Determination of Ethyl Carbamate in Commercial Sweetened Sugar Cane Spirit by ESI-MS/MS Using Modified QuEChERS and 18-Crown-6/Trifluoroacetic Acid Spiking Additives

A fast, sensitive, and selective direct injection electrospray tandem mass spectrometry (DI‑ESI‑MS/MS) method that is able to quantify ethyl carbamate in commercial sweetened sugar cane spirit is described. The preparation method uses a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) with potassium carbonate added to sweetened sugar cane spirit to separate the aqueous phase from the ethanol phase. The aqueous phase contains sucrose that suppresses electrospray ionization. Ethyl carbamate supernatant from the ethanol phase is transferred and enriched with 18-crown-6/trifluoroacetic acid additives. The additives sequester metal cations reducing the ionization of sodium and potassium, favoring the detection of ethyl carbamate as sole protonated cations. The method was successfully applied for the quantification of eleven real samples and certified sugar cane spirit demonstrating its applicability for quality control and regulatory analysis. The method showed reliable analytical parameters compared to conventional gas chromatography mass spectrometry (GC-MS) method commonly used for ethyl carbamate analysis. DI-ESI-MS/MS method requires just a fast step sample clean up and presents consistent values for the limit of detection (LOD 48.0 μg L−1) and limit of quantification (LOQ 160.0 μg L−1). Furthermore, the recoveries obtained were close to 100%, with relative standard deviations below 10% of sample certificates.

Evaluation of Nitrite, Ethyl Carbamate, and Biogenic Amines in Four Types of Fermented Vegetables

Nitrite, ethyl carbamate, and biogenic amines in fermented vegetables are considered harmful compounds. In this study, the concentration of the nitrite, ethyl carbamate, and biogenic amines in four different varieties of fermented vegetables in China was determined. The results show that the nitrite concentration in the fermented cabbage was the highest, followed by fermented mustard, fermented bamboo, and fermented radish. Additionally, nitrite concentration in two fermented cabbage samples and one fermented mustard sample exceeded the maximum allowed residue limit (20 mg/kg) suggested by China’s National Food Safety Standards. However, only one fermented cabbage sample had a very low level of ethyl carbamate (<10 μg/kg). Otherwise, higher biogenic amines were found in the samples of fermented cabbage, fermented bamboo, and fermented mustard. Additionally, the concentration of biogenic amines in some samples exceeded the recommended limit. On the contrary, biogenic amines in fermented radish samples were relatively low. Therefore, the concentration of nitrite and biogenic amine should be closely monitored and controlled during the vegetable fermentation processes, especially for the fermentation processes of bamboo, cabbage, and mustard.

Evaluating the chemical and metal contamination of commercial Rakı, a grape-based alcoholic beverage from Turkey

Turkish Rakı is one of the most consumed alcoholic beverages in Turkey. The chemical and metal contamination of alcoholic beverages is a threat to human health and lowers the quality of the product. Ethyl carbamate and furfural are carcinogenic to animals, and have been classified as Group 2A and 3 agents respectively by the International Agency for Research on Cancer. Factors, such as raw materials, process time and storage, affect metal concentrations in beverages. Limits for chemicals and metals in Rakı have not yet been established by the Turkish agency. The present study aimed to evaluate the chemical and metal contamination of commercial Turkish Rakı. Thirty-seven different types of Turkish Rakı were purchased from local markets in Turkey. Ethyl carbamate (EC) and furfural (FR) levels were measured by Gas Chromatography-Mass Spectroscopy (GC-MS). Arsenic, copper, lead, and zinc levels were measured by Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES). None of the Rakı samples contained EC. Furfural was not detected in commercial Rakı samples but only in illegal Rakı samples. Ethanol and methanol levels complied with Turkish regulation. Our data shows that commercial Rakı from Turkey was contaminated by very low amounts of arsenic (<LOD–0.02 mg/L), copper (0.05–0.41 mg/L), lead (< LOD–0.03 mg/L) and zinc (0.01–0.39 mg/L).

Occurrence of Ethyl Carbamate in Foods and Beverages: Review of the Formation Mechanisms, Advances in Analytical Methods, and Mitigation Strategies

Ethyl carbamate (EC) is a process contaminant that can be formed as a byproduct during fermentation and processing of foods and beverages. Elevated EC levels are primarily associated with distilled spirits, but this compound has also been found at lower levels in foods and beverages, including breads, soy sauce, and wine. Evidence from animal studies suggests that EC is a probable human carcinogen. Consequently, several governmental institutions have established allowable limits for EC in the food supply. This review will discuss EC formation mechanisms, occurrence of EC in the food supply, and EC dietary exposure assessments. Analytical methods currently used to detect EC, and advances in experimental technologies, such as nanosensors and surface-enhanced Raman spectroscopy (SERS) will also be discussed. Finally, application of mitigation methods to maintain levels of EC under allowable limits will be covered, including distillation practices, enzymatic treatments, and genetic engineering of yeast. Ongoing research in this field is needed to refine mitigation strategies and develop methods to rapidly detect EC in the food supply.