scholarly journals Determination of titratable acidity in white wine

2007 ◽  
Vol 52 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Milos Rajkovic ◽  
Ivana Novakovic ◽  
Aleksandar Petrovic
Keyword(s):  
Tartaric Acid ◽  
Potentiometric Titration ◽  
Ph Value ◽  
Titratable Acidity ◽  
White Wine ◽  
Selective Electrode ◽  
Alcohol Fermentation ◽  
Standard Methods ◽  
Illegal Acts

The amount of titration acid in must is in the largest number of cases with in the range 5.0-8.0 g/dm3. Wines, as a rule, contain less acids than must, and according to Regulations, titratable acidity is in the range of 4.0-8.0 g/dm3 expressed in tartaric acid, because a part of tartaric acid is deposited in the form of salts (tartar or argol) during alcohol fermentation. For wines that contain less than 4 g/dm3 of titratable acids there arises a suspicion about their origin, that is, that during the preparation some illegal acts were done. Because of that, the aim of this paper is to determine titratable acidity in white wine, using standard methods of determination, which are compared with the results received by potentiometric titration using ion-selective electrode. According to the received results it can be seen that wine titration with indicator gives sufficient reliable values of wine titration acidity. However, as potentiometric titration at pH value 7.00 is more reliable and objective method, the values of titratable acids content in wine, expressed through tartaric acid, are given according to this result. The analysis of differential potentiometric curves shows that these curves can give us an answer to the question of the presence of a larger amount of other nonorganic substances, which have already existed in wine. However, none of the used methods gives absolutely reliable answer what substances are present in analysed samples.

scholarly journals Changes of organic acids and phenolic compounds contents in grapevine berries during their ripening

2013 ◽  
Vol 11 (10) ◽  
pp. 1575-1582 ◽  
Author(s):  
Irena Jančářová ◽  
Luděk Jančář ◽  
Alice Náplavová ◽  
Vlastimil Kubáň
Keyword(s):  
Phenolic Compounds ◽  
Tartaric Acid ◽  
Alkaline Solution ◽  
Spectrophotometric Method ◽  
Total Content ◽  
Titratable Acidity ◽  
Colored Complex ◽  
Total Titratable Acidity ◽  
Phenolic Substances

AbstractChanges of total content of phenolic substances, alteration in total titratable acidity and differences in tartaric acid content in grapes of four white (Müller-Thurgau — MT, Pinot Blanc — Rulandské bílé in Czech, RB, Sauvignon (Sg), and Muscat Ottonel — Muškát Ottonel in Czech, MO) and two blue (Dornfelder — Df and Blue Frankish — Frankovka in Czech, Fr) grapevine varieties throughout their growth, ripening and maturing (July–November). Potentiometric titration was applied for the determination of total titratable acids in grapes (expressed as tartaric acid equivalents in g L−1). A spectrophotometric method according Rebelein based on the formation of a colored complex of ammonium metavanadate and tartaric acid was used for determination of tartaric acid in green juice made by pressing unripe grapes. A spectrophotometric method based on reduction of phosphomolybdato-tungsten complex in alkaline solution using Folin-Ciocalteau reagent was applied for determination of total content of phenolic substances (TCP).

Determination of Citrate Ions by Potentiometric Titration with a Copper-Selective Electrode in Monitoring the Production of Citric Acid

2004 ◽  
Vol 59 (3) ◽  
pp. 291-295 ◽  
Author(s):  
L. F. Naumenko ◽  
N. M. Buneeva ◽  
R. N. Korneeva ◽  
V. F. Selemenev ◽  
D. V. Nemtsev
Keyword(s):  
Citric Acid ◽  
Potentiometric Titration ◽  
Selective Electrode ◽  
Citrate Ions

Sequential determination of titratable acidity and tartaric acid in wines by flow injection spectrophotometry

The Analyst ◽  
1998 ◽  
Vol 123 (4) ◽  
pp. 661-664 ◽  
Author(s):  
Antoacute;nio O. S. S. Rangel ◽  
Ildikoacute; V. Toacute;th
Keyword(s):  
Tartaric Acid ◽  
Flow Injection ◽  
Titratable Acidity ◽  
Sequential Determination

scholarly journals Cobalt(II) ion-selective electrode with solid contact

2008 ◽  
Vol 6 (4) ◽  
pp. 607-612 ◽  
Author(s):  
Cecylia Wardak
Keyword(s):  
Detection Limit ◽  
Response Time ◽  
Potentiometric Titration ◽  
Indicator Electrode ◽  
Solid Contact ◽  
Selective Electrode ◽  
Cobalt Ions ◽  
Real Samples ◽  
Nernstian Slope

AbstractA new all plastic sensor for Co2+ ions based on 2-amino-5 (hydroxynaphtyloazo-1′)-1,3,4 thiadiazole (ATIDAN) as ionophore was prepared. The electrode exhibits a low detection limit of 1.5 × 10−6 mol L−1 and almost theoretical Nernstian slope in the activity range 4.0 × 10−6–1 × 10−1 mol L−1 of cobalt ions. The response time of the sensor is less than 10 s and it can be used over a period of 6 months without any measurable divergence in potential. The proposed sensor shows a fairly good selectivity for Co(II) over other metal ions. The electrode was successfully applied for determination of Co2+ in real samples and as an indicator electrode in potentiometric titration of Co2+ ions with EDTA.

Determination of Ammoniacal and Total Nitrogen in Fertilizers by Ammonia-Selective Electrode

1984 ◽  
Vol 67 (5) ◽  
pp. 890-892
Author(s):  
Roberto A Navarro ◽  
Pedro Rojas
Keyword(s):  
Tartaric Acid ◽  
Magnesium Oxide ◽  
Total Nitrogen ◽  
Ammoniacal Nitrogen ◽  
Selective Electrode ◽  
Digestion Procedure ◽  
Acid Recovery ◽  
Aoac Official ◽  
Good For

Abstract A method was studied for determining ammoniacal nitrogen in fertilizers by using an ammonia-selective electrode. Recovery for the method was evaluated with synthetic samples, and the method was also compared with the magnesium oxide method by analyzing 3 Magruder Check Samples. The method was adapted to determine total nitrogen in fertilizers by using the digestion procedure of the modified comprehensive nitrogen method and eliminating metal interferences by forming soluble complexes with tartaric acid. Recovery was evaluated and a comparison with AOAC official methods was made by performing a /-test on results for 3 Magruder Check Samples. Recoveries were good for determinations of both ammoniacal and total nitrogen by the method described, and results were not significantly different from those for AOAC methods.

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