|Underivatized LC-MS/MS determination of ethyl carbamate in wines
|Mr João Micael Leça
|Dr Vanda Pereira
Dr Ana Cristina Pereira
Dr Jose Carlos Marques
|Faculty of Exact Sciences and Engineering - University of Madeira
Abstract Information :
Ethyl carbamate (EC) is formed in fermented foods and beverages, namely in fortified wines, by the reaction of nitrogen compounds with ethanol. It is recognized as a toxic compound and was reclassified in 2007 by the International Agency of Research on Cancer as probably carcinogenic to humans (group 2A). The technological advance boosted the simplification of the EC determination, which has been gaining attention, since has been playing an important role in its prevention and control.
This work presents the optimization of a miniaturized liquid-liquid extraction (mLLE) followed by reversed-phase liquid chromatography-electrospray tandem mass spectrometry (RP-HPLC-MS/MS) for the determination of ethyl carbamate (EC) in fortified wine, without using derivatizing agents.
To optimize the mLLE extraction, a full factorial design was carried out, considering two factors, the sample and extraction solvent volumes. The optimum conditions, which maximize the EC chromatographic peak area in the HPLC-MS/MS equipment, were 15 mL of fortified wine sample combined with 8 mL of ethyl acetate. The characteristic secondary ion transition of EC (m/z = 90.10→62.05) was used for quantification purposes. The method showed good linearity (R2 = 0.9999), high sensitivity (LOQ = 0.52 µg L−1), good precision (repeatability and reproducibility <8% of variation) and high accuracy, with recoveries varying between 93 and 114%. The applicability was confirmed through the analysis of 24 fortified wines, with EC values ranging between 23 ± 1 and 194 ± 5 µg L−1.
This eco-friendly method based on mLLE and RP-HPLC-MS/MS was successfully developed, ensuring a good compromise between sensitivity and low usage volumes. Additionally, it provides a favourable extraction of EC in less than 15 min and a LC-MS/MS analysis in 18 min, which is a great contribute for the simplification of the EC determination in wines, and also for mitigation and control purposes .