Cyclic voltammetry: A tool to quantify 2,4,6-trichloroanisole in aqueous samples from cork planks boiling industrial process

Abstract

Chloroanisoles, namely 2,4,6-trichloroanisole, are pointed out as the primary responsible of the 27 development of musty off-flavours in bottled wine, due to their migration from cork stoppers, which 28 results in huge economical losses for wine industry. A prevention step is the detection of these 29 compounds in cork planks before stoppers are produced. Mass spectrometry gas chromatography is 30 the reference method used although it is far beyond economical possibilities of the majority of cork 31 stoppers producers. In this work, a portable cyclic voltammetry approach was used to detect 2,4,6-32 trichloroanisole extracted from natural cork planks to the aqueous phase during the cork boiling 33 industrial treatment process. Analyses were carried out under ambient conditions, in less than 15 34 minutes with a low use of solvent and without any sample pre-treatment. The proposed technique 35 had detection (0.31±0.01 ng/L) and quantification (0.95±0.05 ng/L) limits lower than the human 36 threshold detection level. For blank solutions, without 2,4,6-trichloroanisole addition, a 37 concentration in the order of the quantification limit was estimated (1.0±0.2 ng/L), which confirms 38 the satisfactory performance of the proposed methodology. For aqueous samples from the industrial 39 cork planks boiling procedure, intra-day repeatabilities were lower than 3%, respectively. Also, 40 2,4,6-trichloroanisole contents in the aqueous samples determined by this novel approach were in 41 good agreement with those obtained by GC-MS (correlation coefficient equal to 0.98), confirming 42 the satisfactory accuracy of the proposed methodology. So, since this novel approach is as fast, low-43 cost, portable and user-friendly method, it can be an alternative and helpful tool for in-situ industrial 44 applications, allowing accurate detection of releasable 2,4,6-trichloroanisole in an earlier phase of 45 cork stoppers production, which may allow implementing more effective cork treatments to reduce 46 or avoid future 2,4,6-trichloroanisole contaminations of wine. 47 48

Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS

“…Other techniques for the extraction of aldehydes and other VOCs have been used in cork- and wood-based samples, such as solid-phase microextraction, − dynamic headspace, , and simultaneous distillation and extraction . Although the most common analytical techniques used are spectrophotometry, , liquid chromatography, , and gas chromatography, ,,, other techniques such as cyclic voltammetry have successfully been used for the analysis of VOCs in cork- and wood-based samples.…”

Biosensor-Based Approaches for Detecting Ochratoxin A and 2,4,6-Trichloroanisole in Beverages

“…In the framework of this proof-of-concept study, an LOD of 200 µg L −1 of TCA and good discrimination against the interferant TCP were achieved. Finally, Peres et al [78,79] reported the use of cyclic voltammetry (CV) for determination of TCA in aqueous cork extracts, resulting from the immersion of cork planks in boiling water (60 min), which is a standard component of commercial cork processing. Tetrabutylammonium perchlorate (TBAP, 0.1 M) was used as the supporting electrolyte in order to increase current intensity.…”

Comparative Study of a Cell-Based and Electrochemical Biosensor for the Rapid Detection of 2,4,6-Trichloroanisole in Barrel Water Extracts

“…The aqueous samples provided were used after being diluted with either MeOH or ACN containing 0.17 M TBAP, in order to obtain a volumetric proportion of 1:1 or 3:2 and a final solution with 0.1 M TBAP. The 2,4,6-TCA concentrations, before and after standard solution addition were calculated by using a similar procedure as that described in the previous section for ACN/water solutions, but taking into account the standard addition calibration method with volume correction, due to the dilution factor [20]. Thus, a linear relationship was established between the total current amplitude multiplied by the final volume after each addition of the standard solution and the total added volume of the standard 2,4,6-TCA in ACN/water with 0.1 M of TBAP.…”