Determination of Total Carbohydrates in Wine and Wine-Like Beverages by HPLC with a Refractive Index Detector: First Action 2013.12

2014 ◽  
Vol 97 (2) ◽  
pp. 498-505 ◽  
Author(s):  
Steve Kupina ◽  
Mark Roman ◽  
D Anderson ◽  
S Bhandari ◽  
M S Cardozo ◽  
...  
Keyword(s):  
Refractive Index ◽  
Reference Material ◽  
Organic Acids ◽  
Red Wine ◽  
Collaborative Study ◽  
Ion Exchange Resin ◽  
White Wine ◽  
Negative Control ◽  
Total Carbohydrates

Abstract An international collaborative study was conducted of an HPLC-refractive index (RI) detector method for the determination of the combined amounts of sugars, glycerol, organic acids, and phenolic compounds in wines and wine-like beverages. Nine collaboratinglaboratories representing major winery, contract laboratories, and government laboratories tested eight different materials as blind duplicates using the proposed method. Sample materials included red and white wines, port, wine cooler, and nonalcoholic wine. One material was a negative control, and one material was a reference material. Samples were either treated with an ion-exchange resin to remove interferingorganic acids prior to analysis or left untreated toinclude organic acids and phenolics. Red wine samples were treated with polyvinylpolypyrrolidone to remove potential interferences from phenolics prior to analysis. The HPLC analyses were performed on a Bio-Rad Fast Acid Analysis Column using RI detection. Reproducibility (RSDR) for untreated samples(sugars + phenolics + organic acids) ranged from 6.6% for Titrivin AA4 reference material to 11.0% for dry red wine. RSDR for treated samples (sugars only) ranged from 6.8% for white zinfandel to 18.9% for dry white wine. RSDR for treatedsamples (sugars only) + glycerol ranged from 6.4% for white zinfandel to 19.8% for dry red wine. Based on these results, the method was adopted as Official First Action status for determination of total carbohydrates in wine and wine-like beverages.

scholarly journals Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Cleanup and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study

2001 ◽  
Vol 84 (6) ◽  
pp. 1818-1827 ◽  
Author(s):  
Angelo Visconti ◽  
Michelangelo Pascale ◽  
Gianluca Centonze ◽  
E Anklam ◽  
A M Betbeder ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Red Wine ◽  
Collaborative Study ◽  
White Wine ◽  
Fluorometric Detection ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from ≤0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were ≤0.4 for the 3 matrixes.

Determination of Free (pH 2.2) Sulfite in Wines by Flow Injection Analysis: Collaborative Study

1990 ◽  
Vol 73 (2) ◽  
pp. 223-226
Author(s):  
John J Sullivan ◽  
Thomas A Hollingworth ◽  
Marleen M Wekell ◽  
Victor A Meo ◽  
Ali Etemad-Moghadam ◽  
...  
Keyword(s):  
Flow Injection ◽  
Flow Injection Analysis ◽  
Red Wine ◽  
Collaborative Study ◽  
White Wine ◽  
Average Level ◽  
Aoac Official ◽  
Green Solution ◽  
High Degree

Abstract A method for the determination of free sulfite In wine by flow injection analysis (FIA) is described. The method Involves liberation of sulfur dioxide from the wine at pH 2.2, with detection by decolorlzation of a malachite green solution. The method was collaboratively studied, and the results indicated an average reproducibility of 12% for white wine samples (average level 12.1 ppm S02) and 26% for red wine samples (average level 3.1 ppm). When the FIA method was compared to an aeration/oxidation method, the results Indicated a high degree of correlation between the 2 methods. The FIA method has been adopted by AOAC official first action.

Ripper Procedure for Determining Sulfur Dioxide in Wine: Collaborative Study

1980 ◽  
Vol 63 (2) ◽  
pp. 194-199 ◽  
Author(s):  
James M Vahl ◽  
Jean E Converse ◽  
◽  
A A Andreasen ◽  
J H Barnett ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Systematic Error ◽  
Red Wine ◽  
Collaborative Study ◽  
White Wine ◽  
Analysis Of Covariance ◽  
Iodometric Titration ◽  
Laboratory Error ◽  
Large Systematic Error

Abstract Twenty-three laboratories analyzed 5 replicate wine samples according to a specified version of the Ripper direct iodometric titration for sulfur dioxide. Each sample was analyzed for (A) free S02, (B) total S02, and (C) iodine-reactive substances other than S02. Although variations of A with temperature and of A and B with time of analysis were anticipated, analysis of covariance showed no significant reduction in error when these variables were taken into account. Error did vary with S02 level and wine type, red vs white. Pooled estimates of precision (withinlaboratory error) in mg S02/L wine were, for white wine: (A) 3.3, (B) 10.4, (C) 1.9; for red wine: (A) 3.8, (B) 7.3, (C) 1.9. Pooled estimates of systematic (between-laboratory) error in mg SO2/L wine were, for white wine: (A) 2.7, (B) 16.6, (C) 2.1; for red wine: (A) 4.3, (B) 15.1, (C) 3.0. Although rapid and convenient, the Ripper method is severely limited by poor precision and large systematic error. The Ripper method is not recommended for adoption by the AOAC.

Organic Acids in Vanilla Extract

1963 ◽  
Vol 46 (4) ◽  
pp. 626-633 ◽  
Author(s):  
J Fitelson
Keyword(s):  
Organic Acids ◽  
Chromatographic Method ◽  
Exchange Resin ◽  
Collaborative Study ◽  
Gradient Elution ◽  
Ion Exchange Resin ◽  
Elution Pattern ◽  
Check Method ◽  
Elution Method ◽  
Good Agreement

Abstract I. Paper Chromatographic Method Five samples of vanilla extract were submitted for collaborative study. Collaborators reported that the paper chromatographic method was simple and gave considerable information. Comparison with the results obtained by two-dimensional paper chromatography on the same five samples showed good agreement; the organic acid method disclosed adulteration more definitely in some samples. The method was recommended for adoption as official, first action. II. Gradient Elution Method In the Gradient Elution Method, the organic acids are separated from the extract by an ion exchange resin and eluted with increasing concentrations of formic acid. Vanilla extract shows a typical elution pattern with 4 peaks. Results are reported on 87 authentics (54 previously published, 33 new samples). Collaborative study on 4 samples resulted in several modifications. The method was recommended as official, first action as a check method for adulterated samples.

Collaborative Study of the Determination of Soluble Solids in Tomato Products by Refractive Index Expressed as Per Cent Sucrose

1969 ◽  
Vol 52 (5) ◽  
pp. 1050-1054
Author(s):  
Frank C Lamb ◽  
George Evans
Keyword(s):  
Refractive Index ◽  
Enzyme Preparation ◽  
Collaborative Study ◽  
Soluble Solids ◽  
Vacuum Drying ◽  
Equal Weight ◽  
Drying Method ◽  
Filtration Method ◽  
Tomato Products

Abstract A collaborative study was conducted on a method for determining refractive index of tomato concentrates after filtration. A pectic enzyme preparation in dry form is added to undiluted concentrate to facilitate filtration and an optional incubation step is included for samples which are difficult to filter. Dilution with an equal weight of water containing the enzyme preparation is specified for samples which cannot be filtered satisfactorily without dilution. Standard deviations varied from 0.15% for a sample giving a reading of 24% sucrose at 20°C to 0.40% for a sample reading 44%. This agreement is comparable to that previously obtained on the official vacuum drying method. Results are reported from two laboratories using ultracentrifugation methods for obtaining clear serum. It is recommended that the filtration method be adopted as official first action and that the ultracentrifuge method be further studied.

Determination of Organic Acids in Red Wine and Must on Only One RP-LC-Column Directly After Sample Dilution and Filtration

2009 ◽  
Vol 69 (11-12) ◽  
pp. 1391-1395 ◽  
Author(s):  
Yan-Jun Zheng ◽  
Yun-Tao Duan ◽  
Yan-Fang Zhang ◽  
Qiu-Hong Pan ◽  
Jing-Ming Li ◽  
...  
Keyword(s):  
Organic Acids ◽  
Red Wine ◽  
Sample Dilution

scholarly journals Determination of Fluoride in Wine by Fluoride Selective Ion Electrode, Standard Addition Method: Collaborative Study

2003 ◽  
Vol 86 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
Bruno E Trombella ◽  
Arthur Caputi ◽  
Daniel Musso ◽  
Anthony Ribeiro ◽  
Timothy Ryan ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Standard Addition ◽  
The United States ◽  
White Wine ◽  
Addition Method ◽  
Relative Standard ◽  
Standard Deviations ◽  
Study Director ◽  
Statistical Results

Abstract The accuracy, precision, and reproducibility of a rapid method for determination of fluoride in wine, using a fluoride selective ion electrode, were established by a collaborative study involving 12 laboratories, 5 in Europe and 7 in the United States. The laboratories assayed 6 Youden pairs of fluo-ride-fortified, red and white wine samples with fluoride concentrations ranging from 0.2 to 3.0 mg/L. The relative standard deviations of repeatability ranged from 1.94 to 4.88%; relative standard deviations of reproducibility ranged from 4.15 to 18.40%. HORRAT values ranged from 0.30 to 0.97. The average recovery was 99.97%. Based on the statistical results of this collaborative study, the Study Director recommends that this method be adopted First Action.

scholarly journals Determination of Ephedrine Alkaloids in Dietary Supplements and Botanicals by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study

2003 ◽  
Vol 86 (4) ◽  
pp. 657-668 ◽  
Author(s):  
William A Trujillo ◽  
Wendy R Sorenson ◽  
J Laurensen ◽  
G Luo ◽  
R McClanahan ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Collaborative Study ◽  
Internal Standard ◽  
Negative Control ◽  
Interlaboratory Study ◽  
Tandem Mass ◽  
Accuracy And Precision ◽  
Ephedra Nevadensis

Abstract An interlaboratory study was conducted to evaluate the accuracy and precision of a method for ephedrine-type alkaloids [i.e., norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME), and methylpseudoephedrine (MPE)] in dietary supplements and botanicals. The amount of ephedrine-type alkaloids present was determined using liquid chromatography with tandem mass selective detection. The samples were diluted to reflect a concentration of 0.0200 to 1.00 μg/mL for each alkaloid. An internal standard was added and the alkaloids were separated using a 5 μm phenyl LC column with an ammonium acetate, glacial acetic acid, acetonitrile, and water mobile phase. Eight blind duplicates of dietary supplements or botanicals were analyzed by 10 collaborators. Included was a negative control, ephedra nevadensis, and negative controls fortified at 2 different levels with each of the 6 ephedrine-type alkaloids. The spike levels were approximately 100 and 1000 μg/g for NE, 100 and 600 μg/g for NPE, 6500 and 65 000 μg/g for E, 1000 and 10 000 μg/g for PE, 300 and 3000 μg/g for ME, and 100 and 1000 μg/g for MPE. On the basis of the accuracy and precision results for this interlaboratory study, it is recommended that this method be adopted Official First Action for the determination of 6 different individual ephedrine-type alkaloids in dietary supplements and botanicals.

Determination of Carbohydrates in Soluble Coffee by Anion-Exchange Chromatography with Pulsed Amperometric Detection: Interlaboratory Study

1995 ◽  
Vol 78 (3) ◽  
pp. 768-782 ◽  
Author(s):  
Jacques Prodolleet ◽  
Emmanuel Bugner ◽  
Max Feevberg
Keyword(s):  
Anion Exchange ◽  
Pure Water ◽  
Collaborative Study ◽  
Amperometric Detection ◽  
Exchange Chromatography ◽  
Anion Exchange Column ◽  
Relative Standard ◽  
Total Carbohydrates ◽  
Soluble Coffee

Abstract A collaborative study was conducted to validate a liquid chromatographic (LC) method to determine the free and total (after acid hydrolysis) carbohydrate profile of soluble coffee. Carbohydrates were separated on a pellicular anion-exchange column using pure water as mobile phase, and were detected by pulsed amperometry. Eleven collaborators were sent 6 test samples of commercial soluble coffee for duplicate analysis. They were also sent a practice sample with known levels of free and total carbohydrates and material for preparation of all standard solutions. The reproducibility relative standard deviations (RSDR) were 9.9–59.5% for mannitol, 35.6–72.6% for fucose, 4.9–21.1% for arabinose, 4.1–13.0% for galactose, 6.1–24.3% for glucose, 10.0–41.6% for sucrose, 20.2–37.7% for xylose, 10.6–40.0% for mannose, 15.5–71.7% for fructose, and 17.8–97.9% for ribose. Precision in the determination of free and total carbohydrates was very similar. The average repeatability RSDr and RSDR values were 4.5 and 14.3%, respectively, for carbohydrate levels above 0.3%. The precision of the technique was considered good, regardless of the usual peak integration problems always encountered in LC, the low levels of free carbohydrates, the hydrolysis step, and the relative lack of experience of most participating laboratories. The method allows good and reproducible separation of all major carbohydrates found in soluble coffee and is, therefore, suitable for routine analysis.

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