The true pinnacle of precision and quality

Guaranteed 0.5ng/L, backed up by Science

The Vocus Cork Analyzer quantitatively measures TCA levels below the sensory threshold in individual corks in just a few seconds.

CORK SPECTRA IS COMPLEX

2,4,6-Trichloroanisole (TCA) is a tiny fraction of the total volatile compounds (VOCs) emission from a cork. In 1994, a study published by the American Journal of Enology and Viticulture (Vol. 45, No. 4) listed as many as 107 compounds. 

MASTERING VOCs EXTRACTION VIA THERMAL DESORPTION

With the ultimate goal of extracting all VOCs, corks are preheated in a custom oven for 25 minutes at 120°C and under laminar flow to avoid contamination and maximize extraction. During this phase, the headspace measurement is dynamic and three internal standards are continuously added for mass and sensitivity calibration.

IDENTIFICATION OF TCA IS UNAMBIGUOUS

VOCs are ionized with reagent ions, extracted into time-of-flight (TOF) mass spectrometer and separated by mass-to-charge ratio. The separation is exact and based on the isotopic mass of 2,4,6-Trichloroanisole (TCA). With 3 exact masses and 2 isotopic ratios there are 5 channels of unambiguous identification thus excluding the presence of false negatives or positives.

LINEAR QUANTITATIVE RESPONSE

The intensity of the signal is directly proportional to TCA concentration, enabling accurate determination of TCA levels. In a first-of-its-kind breakthrough, Vocus shows a linear correlation with the standard ISO 20752 also known as Releasable TCA or RTCA(1). These findings have been published and validated by the Peer Review Journal, Analytical Chemistry published by the American Chemical Society (2).

(1) Herve, E.; Price, S.; Burns, G.; Weber, P. TCA in corks, cork soaks and bottled wine. ASEV Annual Meeting, Reno, NV, 1999 (2)https://pubs.acs.org/doi/10.1021/acs.analchem.0c01326

Source: TOFWERK AG

SENSITIVITY MATTERS

Individual corks are measured sequentially by online mass spectrometry. A unique TCA measurement is made every 100 ms, and averaged to quantify the TCA content in each cork. The VOCUS technology with a Limit of Detection (LOD) of 0.03 ng/L and Limit of Quantification (LOQ) of 0.10 ng/L has a sensitivity rate at least five times higher than other methods.

Source: TOFWERK AG

REPEATABILITY AT LOW CONCENTRATION

A set of cork stoppers having a wide range of TCA concentrations was measured thirteen times, with three weeks in between measurements. The measured concentrations for each cork were consistent across all the successive measurements.

Source: TOFWERK AG

SIMULTANEOUS MULTI-TARGET TOF-MS ANALYSIS

The Vocus Cork Analyzer simultaneously quantifies not only TCA but also other haloanisoles and their phenolic precursors below perception threshold in 3 seconds. Only a TOF-MS is capable of screening for different halonisoles simultaneously thus assuring complete neutrality of the corks delivered.

Source: TOFWERK AG