Cyclic voltammetry: A tool to quantify 2,4,6-trichloroanisole in aqueous samples from cork planks boiling industrial process António M. Peres a,b,n , Patrícia Freitas c , Luís G. Dias b , Mara E.B.C. Sousa b , Luís M. Castro c,d , Ana C.A. Veloso c,e a LSRE—Laboratory of Separation and Reaction Engineering—Associate Laboratory LSRE/LCM, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal b CIMO—Mountain Research Centre, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal c Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra, Portugal d GERSE–DCE/FST, Group on Environment, Reaction and Separation Engineering, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Rua Sílvio Lima, Pólo II, 3030-790 Coimbra, Portugal e IBB, Institute for Biotechnology and Bioengineering, Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal article info Article history: Received 19 June 2013 Received in revised form 17 September 2013 Accepted 20 September 2013 Available online 25 September 2013 Keywords: 2,4,6-trichloroanisole Cork Cyclic voltammetry Standard addition method abstract Chloroanisoles, namely 2,4,6-trichloroanisole, are pointed out as the primary responsible of the development of musty off-flavours in bottled wine, due to their migration from cork stoppers, which results in huge economical losses for wine industry. A prevention step is the detection of these compounds in cork planks before stoppers are produced. Mass spectrometry gas chromatography is the reference method used although it is far beyond economical possibilities of the majority of cork stoppers producers. In this work, a portable cyclic voltammetry approach was used to detect 2,4,6-trichloroanisole extracted from natural cork planks to the aqueous phase during the cork boiling industrial treatment process. Analyses were carried out under ambient conditions, in less than 15 min with a low use of solvent and without any sample pre-treatment. The proposed technique had detection (0.31 70.01 ng/L) and quantification (0.95 70.05 ng/L) limits lower than the human threshold detection level. For blank solutions, without 2,4,6-trichloroanisole addition, a concentration in the order of the quantification limit was estimated (1.0 70.2 ng/L), which confirms the satisfactory performance of the proposed methodo- logy. For aqueous samples from the industrial cork planks boiling procedure, intra-day repeatabilities were lower than 3%, respectively. Also, 2,4,6-trichloroanisole contents in the aqueous samples determined by this novel approach were in good agreement with those obtained by GC–MS (correlation coefficient equal to 0.98), confirming the satisfactory accuracy of the proposed methodology. So, since this novel approach is a fast, low-cost, portable and user-friendly method, it can be an alternative and helpful tool for in-situ industrial applications, allowing accurate detection of releasable 2,4,6-trichloro- anisole in an earlier phase of cork stoppers production, which may allow implementing more effective cork treatments to reduce or avoid future 2,4,6-trichloroanisole contaminations of wine. & 2013 Elsevier B.V. All rights reserved. 1. Introduction Wine contamination with fungal aromas is a major problem for the wine industry, namely the organoleptic defect usually (and erroneously) designated as cork taint [1]. Although other sources of contamination exist [1,2] cork is pointed out as its main cause, since cork stoppers would be the source of wine contamination by chloroanisoles, specially 2,4,6-trichloroanisole (2,4,6-TCA), that confers a very unpleasant fungal aroma to the wine even at concentrations of 2–4 ng/L [3]. Different detection (1.4–4.6 ng/L) and recognition thresholds (4.2–10 ng/L) have been reported [3]. The former can be defined as the minimum value of a sensory stimulus needed to give rise to a sensation and the latter as the minimum value of a sensory stimulus permitting identification of the sensation perceived [1]. However, other chemical compounds, like 2,4,6-tribromoanisole, 2-methoxy-3,5-dimethylpyrazine, geosmine, guaiacol, 1-octen-3-one, 1-octen-3-ol or 2-methyl-isoborneol, are also able to taint the wine with fungal off-odours [4,5]. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/talanta Talanta 0039-9140/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.talanta.2013.09.039 n Corresponding author at: LSRE—Laboratory of Separation and Reaction Engineering—Associate Laboratory LSRE/LCM, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal. Tel.: þ351 273303220; fax: þ351 273325405. E-mail address: peres@ipb.pt (A.M. Peres). Talanta 117 (2013) 438–444