Ethyl Carbamate In Spirits Research Articles

A novel derivatization method for the determination of ethyl carbamate in spirits by liquid chromatography with spectrophotometric detection

A novel derivatization method for the ethyl carbamate (EC) determination is introduced, representing a significantly more promising approach to the only previously described and time-demanding EC derivatization with the expensive 9–xanthydrol agent. The presented derivatization procedure utilizes a 4–(dimethylamino)benzaldehyde (p-DMAB) reagent to form a derivative with a recovery of 99.4 %. The quantitative EC reaction with p-DMAB proceeds within five minutes without any considerable by-products and the resulting derivative was confirmed by mass spectrometry. The derivatization procedure led to the development of a new chromatographic method with spectrophotometric detection at 420 nm for EC determination in spirits. The achieved quantification limit of 582.5 µg L–1 complies with the recommendation of the European Commission from 2010, demonstrating its practical use in food safety control. Within the optimization of detection, the electrochemical behaviour was included to reveal the possibility of amperometric detection. Compared to the method used so far, the proposed approach significantly reduces the cost and time required to screen this potential carcinogen and could lead to the manufacture of commercial colorimetric assay kits detecting hazardous EC concentration levels.

Determination of ethyl carbamate in spirits using salting-out assisted liquid–liquid extraction and high performance liquid chromatography with fluorimetric detection

In this work, a simple methodology was developed for the determination of ethyl carbamate (EC) in spirits by high performance liquid chromatography with fluorimetric detection. The sample is subjected to salting-out assisted liquid–liquid extraction (SALLE) using a 9-xanthydrol/acetonitrile solution for the simultaneous extraction and derivatisation of EC. Extraction/derivatization occurs under acidic conditions (0.5 mol L−1 HCl) and NaCl was used for phase separation. The methodology showed low limits of detection and quantification (9 μg L−1 and 23 μg L−1, respectively) and good precision (4.4% intraday and 8.7% interday). The determined EC concentrations in the analysed samples varied between 51 and 266 μg L−1. The proposed sample preparation methodology is simple and low cost, it uses limited toxicity solvents and the obtained extract is readily compatible with reversed phase liquid chromatography. Moreover, the stability of the xanthyl-EC product was verified. More importantly it is a more robust alternative to the liquid chromatography based methodologies that do not apply any extraction procedure, which do not consider the problems associated with the long term deterioration of the analytical systems.

Rapid Quantification of Ethyl Carbamate in Spirits Using NMR Spectroscopy and Chemometrics

Ethyl carbamate (EC, urethane, C2H5OCONH2) is a genotoxic carcinogen and is regularly found in fermented food products including alcoholic beverages. In this study, the rapid method of nuclear magnetic resonance (NMR) spectroscopy in combination with partial least squares (PLS) regression is applied for the first time to the analysis of ethyl carbamate in stone fruit spirits () and unrecorded alcohols () (analysis time only 15 min per sample). The PLS procedure was validated using an independent set of samples (, , mg/L) in comparison to reference GC/MS/MS results. The NMR method was found to outperform other screening techniques based on NIR or FTIR regarding sensitivity and selectivity. The major advantage over GC/MS/MS, besides the reduced time of instrumental analysis, is that no sample preparation besides addition of buffer with internal standard is required, while for GC/MS/MS labour-intensive sample extraction is necessary prior to measurement.

Retrospective trends and current status of ethyl carbamate in German stone-fruit spirits

Ethyl carbamate (urethane, C2H5OCONH2) is a known genotoxic carcinogen of widespread occurrence in fermented food and beverages with highest concentrations found in stone-fruit spirits. Between 1986 and 2004, 631 cherry, plum or mirabelle (yellow plum) spirits were analysed for ethyl carbamate using gas chromatography in combination with mass spectrometry after extrelut extraction. The ethyl carbamate concentration of the samples ranged between 0.01 mg l−1 and 18 mg l−1 (mean 1.4 mg l−1). After exposure of the samples to UV light, significantly (p = 0.001) higher concentrations between 0.01 mg l−1 and 26 mg l−1 (mean 2.3 mg l−1) were found. The ethyl carbamate concentration increased on average by 1.3 mg l−1. A linear correlation between the year of sampling and ethyl carbamate concentration showed a statistically significant but very slight decrease (R = −0.10, p = 0.024). However, if only samples which officially were non-compliant were considered exceeding the upper limit of 0.4 mg l−1 more than twice, a significant reduction (R = −0.56, p = 0.018) of the quota was evident. This shows that measures to reduce ethyl carbamate were successfully introduced in many distilleries. However, nearly 20 years after the first warnings about ethyl carbamate in spirit drinks, the problem persists especially in products derived from small distilleries. During experimental production of stone-fruit spirits using state-of-the-art technologies, it was shown that the occurrence of ethyl carbamate in stone fruit spirits is preventable. Even for small distilleries, simple possibilities like destoning exist to minimize the ethyl carbamate content.

Copper(II) catalysis in cyanide conversion into ethyl carbamate in spirits and relevant reactions.

The role of copper(II) species in the oxidation of inorganic cyanide to cyanate and in the conversion of cyanate or urea into ethyl carbamate was investigated. The oxidation process has been shown to be independent from the dissolved oxygen. Elemental analysis and infrared spectroscopy have shown the formation of a mixed copper carbonate/hydroxide in the process of oxidation of cyanide to cyanate in water/ethanol. The complexation to Cu(II) of cyanate formed upon cyanide oxidation makes the former more susceptible to nucleophilic attack from ethanol, with conversion into ethyl carbamate. Comparatively, urea has a minor role with respect to cyanide in the formation of ethyl carbamate. Therefore, the urea present in some samples of Brazilian sugar cane spirit (cachaça) has been shown to have almost no influence on the ethyl carbamate content of cachaças, which comes essentially from cyanide. Fe(II,III) affords results similar to those found with Cu(II). Some suggestions are presented to avoid ethyl carbamate formation in spirits during distillation.