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).

Extractive Spectrophotometric Method for the Determination of Glibenclamide by Ion-Pair Complex in Pure Form and Pharmaceutical Formulation

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Pharmaceutical Formulation ◽  
Ratio Method ◽  
Colored Complex ◽  
Colored Product ◽  
Method Of Continuous Variation ◽  
Job's Method

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.

Spectrophotometric Determination of Alendronate Sodium by using Sodium-1,2-Naphthoquinone-4-Sulphonate

2012 ◽  
Vol 4 (4) ◽  
pp. 1563-1568
Author(s):  
Sagar Suman Panda ◽  
Ravi Kumar B V V ◽  
D Patanaik
Keyword(s):  
Spectrophotometric Method ◽  
Absorption Maximum ◽  
Dosage Form ◽  
Dosage Forms ◽  
Alendronate Sodium ◽  
Colored Complex ◽  
Pharmaceutical Dosage Forms ◽  
Recovery Study ◽  
Assay Conditions

A simple, precise and accurate spectrophotometric method was developed for analysis of the osteoporesis drug alendronate sodium (ALS). The method is based on reaction of the drug with sodium-1,2-naphthoquinone-4-sulphonate (NQS) in presence of alkali to form a brown colored complex giving absorption maximum at 525 nm. The drug obeyed Beer’s law in the range of 5-70 µg/ml with a correlation coefficient of 0.999. The LOD and LOQ values are 1.7 µg/ml and 5.0 µg/ml, respectively. The average recoveries for recovery study were found to be in the range of 99.37%-100.46%. The R.S.D. values for intraday and inter-day precision were found to be 0.48 and 0.62, respectively. The optimized assay conditions were applied successfully for determination of ALS in pharmaceutical dosage forms. No interference was observed from the excipients present in the dosage form. The method is statistically validated as per the ICH requirements.  

scholarly journals Polyphenolic compounds and essential oil analysis of selected species of the genus Thymus / Analýza fenolových zložiek a analýza silice vybraných druhov rodu Thymus

2015 ◽  
Vol 62 (s9) ◽  
pp. 12-17
Author(s):  
M. Kameníková ◽  
S. Fialová ◽  
A. Ťažký ◽  
I. Čičová
Keyword(s):  
Phenolic Compounds ◽  
Essential Oil ◽  
Spectrophotometric Method ◽  
Total Phenolics ◽  
Chemical Constituents ◽  
Aluminium Chloride ◽  
Total Phenolic ◽  
Oil Analysis ◽  
European Pharmacopoeia

Abstract The content of phenolic compounds (total phenolic compounds, tannins, flavonoids and anthocyanidins) of three species of thyme (Thymus pulegioides, Thymus pannonicus, Thymus praecox) of different origin (Bohemian-Moravian highlands, Křivoklat and Považsky Inovec) was determined using spectrophotometric methods of European Pharmacopoeia 8th edition. Furthermore, the determination of the content of essential oil and analysis of its constituents was realised. The amount of total phenolics was determined by a spectrophotometric method using the Folin-Ciocalteu reagent. Their content ranged from 3.87 to 8.86%. The content of tannins was established on a preliminary determination of the total phenolics, followed by adsorption of tannins on hide powder. The amount of tannins in our samples varied from 1.96 to 5.65%. The content of total flavonoids was determined by a spectrophotometric method using aluminium chloride. Quantitative analysis of flavonoids has shown that content in our samples ranged from 0.59 to 1.52% expressed as luteolin-7-O-glucoside (λ = 392 nm) and from 0.41 to 1.12% expressed as rutin (λ = 420 nm). Anthocyanins represent a small amount of total polyphenol content in Thymus species. In our samples, the content of anthocyanins expressed as cyanidin-3-O-glucoside varied from 0.02 to 0.1%. The determination of essential oil was realised by method of European Pharmacopoeia 8th edition. Its contents in our samples ranged from 0.2 to 0.75%. Gas chromatography-mass spectrometry was used for essential oil analysis. According to the presence of main monoterpene in Thymus essential oil, we can distinguish three chemotypes: thymol, carvacrol and linalool. Due to variations of chemical constituents of thyme essential oil, it was possible to observe a relationship between occurrence of certain chemotype and origin of sample. Differences in content of flavonoids have not shown a significant relationship to locality of origin.

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 Evaluation of different methodologies for the determination of phenolic compounds in tropical fruits

2020 ◽  
Vol 23 ◽  
Author(s):  
Karina Carvalho Guimarães ◽  
Derlyene Lucas Salgado ◽  
Elisângela Elena Nunes Carvalho
Keyword(s):  
Phenolic Compounds ◽  
Vitamin C ◽  
Fruits And Vegetables ◽  
Titratable Acidity ◽  
Natural Antioxidants ◽  
Soluble Solids ◽  
Total Phenolic ◽  
Fast Blue ◽  
Recent Method

Abstract Phenolic compounds are natural antioxidants and can be found with abundance in fruits and vegetables. One of the first methods created for analyzing phenolic compounds was the Folin-Denis method; and hereafter, the Folin Ciocalteu method was developed and recently, one of the most recent method is the Fast Blue. Due to the importance of these compounds in food, this work aimed to determine the total phenolic compounds in three fruits, such as: Passion Fruit, “Palmer” mango and “Pera” orange. In addition, these fruits were analyzed through three different determination methods. Furthermore, the content of vitamin C, soluble solids, titratable acidity and pH of these fruits were evaluated. Based on the results, it was verified that there was no difference among the values of vitamin C, soluble solids and TA in relation to those found in the literature. When comparing the three methods (Fast Blue BB, Folin-Ciocalteu Reagent and Folin-Denis Reagent), the results showed a difference in the phenolic compounds that may be related to the distinct reagents used in each method and its different action.

Colorimetric Method for Ester Content of Alcoholic Beverages

1971 ◽  
Vol 54 (5) ◽  
pp. 1225-1230
Author(s):  
G R Coe ◽  
S Baldwin ◽  
A A Andreasen
Keyword(s):  
Alkaline Solution ◽  
Hydroxamic Acid ◽  
Colorimetric Method ◽  
Small Sample ◽  
Alcoholic Beverages ◽  
Colored Complex ◽  
Ester Content

Abstract A colorimetric method for determination of esters in alcoholic products was studied for the effect of procedural variables. It is based on the quantitative reaction of esters with hydroxylamine in alkaline solution to form a hydroxamic acid which, upon acidification, forms a colored complex in the presence of Fe(III) ions. Mathematical data are presented to demonstrate that the colorimetric method is superior to the AOAC saponification method, 9.051-9.052, for comparing samples which contain widely differing ester compositions. The colorimetric method is rapid and requires a small sample.

scholarly journals VISIBLE SPECTROPHOTOMETRIC METHOD DEVELOPMENT AND VALIDATION OF IMATINIB IN BULK AND FORMULATION

2020 ◽  
pp. 63-67
Author(s):  
SMITA KUMBHAR ◽  
VINOD MATOLE ◽  
YOGESH THORAT ◽  
ANITA SHEGAONKAR ◽  
AVINASH HOSMANI
Keyword(s):  
Spectrophotometric Method ◽  
Method Development ◽  
Pharmaceutical Formulations ◽  
Uv Spectrum ◽  
Colored Complex ◽  
Pharmaceutical Dosage Forms ◽  
Highly Sensitive ◽  
Method Development And Validation ◽  
Development And Validation

Objective: A new, simple, sensitive, precise and reproducible UV visible spectrophotometric method was developed for the determination of Imatinib in pharmaceutical formulations with alizarin. Methods: The method is based on formation of yellow-colored complex. The UV spectrum of Imatinib in methanol showed λ max at 431 nm. Beer’s law is valid in the concentration range of 10-70 μg/ml. This method was validated for linearity, accuracy, precision, ruggedness and robustness. Results: The method has demonstrated excellent linearity over the range of 10-70 μg/ml with regression equation y =0.013x-0.017 and regression correlation coefficient r2= 0.997. Moreover, the method was found to be highly sensitive with LOD (4.3μg/ml) and LOQ (13.07μg/ml). Conclusion: Based on results the proposed method can be successfully applied for the assay of Imatinib in various pharmaceutical dosage forms.

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 HPLC determination of phenolic compounds content in Parmelia sulcata and Parmelia vagans thalli

Pharmacia ◽  
2019 ◽  
Vol 66 (4) ◽  
pp. 161-164
Author(s):  
O. A. Kyslychenko ◽  
Viktoriia V. Protska ◽  
Iryna O. Zhuravel
Keyword(s):  
Phenolic Compounds ◽  
Inflammatory Diseases ◽  
Raw Materials ◽  
Folk Medicine ◽  
Usnic Acid ◽  
Total Content ◽  
Raw Material ◽  
Parmelia Sulcata ◽  
Quantitative Content

The species of Parmelia genus have long been used in Indian folk medicine for the treatment of bronchitis, ulcers, furunculosis, cardiovascular diseases, urolithiasis, amenorrhea, and also at infectious and inflammatory diseases. In Ukraine, the most common lichens of the Parmelia genus are Parmelia sulcata Tailor and Parmelia vagans Nyl. At the same time, thalli of Parmelia genus lichens belong to the non-officinal and poorly studied types of raw material. The qualitative composition and the quantitative content of phenolic compounds in Parmelia sulcata and Parmelia vagans thalli was studied by HPLC. According to the results of the chromatographic analysis, salazinic, fumaroprotocetraric, usnic acids, chloratranorin and atranorin were identified in both types of raw material studied. In addition, protocetraric acid was identified in Parmelia sulcata thalli. According to the results of the experiment, the total content of identified phenolic compounds in Parmelia sulcata thalli was 2019.71±40.39 g/mol, and in Parmelia vagans thalli it comprised 1754.18±34.77 g/mol. In the thalli of both studied species of Parmelia genus, fumaroprotocetraric acid dominanted by the quantity. This substance was present in Parmelia sulcata thalli in the amount of 474.00±9.00 g/mol, and in Parmelia vagans thalli – 456.21±8.67 g/mol. In addition, a significant amount of chloratranorin (408.79±8.99 g/mol) was present in Parmelia sulcata thalli. Quite a high content of atranorin (393.34±8.65 g/mol) and usnic acid (375.31±7.53 g/mol) were defined in Parmelia vagans thalli. The results obtained can be used in the development of quality control methods for Parmelia sulcata and Parmelia vagans thalli, as well as medicines based on these types of raw materials.

scholarly journals Development of a technology for the production of snacks based on blackcurrant berries (Ribes nigrum)

2019 ◽  
Vol 81 (3) ◽  
pp. 158-167
Author(s):  
N. V. Makarova ◽  
D. F. Ignatova ◽  
E. A. Vasileva ◽  
Y. I. Solina ◽  
E. A. Eliseeva
Keyword(s):  
Vitamin C ◽  
Dietary Fiber ◽  
Total Content ◽  
Titratable Acidity ◽  
Biologically Active ◽  
Total Phenolic ◽  
Organoleptic Characteristics ◽  
Freeze Dried ◽  
Dpph Method ◽  
Phenolic Substances

Interest in the consumption of berries is largely due to the content of biologically active substances in them and their importance as dietary antioxidants. Polyphenolic compounds found in blackcurrant berries are known as agents that act prophylactically and therapeutically on the human body. The following were determined: total content of phenolic substances, flavonoids, anti-radical activity according to the DPPH method, restoring power according to the FRAP method, anthocyanins, organoleptic characteristics, dietary fiber content, vitamin C content for feedstock, semi-finished products (blackcurrant berries, blackcurrant puree, two types freeze-dried snacks from blackcurrant berries). According to the results of the study, it was found that the freeze-dried berry (snacks of two types of freeze-drying) showed good results: 42.05 mmol Fe2 +/1 kg (snacks with a structure-forming agent, 5% pectin), 38.6 mmol Fe2 +/1 kg ( snacks) restoring power according to the FRAP method, 47.1 Ec 50 mg/ml (snacks), 79.4 Ec 50 mg/ml (snacks with a builder, pectin 5%) anti-radical activity according to the DPPH method, 766 mg HA/100 g ( snacks), 835 mg HA/100 g (snacks with a builder, pectin 5%) total phenolic content, 374 mg K/100 g (snacks), 392 mg K/100 g (snacks with by a touring agent, 5% pectin) total flavonoid content, 166.07 mg CG/100 g (snacks), 174.21 mg CG/100 g (snacks with a structuring agent, 5% pectin) anthocyanins content, 50.1% (snacks), 66.9% (snacks with a builder, pectin 5%) vitamin C content, 76.8% (snacks), 90% (snacks with a builder, pectin 5%) dietary fiber, 1.92% (snacks), 2.13 % (snacks with a builder, pectin 5%) – titratable acidity. Thus, we can conclude that vacuum drying provides samples with good physicochemical properties and is better than a dried sample.

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