Flow analysis with membrane separation and time based sampling for ethanol determination in beer and wine

Mohns, Jochen; Künnecke, Wolfgang

doi:10.1016/0003-2670(94)00608-o

Cited by 36 publications

(16 citation statements)

References 22 publications

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“…In the case of traditional nano/micropores (Fig.1a), gases will flow through passively regardless of 2 pore shape and surface chemistry, while liquids will enter the pore once the applied pressure reaches a critical value dictated by the balance of surface interactions, pore geometry and surface tension. [21][22][23] If pores are filled with a strongly wetting liquid that completely seals the pore and forms a contiguous coating along the adjacent surface (Fig.1b), gases and liquids must deform the surface of this liquid to enter the pore and will require different pressure thresholds to do so. As long as the pore liquid's affinity for the solid is stronger than that of the transport substance, the pore liquid will part to form an open, fluid-lined pathway while remaining adherent to the pore walls and adjacent surface so that the transport substance, as long as it is immiscible, will not contact any solid surfaces.…”

mentioning

confidence: 99%

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

Hou

Grinthal

et al. 2015

Nature

423

395

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Living organisms make extensive use of micro-and nanometer-sized pores as gatekeepers for controlling the movement of fluids, vapors and solids between complex environments. The ability of such pores to coordinate multiphase transport, in a highly selective and subtly triggered fashion and without clogging, has inspired interest in synthetic gated pores for applications ranging from fluid processing to 3D printing and labon-chip systems 1,2,3,4,5,6,7,8,9,10 . But although specific gating and transport behaviors have been realized by precisely tailoring pore surface chemistries and pore geometries 6,11-17 , a single system capable of selectively handling and controlling complex multiphase transport has remained a distant prospect, and fouling is nearly inevitable 11,12 . Here, we introduce a gating mechanism that uses a capillary-stabilized fluid to seal pores in the closed state, and reversibly and rapidly reconfigures it under pressure to create a non-fouling, fluid-lined pore in the open state. Theoretical modeling and experiments demonstrate that for each transport substance, the gating threshold -the pressure needed to open pores -can be rationally tuned over a wide pressure range. This allows us to realize in one system differential response profiles for a variety of liquids and gases, even letting liquids flow through the pore while preventing gas escape. These capabilities allow us to dynamically modulate gas/liquid sorting in a microfluidic flow and to separate a three-phase air/water/oil mixture, with the fluid lining ensuring sustained antifouling behavior. Because the liquid gating strategy enables efficient long-term operation and can be applied to a variety of pore structures, membrane materials and micro-as well as macro-scale fluid systems, we expect it to prove useful in a wide range of applications.Our hypothesis that a liquid-filled pore could provide a unified gating strategy derives from the idea that a liquid stabilized inside a micropore offers a unique combination of dynamic and interfacial behaviors, and is inspired by nature's use of fluids as reconfigurable gates. Microscale stomata and xylem control air, water, and microbe exchange in plants by using fluid to mechanically reconfigure the pore 18 . The nuclear pore is directly lined with disordered fluidlike proteins that have been proposed not only to regulate differential transport of a wide range of cargos, but also to completely prevent fouling 19 . Most interestingly, micropores between air sacs in the lung are filled with liquid that has been proposed to reversibly reconfigure into an open, fluid-lined pore in response to pressure gradients 20 . Figure 1 contrasts the gating mechanisms in a traditional and in a liquid-filled pore. In the case of traditional nano/micropores (Fig.1a), gases will flow through passively regardless of 2 pore shape and surface chemistry, while liquids will enter the pore once the applied pressure reaches a critical value dictated by the balance of surface interactions, pore geometry and surface tension....

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mentioning

confidence: 99%

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

Hou

Grinthal

et al. 2015

Nature

423

395

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“…In this way, the ethanol contained in the sample passed through the membrane and was swept along by the carrier solution to the flow cell. This type of gas diffusion system was described previously for the analysis of wine and beer [16,17,22], as well as for the determination of ethanol in sweat [29].…”

Section: Optimization Of Parameters Involved In the Construction Of Tmentioning

confidence: 99%

“…Of particular interest are methods based on flow analysis techniques due to their capability to provide short response times and being comparatively easy to automate and miniaturize [9]. Several analytical systems have been implemented using different instrumental techniques, including infrared spectroscopy [10][11][12][13]; visible spectroscopy [14][15][16][17]; nuclear magnetic resonance [18]; mass spectrometry [19]; flame ionization detector (FID) [20]; and biosensor devices involving both optical [21] and electrochemical detection [22][23][24][25][26][27]. Such systems, the main characteristics of which are summarized in Table 1, are likely to be automated and implemented as on-line analyzer systems, making possible to carry out the monitoring of alcohol concentration continuously and in real time.…”

Section: Introductionmentioning

confidence: 99%

Automated Bioanalyzer Based on Amperometric Enzymatic Biosensors for the Determination of Ethanol in Low-Alcohol Beers

et al. 2017

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Abstract:In this work, a new automated bioanalyzer based on the use of enzymatic biosensors as amperometric detectors is reported. This automatic bioanalyzer is configurable both as continuous flow and flow injection analysis systems and enables both on-line and off-line monitoring of ethanol in low-alcohol beer to be performed. The attractive analytical and operational characteristics demonstrated by the automated bioanalyzer make it a promising, simple, rapid, and reliable tool for quality control of this beverage in the beer industry, either during the manufacturing process or in the final product. Moreover its applicability to the analysis of the ethanol content in different non-alcoholic beers working at different modes was successfully demonstrated.

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“…The flow injection methods for determination of ethanol developed so far can be divided mainly into three types according to the derivatization step: enzymatic methods (Wangsa and Danielson, 1991;Kuennecke and Schmid, 1990;Mattos et al, 1995;Xie et al, 1992;Rangel and Toth, 2000) [using alcohol dehydrogenase (EC 1.1.1.1) or alcohol oxidase (EC 1.1.3.13)], redox methods based on oxidation of ethanol with dichromate in acid medium (Mattos et al, 1998;Polo et al, 1986;Mataix and Luque de Castro, 2000a), and those in which no derivatization is required (Chen et al, 1997;Mataix and Luque de Castro, 2000b;González-Rodríguez et al, 2003). In general, the separation techniques used, if necessary, are gas diffusion (Mattos et al, 1998;Polo et al, 1986;Mohns and Kuennecke, 1995;Kuennecke and Schmid, 1990) or pervaporation (Delgado-Reyes et al, 1998; Maitaix and Luque de Castro, 2000b;González-Rodríguez et al, 2003). The usual detection techniques are spectroscopic (photometry or fluorimetry) and electrochemical (amperometry or potentiometry).…”

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confidence: 99%

Analytical Methods in Wineries: Is It Time to Change?

Castro

Pérez-Juan²

2005

Food Reviews International

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A review of the methods for the most common parameters determined in wine-namely, ethanol, sulfur dioxide, reducing sugars, polyphenols, organic acids, total and volatile acidity, iron, soluble solids, pH, and color-reported in the last 10 years is presented here. The definition of the given parameter, official and usual methods in wineries appear at the beginning of each section, followed by the methods reported in the last decade divided into discontinuous and continuous methods, the latter also are grouped in nonchromatographic and chromatographic methods because of the typical characteristics of each subgroup. A critical comparison between continuous and discontinuous methods for the given parameter ends each section. Tables summarizing the features of the methods and a conclusions section may help users to select the most appropriate method and also to know the state-of-the-art of analytical methods in this area. Keywords Parameters, Official methods, Usual methods, Non chromatographic methods, Chromatographic methodsWine is a product with a very complex composition. Among the large number of substances found in wine, many are at very low concentrations even though they play a main role in wine characteristics, evolution, and/or quality. A complete analysis of wine is a time-consuming process, but it yields the necessary information for both elaboration of a quality product and conservation under proper conditions. Usually, the number of parameters to be analyzed is simplified as a function of the aim, the commonest being either to know the evolution of the process or to fulfill food laws. The more detailed the analysis is, the better knowledge of the wine is achieved, but a compromise between time and information requirements must be established in order to guarantee a given quality with minimum cost. Therefore, only a few parameters are periodically checked. Between them, the most common are: soluble solids, reducing sugars, alcoholic degree, pH, total and volatile acidity, sulfur dioxide, color, polyphenol index, iron, and organic acids.Most analytical methods for monitoring wine composition recognized by the international community as official methods of analysis are manual methods with high robustness and precision, even though more recent methods may be based on modern automated instrumental techniques. Nevertheless, the manual methods are slow, tedious, and require a high level of human participation. Thus, their application is a balance between the number of parameters required for monitoring wine production, frequency of analysis, and cost of human and material resources. The new faster methods, which usually have the appropriate sensitivity, selectivity, and precision, can circumvent the problem created by the large number of samples to be analyzed in order to guarantee proper monitoring of wine production. In the last 10 years, rapid and high sample throughput methods of analysis have been developed. It is interesting to know the features of these new methods-mainly in terms of accuracy and preci...

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Flow analysis with membrane separation and time based sampling for ethanol determination in beer and wine

Cited by 36 publications

References 22 publications

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

Liquid-based gating mechanism with tunable multiphase selectivity and antifouling behaviour

Automated Bioanalyzer Based on Amperometric Enzymatic Biosensors for the Determination of Ethanol in Low-Alcohol Beers

Analytical Methods in Wineries: Is It Time to Change?

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