Analysis of methanol and ethanol in virgin olive oil

Raquel B Gómez-Coca; Rosario Cruz-Hidalgo; Gabriel D Fernandes; María Del Carmen Pérez-Camino; Wenceslao Moreda

doi:10.1016/j.mex.2014.09.002

Analysis of methanol and ethanol in virgin olive oil

MethodsX. 2014 Sep 23:1:207-11. doi: 10.1016/j.mex.2014.09.002. eCollection 2014.

Authors

Raquel B Gómez-Coca¹, Rosario Cruz-Hidalgo¹, Gabriel D Fernandes², María Del Carmen Pérez-Camino¹, Wenceslao Moreda¹

Affiliations

¹ Instituto de la Grasa - CSIC, Avda. Padre García Tejero 4, E-41012 Sevilla, Spain.
² Fats and Oils Laboratory, Faculty of Food Engineering, University of Campinas, 13083-970 Campinas, SP, Brazil.

Abstract

This work provides a short and easy protocol that allows the analysis of both methanol and ethanol in the static headspace of olive oil. The procedure avoids any kind of sample pre-treatment beyond that of heating the oil to allow a maximum volatile concentration in the headspace of the vials. The method's LOD is 0.55 mg kg(-1) and its LOQ is 0.59 mg kg(-1). Advantages of this method are:•Simultaneous determination of methanol and ethanol (the pre-existing Spanish specification UNE-EN 14110 only analyses methanol).•No need of equipment modifications (standard split injectors work perfectly). Use of a highly polar capillary GC column, leading in most cases to chromatograms in which only three dominant peaks are present - methanol, ethanol, and propanol (that is extremely positive for easy interpretation of results).•Use of an internal standard (1-propanol) to determine the concentration of the analytes, reducing the presence of error sources.

Keywords: Analysis of static headspace virgin olive oil volatiles; Analysis of volatiles; Ethanol determination; Fatty acid alkyl esters (FAAE); Methanol determination; Olive oil; Virgin olive oil volatiles.