Development of a Gas Diffusion Multicommuted Flow Injection System for the Determination of Sulfur Dioxide in Wines, Comparing Malachite Green and Pararosaniline Chemistries

Abstract

A flow system based on the multicommutation concept was developed for the determination of free and total sulfur dioxide in table wines, exploiting gas diffusion separation and spectrophotometric detection. The system allowed the comparison of malachite green and pararosaniline chemistries, using the same manifold configuration. Free and total SO(2) were determined within the ranges 1.00-40.0 and 25.0-250 mg L(-1), at determination throughputs of 25 and 23 h(-1), respectively. Employing the malachite green reaction, detection limits of 0.3 and 0.8 mg L(-1) were attained for free and total SO(2), respectively. Pararosaniline chemistry provided detection limits of 0.6 mg L(-1) for free SO(2) and 0.8 mg L(-1) for total SO(2). Relative standard deviations better than 1.8 and 1.4% were obtained by the malachite green and pararosaniline reactions, respectively. With regard to the two tested chemistries, 18 wines were analyzed and the results achieved by the pararosaniline reaction compared better with those furnished by the recommended procedure.

Scientific Opinion on the evaluation of allergenic foods and food ingredients for labelling purposes

“…A GD multicommuted FIA for the determination of free and total sulphites in white and red wine has been reported (Oliveira et al, 2009). The methodology is based on two spectrophotometric reactions with malachite green (MG) and para-rosaniline (PRA), with no previous treatment of the sample.…”

To the question about the definition of a stationary temperature field in the capillary during the passage of electric current and the change in water concentration of impurities in the temperature field

“…В частности широкое применение нашел метод газовой диффузии. Разработаны системы ПИА [44][45][46][47][48][49][50][51] и SIA [52][53][54][55], включающие проточные ячейки для выделения аналитов методом газовой диффузии в сочетании с их последующим детектированием любым из подходящих для этого методов. Схема анализа в таких системах основана на том, что газообразные аналиты, изначально присутствующие в объектах анализа (О 2 , О 3 , С1 2 ), или газообразные соединения, образующиеся в результате химических реакциий в потоке (SO 2 , СО 2 , NH 3 , H 2 S, H 2 Se и др.…”

Optimization of Working Conditions by Response Surface Methodology of Sulfur Dioxide Gas Sensors Based on Au/CoO‐2La2WO6 Nanoparticles

“…There are many methods to measure sulfur dioxide in the laboratory, such as spectrophotometry, colorimetry, titration, electrochemistry, chromatography, atomic fluorescence, mass spectrometry, chemiluminescence (CL), absorption spectrometry, and so on. Operating the methods above is very complicated since they require not only collection and preparation of samples, but also large‐scale analytical instruments.…”