the sample, EC was extracted and concentrated by solid-phase extraction. For analysis of EC, large-volume injection on a programmable temperature vaporization (PTV) inlet was used followed by multidimensional gas chromatography/mass spectrometry (MDGC/MS) using electron-impact ionization (EI). For quantitation, the ratio of ions produced during EI at m/z 62 (EC) and 64 (isotopically labeled EC) was monitored. The use of solid-phase extraction and MDGC/MS removes the majority of the matrix interference encountered in other methods. A linear dynamic range was established from 0.387 to 1160 ng/mL, with a limit of detection at 0.1 ng/mL and limit of quantitation at 1 ng/mL.

Determination of Ethyl Carbamate in Wine by Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry

A method for the rapid determination of ethyl carbamate in wine by headspace solid-phase microextraction with detection by gas chromatography/mass spectrometry has been developed. The analysis parameters of fiber coating, extraction time, and sample temperature have been optimized. The optimized method of headspace sampling with a Carbowax/divinylbenzene fiber for 30 minutes has been found to be reproducible and linear from 10 to 80 µg/L, with a limit of detection of 9.6 µg/L. The method is simple, requires little operator effort, and can be automated.

Urea Contribution to Ethyl Carbamate Formation in Commercial Wines During Storage

A two-year storage test using commercial wines confirmed that ethyl carbamate formation is closely related to the urea content. The ethyl carbamate formation rates at 10°C to 40°C were represented by linear equation against urea concentration in wine. Mathematical evaluation of the equations indicated that urea content in wine should be reduced to less than 2 mg/L in order to keep the ethyl carbamate content within the current target levels of the wine industry: 15 µg/L in table wines and 60 µg/L in dessert wines. It was found that, upon storage for six months at 40°C, ethyl carbamate level of the wines treated with acid urease was significantly lower than that of the untreated wines. The activation energy to form ethyl carbamate in wine was found to range between 21 kcal/mol and 28 kcal/mol which is similar to the activation energy level in other systems such as Japanese sake and simulated wine (a model wine system).

A method for the determination of methyl carbamate and ethyl carbamate in wines.

A method is described for the simultaneous determination of methyl carbamate (MC) and ethyl carbamate (EC) in wines that is based on: (a) extraction of the sample with dichloromethane using an extraction tube or an alumina-Celite column, (b) concentration of the extract to a small volume, and (c) determination by gas-liquid chromatography-thermal energy analyser (N-mode). The method is highly sensitive (1-2 ng/ml), accurate (recoveries greater than 80%), and precise (CV, 5-10%). Nineteen of 27 samples of wines analysed contained traces (up to 2.7 ng/ml) of MC, and most contained EC (up to 70 ng/ml). Wines treated in the laboratory with 200 ppm dimethyl pyrocarbonate (DMPC)-a cold sterilant recently approved for use in wines-indicated that such a treatment may increase the MC contents of the wines to 10 ng/ml. Additional studies suggested that formation of MC in DMPC-treated wines is dependent on both pH and ammonia content of the wines. The identity of MC in a few selected samples was confirmed by gas-liquid chromatography-high resolution (10 K) mass spectrometry. The natural low levels of MC found in these wines are not considered to pose a risk to human health.

Determination of ethyl carbamate in wine by GC‐SIM‐MS after continuous extraction with diethyl ether

Determination of ethyl carbamate in wine by GC‐SIM‐MS after continuous extraction with diethyl ether

Rapid Gas Chromatographic Method for Determining Ethyl Carbamate in Alcoholic Beverages with Thermal Energy Analyzer Detection

A rapid column elution method has been developed for the determination of ethyl carbamate (EC) in alcoholic beverages. The beverage is mixed with Celite and packed in a column containing deactivated alumina capped with a layer of sodium sulfate. EC is then eluted with methylene chloride. The method, using a gas chromatograph-thermal energy analyzer with a nitrogen converter for detection and quantitation of EC, has been applied to a variety of alcoholic beverages. Recoveries +/- standard deviations of EC in wine and whisky fortified at the 20 and 133 micrograms/kg (ppb) levels averaged 87.3 +/- 5.3 and 88.7 +/- 3.6%, respectively. The method has a limit of detection of 1.5 ppb. Gas chromatography/mass spectrometry/mass spectrometry was used to confirm the identity and quantitation of EC in selected beverage extracts.

ワイン中のカルバミン酸エチルの定量法

ワイン中のカルバミン酸エチルの定量法

Residue levels of ethyl carbamate in wines and spirits by gas chromatography and mass spectrometry/mass spectrometry.

Residue levels of ethyl carbamate in wines and spirits by gas chromatography and mass spectrometry/mass spectrometry.

Radioimmunoassay Method for Analysis of Ethylcarbamate in Wine

An attempt to develop a radioimmunoassay method for analysis of ethylcarbamate failed because the presence of ethylcarbamate antibodies in supposedly normal goat serum caused the second antibody precipitation reaction to become nonspecific. This suggested possible contamination of the sera samples. To check this further tests were made with goat anti-DNA, goat anti-myosin, three other goat sera, and three fresh human sera. All sera tested reacted positively with ethylcarbamate. These findings point to the possible widespread occurrence of anti-ethylcarbamate sera.

Radioimmunoassay Method for Analysis of Ethylcarbamate in Wine

An attempt to develop a radioimmunoassay method for analysis of ethylcarbamate failed because the presence of ethylcarbamate antibodies in supposedly normal goat serum caused the second antibody precipitation reaction to become nonspecific. This suggested possible contamination of the sera samples. To check this further tests were made with goat anti-DNA, goat anti-myosin, three other goat sera, and three fresh human sera. All sera tested reacted positively with ethylcarbamate. These findings point to the possible widespread occurrence of anti-ethylcarbamate sera.

Fate of Diethyl Pyrocarbonate in Wine

DEPC-C¹⁴ added to water hydroyzed completely to yield ethyl alcohol and carbon dioxide. However, when this compound was added to wine only a 97 to 98 per cent hydrolysis took place at pH 3.3, as measured by the labeled carbon dioxide given off. The 2 to 3 per cent DEPC-C¹⁴ which was unaccounted for is presumed to form pyrocarbonate complex with some wine constituent but this complex was hydrolyzed at pH 1.0 despite the fact that it is relatively stable at the normal pH range of wines. When labeled carbon dioxide was added to wine in the form of sodium carbonateC¹⁴ a small but consistent residual radioactivity was observed at pH 3.3 and also at pH 1.0. The carbonate complex formed in DEPC treated wines did not seem to be a reaction product between DEPC and organic acids, sugars, ethanol or higher alcohols in the wine; it is also unlikely that the amino acid content of the wine was responsible for this product since N-carbethoxyamino acids, the reaction products between DEPC and amino acids, were not hydrolyzed even by prolonged heating at pH 1.0. Tannic acid appeared to react with DEPC to give a complex which is hydrolyzable at pH 1.0 and it is suspected that this was at least a partial cause for the observed residue in DEPC-treated wine. The possibility of DEPC reacting with ammonium ions to form ethyl carbamate in wine is currently being investigated.