Determination of synthetic phenolic antioxidants in soft drinks by stir-bar sorptive extraction coupled to gas chromatography-mass spectrometry

Abstract

The synthetic phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) were pre-concentrated by stir-bar sorptive extraction and thermally desorbed (SBSE-TD) before analysis by GC-MS. Several parameters affecting the derivatisation step and both SBSE extraction and thermal desorption were carefully optimised. When the analyses of BHA and TBHQ in their acetylated, silylated and underivatised forms were compared, the best results were obtained when the in-situ derivatisation procedure with acetic anhydride was employed. Quantification was carried out using carvacrol as the internal standard, providing quantification limits of between 0.11 and 0.15 ng ml⁻¹, depending on the compound. Recovery assays for samples spiked at two concentration levels, 1 and 5 ng ml⁻¹, provided recoveries in the 81–117% range. The proposed method was applied in the analysis canned soft drinks and the analytes were found in five of the 10 samples analysed.

Graphical Abstract

Keywords:

• butylated hydroxytoluene (BHT)
• butylated hydroxyanisole (BHA)
• tert-butyl hydroquinone (TBHQ)
• soft drinks
• stir-bar sorptive extraction (SBSE)
• GC-MS

ORCID

Natalia Campillo http://orcid.org/0000-0001-6616-951X

Pilar Viñas http://orcid.org/0000-0001-5219-3711

Manuel Hernández-Córdoba http://orcid.org/0000-0003-1795-3476

Additional information

Funding

The authors acknowledge the financial support of the Comunidad Autónoma de la Región de Murcia [Fundación Séneca, project number 15217/PI/10]. J. I. Cacho also acknowledges a fellowship from the University of Murcia.