Identification and quantification of volatile toxic compounds in tequila

Abstract

Nitrosoamines (NAms), methanol and furfural are toxic compounds that are frequently found in low concentrations in alcoholic beverages and food products. NAms such as Nitrosodimethylamine, Nitrosodiethylamine, Nitrosodibutylamine, Nitrosopiperidine and Nitrosopyrrolidine are considered cancerogenic and mutagenic compounds whereas furfural and methanol can lead in skin cancer and eye damage respectively. Therefore, in this work these compounds were analyzed in tequila (white, rested and aged), which is an important and highly consumed beverage. The technique of headspace solid-phase micro-extraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used for its simplicity, speed, high precision and its environmental friendliness. The influence of the important extraction parameters such as temperature (Teq), equilibrium time (teq), extraction time and ionic strength was evaluated through a factorial analysis. The quantification was carried out using the standard additions method. In order to validate the methodology, the limits of detection and quantification were determined. Amongst the NAms, the NDBA was the only NAm detected in all the tequila samples studied. The maximum concentrations found of NDBA, furfural and methanol were 7.33 µg/L, 0.95 mg/100 mL anhydrous alcohol and 132.51 mg/100 mL anhydrous alcohol. These amounts were within the limits considered safe for human consumption by the Environmental Protection Agency and Mexican norms.