scholarly journals Analytical profiling and structure elucidation of flavanoids compounds

2019 ◽  
pp. 7-12
Author(s):  
Rajni Singh Khureja ◽  
Dinesh Kumar
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Ethyl Acetate ◽  
Structure Elucidation ◽  
Uv Light ◽  
Methyl Ethyl ◽  
Aerial Parts ◽  
Acetate Methyl ◽  
Layer Chromatography

Chromatography is a powerful analytical method suitable for the separation and quantitative determination of a considerable number of compounds, even from complicated matrix. Thin Layer Chromatography (TLC) has some advantages such as rapidity, sensitivity, easiness, cheapness and this method does not require complex instrumental equipment. In present study, Quercetin 3 -O -α- d- glucuro pyranoside (miquelianin; QG), quercetin 3-O-α-d glucopyranoside (isoquercitrin), quercetin 3-O-α-d-galactopyranoside (hyperoside) and rutin in ethyl acetate fractions from aerial parts of selected Potentilla species on a HPTLC plates using a mixture consisting of ethyl acetate/methyl ethyl ketone/diisopropyl ether/formic acid (3:10:4:1, v/v/v/v). Rutinosides and quercetin were also eluted using methanol-water-acetic acid (50/44/6, v/v/v) and benzene: pyridine: formic acid (36:9:5). The spot visualization was evaluated under UV light at 254 nm and Ferric chloride reagent.

scholarly journals Determination of Rosmarinic Acid and Caffeic Acid in Thymus daenensis and Thymus lancifolius Extracts by High-Performance Thin Layer Chromatography

2021 ◽  
Vol 10 (4) ◽  
pp. 2804-2809
Keyword(s):  
Thin Layer ◽  
Formic Acid ◽  
Ethyl Acetate ◽  
Thin Layer Chromatography ◽  
Caffeic Acid ◽  
Rosmarinic Acid ◽  
Mobile Phase ◽  
High Performance ◽  
Layer Chromatography

Thymus species belong to the Lamiaceae family, of which 18 species in the flora of Iran, 6 are endemic to Iran. In the current research, high-performance thin-layer chromatography (HPTLC) technique as an easy, fast, reproducible, and low-cost method was used for the determination of rosmarinic acid and caffeic acid in Thymus lancifolius (T. lancifolius) and two species of Thymus daenensis (T. daenensis) from Iran. Toluene-ethyl acetate-formic acid with a ratio of 67.72-22.90 and 9.38% was selected as the mobile phase of rosmarinic acid, and ethyl acetate-methanol-formic acid-water with a ratio of 85-8-2 and 5% was designated as the mobile phase of caffeic acid. The highest and lowest amount of rosmarinic acid was observed for T. daenensis 1 (10.54±0.12 mg/g) and T. lancifolius (0.46±0.01 mg/g), respectively. The amount of rosmarinic acid for T. daenensis 2 was obtained as 7.85±0.02 mg/g for each of the dried plants. In the following, HPTLC analysis of caffeic acid for T. daenensis 1, T. daenensis 2, and T. lancifolius was acquired amounts of 0.78±0.007, 0.13±0.007, and 0.26±0.007 mg/g for each of dried plants, respectively. Therefore, regarding the special effects of phenolic acids and properties of the Thymus genus, the acquired results are suitable for application in pathogenic research, infections, immunology diseases, and evaluation of the antioxidant activity.

Thin Layer Chromatographic Determination of Aflatoxin in Corn Dust

1981 ◽  
Vol 64 (5) ◽  
pp. 1060-1063 ◽  
Author(s):  
Odette L Shotwell ◽  
William R Burg ◽  
Thomas Diller
Keyword(s):  
Thin Layer ◽  
Formic Acid ◽  
Ethyl Acetate ◽  
Aflatoxin B1 ◽  
American Association ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Acetone Water ◽  
Layer Chromatography

Abstract Methods adopted by the AOAC and the American Association of Cereal Chemists for determining aflatoxin in corn were modified, and techniques were developed for application to samples of <1 to 10 g instead of the specified 50 g samples. Analysis included chloroform extraction of dust samples or dust collected from glass fiber filters, purification of extracts on a silica gel column of appropriate size, and measurement of aflatoxin by either 1- or 2-dimensional thin layer chromatography (TLC). The solvent for 1-dimensional TLC was chloroform-acetonewater (91 + 9 + 1). Solvents for 2-dimensional TLC were, first direction, ether-methanol-water (95 + 4 + 1, lined tank) and second direction, chloroformacetone- water (91 + 9 + 1, unlined tank), or first direction, chloroform-acetone-water (91 + 9 + 1, unlined tank) and second direction, toluene-ethyl acetate- formic acid (60 + 30 + 10, unlined tank). When samples weighed ≤0.1 g, the entire concentrated extract was applied to the TLC plate. About 0.5-1.0 ng aflatoxin B1 could be detected on the plate, making the limit of detection about 9 ng/g for 0.1 g samples.

Determination of Bergapten in Fragrance Preparations by Thin Layer Chromatography and Spectrophotofluorometry

1976 ◽  
Vol 59 (3) ◽  
pp. 547-551
Author(s):  
Harris H Wisneski
Keyword(s):  
Acetic Acid ◽  
Carbon Tetrachloride ◽  
Thin Layer ◽  
Ethyl Acetate ◽  
Thin Layer Chromatography ◽  
Digital Integrator ◽  
Average Recovery ◽  
Tert Butylamine ◽  
Layer Chromatography

Abstract A method has been developed for the determination of bergapten (5-methoxypsoralen), a known phototoxin, in perfumes, colognes, and toilet waters. The bergapten and other lactonic compounds were first isolated from the sample by a series of extractions. The extract containing the bergapten was diluted to a known volume and an aliquot was spotted on a thin layer chromatographic (TLC) plate coated with silica gel G. After 2-dimensional development with hexane - carbon tetrachloride - tert - butylamine (180 + 12 + 9) and hexane-toluene-ethyl acetate-acetic acid (100+10+15+0.5), the TLC plate was dried and the emitted fluorescence of bergapten was measured, using a spectrophotofluorometer equipped with a TLC accessory and coupled to an automatic digital integrator. The amount of bergapten was determined by comparing its peak area to those of bergapten standards. The average recovery for levels of 0.001, 0.005, and 0.01% bergapten was 88%.

Thin Layer Densitometric Determination of Gallic Acid and Gallotannins in Wine and Cider

1980 ◽  
Vol 63 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Miroslav Dadic ◽  
Joris E A Van Gheluwe ◽  
Robert L Weaver
Keyword(s):  
Thin Layer ◽  
Formic Acid ◽  
Ethyl Acetate ◽  
Prussian Blue ◽  
Gallic Acid ◽  
Thin Layer Chromatography ◽  
Calibration Curve ◽  
Ethyl Formate ◽  
Layer Chromatography

Abstract Free gallic acid and total gallotannins are determined in wine and cider by thin layer densitometry. The beverage is extracted with ethyl acetate and the extract is subjected to thin layer chromatography on silica gel. After elution with chloroform-ethyl formate-formic acid (50+40+ 10), the dry plate is sprayed uniformly with a freshly prepared solution of 0.3% aqueous FeCl3 and 0.3% aqueous K3FeCN6. If the gallic acid spot appears (Rf 0.28), densitometry readings are taken at 600 nm, and free gallic acid (GAF) is calculated from the formula GAF = GA (μg, from calibration curve) × 1.25. The calibration curve was obtained by plotting thin layer densitometric readings at 600 nm (prussian blue) vs. μg gallic acid. In a second method, the beverage is hydrolyzed, and extraction and densitometry are performed as before to give “total gallic acid after hydrolysis:” GAH (mg/L) = GA (μg, from calibration curve) × 25. Total gallotannins (GALLT) are calculated from the formula: GALLT (mg/L) = GAH – GAF. Results for 10 wines and 5 ciders are presented and briefly discussed.

Confirmatory Tests for Aflatoxin B1

1964 ◽  
Vol 47 (5) ◽  
pp. 801-803 ◽  
Author(s):  
Peter John Andrellos ◽  
George R Reid
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Formic Acid ◽  
Thionyl Chloride ◽  
Aflatoxin B1 ◽  
Trifluoroacetic Acid ◽  
Reaction Products ◽  
Confirmatory Tests ◽  
Aflatoxin B ◽  
Layer Chromatography

Abstract Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.

Erythrocyte porphyrin analysis in the detection of lead poisoning in children: evaluation of four micromethods.

1976 ◽  
Vol 22 (2) ◽  
pp. 161-168 ◽  
Author(s):  
T L Hanna ◽  
D N Dietzler ◽  
C H Smith ◽  
S Gupta ◽  
H S Zarkowsky
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Lead Poisoning ◽  
Complete Recovery ◽  
Comparison Method ◽  
Working Standard ◽  
Single Extraction ◽  
Double Extraction ◽  
Poisoning In Children

Abstract We evaluated four procedures for determination of erythrocyte porphyrin: double extraction with ethyl acetate/acetic acid-HCl, single extraction with ethanol, single extraction with acetone, and direct solubilization with detergent-buffer. The ethyl acetate procedure, when used with two portions of HCl, apparently gives complete recovery of porphyrin and is suitable for reference as a comparison method. The ethanol procedure gives a high and consistent recovery and is technically simpler. The acetone procedure gives low and variable recovery of porphyrin, and the detergent-buffer method is subject to serious hemoglobin interference; neither of these two procedures offers any technical advantage. Stability of samples and methods for standardization were explored. A procedure for expressing results in terms of erythrocyte Zn-protoporphyrin content is given. Because of its stability, coproporphyrin is useful as a daily working standard. The ethyl acetate and ethanol methods are about equally efficient for detecting lead intoxication. Because of its simplicity, the ethanol method seems to be the best for use in screening.

Notizen: Improved 2,4-Dinitrophenylhydrazine, Thin Layer Chromatography Methods for the Determination of Micro- and Macroamounts of Ascorbic Acid

1974 ◽  
Vol 29 (11-12) ◽  
pp. 777-780 ◽  
Author(s):  
A. Navon ◽  
H. Z. Levinson
Keyword(s):  
Acetic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Condensation Reaction ◽  
Dehydroascorbic Acid ◽  
Previous Method ◽  
Aqueous Acetic Acid ◽  
Tlc Plates ◽  
Layer Chromatography

Microamounts of vitamin C could be readily determined in 20 μl-samples using the 2,4-dinitrophenylhydrazine method together with separation by thin layer chromato­graphy. The condensation reaction was carried out for 5 min at 100 °C on a glass fibre disc. Purification of vitamin C hydrazones was accomplished by repeated separation on TLC plates. An aqueous solution of 65% acetic acid was em­ployed to dissolve the vitamin C hydrazones, providing maxi­mal absorbance at 500 nm. The minimum amount detectable by this method is 0.4 μg of dehydroascorbic acid. The macrodetermination of vitamin C was improved by simpli­fying a previous method and employing 65% aqueous acetic acid as a solvent for the hydrazones.

Zum stoffwechsel von aromaten, II. über die muconsäurespaltung von einfachen o-diphenolen / on the metabolism of aromatic compounds, ii * the muconic acid scission of simple o-diphenols

1973 ◽  
Vol 28 (11-12) ◽  
pp. 662-674 ◽  
Author(s):  
Günther Schulz ◽  
Erich Hecker
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Ethyl Acetate ◽  
Peracetic Acid ◽  
Aromatic Compounds ◽  
Time Course ◽  
Protocatechuic Acid ◽  
Uv Light ◽  
Steric Effects ◽  
Muconic Acid

Abstract The preparation of substituted cis,cis-muconic acids by oxidative ring scission of simple o-di-phenols with peracetic acid is investigated. Scission of pyrocatechol (1) to cis,cis-muconic acid (2) gives optimal yields, if acetic acid or ethyl acetate is used as solvent and if the solution is 15-20% with respect to sulfuric acid free peracetic acid comprising a one molar excess of oxidant. Under similar conditions, 3-tosylamino-pyrocatechol yields with peracetic acid the hitherto unknown α-tosylamino-cis,cis-muconic caid (18). 18 may be converted to α-tosylamino-traras,trans-muconic acid (19) by means of iodine, UV light or heating. From protocatechuic acid (4) under similar conditions not β-carboxy-cis,cis-muconic acid (5) is obtained, but rather β-carboxy-mucono-lactone (6 b, γ-carboxymethyl-β-carboxy-Δα-butenolide). As yet, this lactone has been accessible only from an isomer of β-carboxy-cis,cis-muconic acid, the latter being obtainable by enzymatic scission of protocatechuic acid (4). Steric effects are responsible for both, the formation of the free cis,cis-muconic acids 2 and 18 from pyrocatechol (1) and α-tosylamino-pyrocatechol, and the formation of the γ-lactone 6 b instead of β -carboxy-cis,cis-muconic acid by scission of protocatechuic acid (4). The time course of the reactions shows that - compared to pyrocatechol (1) - a 3-tosylamino-group enhances the peracetic acid scission, whereas a 4-carboxygroup as in 4 slows it down

High-Pressure Liquid Chromatographic Method for the Determination of Patulin in Apple Butter

1975 ◽  
Vol 58 (4) ◽  
pp. 754-756 ◽  
Author(s):  
George M Ware
Keyword(s):  
High Pressure ◽  
Acetic Acid ◽  
Liquid Chromatography ◽  
Ethyl Acetate ◽  
Chromatographic Method ◽  
High Pressure Liquid Chromatographic ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract Patulin is extracted from apple butter samples with ethyl acetate and the extract is cleaned up on a silica gel column, using benzene-ethyl acetate (75+25) as the eluant. High-pressure liquid chromatography, using a 25 cm Zorbax-Sil column, isooctane-ethyl ether-acetic acid (750+250+0.5) as the mobile solvent, and a 254 nm ultraviolet detector, is used for the determinative step. Under these conditions, patulin is eluted before 5-hydroxymethylfurfural, a component of apple butter which interferes with other liquid chromatographic and thin layer chromatographic methods. Recoveries of patulin added at levels of 34.6, 138.4, and 276.8 μg/kg ranged from 89.0 to 112.1%.

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