Improved Thin Layer Chromatographic Method for the Isolation and Estimation of Sterigmatocystin in Grains

1977 ◽  
Vol 60 (1) ◽  
pp. 104-106
Author(s):  
Albert K Athnasios ◽  
Gustav O Kuhn
Keyword(s):  
Acetic Acid ◽  
High Resolution ◽  
Thin Layer ◽  
Fluorescence Intensity ◽  
Chromatographic Method ◽  
Yellow Corn ◽  
Chcl3 Extract ◽  
Tlc Plates ◽  
Column Chromatographic ◽  
Initial Extraction

Abstract A modified thin layer chromatographic (TLC) method has been developed in conjunction with the method of Stack and Rodricks which effectively separates sterigmatocystin from interfering materials and eliminates the time-consuming column chromatographic cleanup step. Initial extraction with acetonitrile-water (9+1) containing KCl is followed by partition of the extract first against hexane and then against CHCl3. The CHCl3 extract is evaporated and the residue is dissolved in benzene and applied directly to pre-coated high resolution TLC plates, which are developed in benzene-acetic acid (90+10). Visualization of the sterigmatocystin on TLC plates is enhanced by an AlCl3 spray reagent, and concentrations of sterigmatocystin as low as 50 μg/kg can be estimated by comparing fluorescence intensity against a pure sterigmatocystin standard. The method has been applied to barley, white and yellow corn, oats, and wheat. Recoveries of added toxin in the range of 50—400 μg/kg ranged from 86.3% for yellow corn and oats to >96% for barley, wheat, and white corn.

Collaborative Study of a Column Chromatographic Method for Chlorothiazide, Methyclothiazide, and Polythiazide

1973 ◽  
Vol 56 (3) ◽  
pp. 677-680
Author(s):  
F Raymond Fazzari
Keyword(s):  
Acetic Acid ◽  
Spectrophotometric Determination ◽  
Organic Phase ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Standard Deviations ◽  
Column Chromatographic

Abstract Chlorothiazide is eluted from a K2HPO4 column with acetic acid-ether solvent and extracted from the organic phase into HCl for the Spectrophotometric determination. Methyclothiazide and polythiazide are eluted from a NaHCO3 column with CHCl3 and measured directly. The method was collaboratively studied by 10 analysts. The average per cent recovered and standard deviations for preparations of chlorothiazide and methyclothiazide were 100.2±0.67 and 99.8±1.64, respectively. The method for chlorothiazide and methyclothiazide has been adopted as official first action.

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.

Rapid Thin Layer Chromatographic Method for Determining Aflatoxin Bi, Ochratoxin A, and Zearalenone in Corn

1978 ◽  
Vol 61 (3) ◽  
pp. 584-585
Author(s):  
Ivan Balzer ◽  
Čedo Bogdanić ◽  
Stjepan Pepeljnjak
Keyword(s):  
Sodium Bicarbonate ◽  
Thin Layer ◽  
Ochratoxin A ◽  
Ultraviolet Light ◽  
Aflatoxin B1 ◽  
Chromatographic Method ◽  
Limits Of Detection ◽  
Chloroform Extraction ◽  
Tlc Plates

Abstract A multimycotoxin thin layer chromatographic method is described for the analysis of corn. Aflatoxins are extracted from the samples with acetonitrile-water, and sodium bicarbonate is added to separate the acidic ochratoxin from zearalenone and aflatoxin B1. After chloroform extraction, 1/V NaOH is added to separate zearalenone and aflatoxin B1# The separated mycotoxins are spotted on TLC plates, which are then examined under ultraviolet light. The following recoveries ( % ) were obtained for corn samples: aflatoxin B1 71, ochratoxin A 87, and zearalenone 85. The limits of detection for the respective mycotoxins were 2, 40, and 200 ppb.

Thin Layer Chromatographic Determination of Citrinin

1979 ◽  
Vol 62 (1) ◽  
pp. 201-202 ◽  
Author(s):  
Robert D Stubblefield
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Linear Relationship ◽  
Silica Gel ◽  
Coefficient Of Variation ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Tlc Plates

Abstract Clearly defined zones of citrinin can be obtained on thin layer chromatographic (TLC) plates and measured by fluorodensitometry. Silica gel plates were prepared as a slurry with aqueous 0.05M Na2EDTA (ethylenediaminetetraacetic acid), spread at 0.5 mm wet thickness, and activated at 105°C for 1 hr. Plates were developed in acetic acid-benzene (5+95). The limit of detection was 10 ng citrinin/zone. Densitometric analysis (365 nm excitation, 505 nm emission) revealed that a linear relationship exists for levels of 10 ng to at least 100 ng/zone wtih a coefficient of variation of ±5%.

Susceptibility of Strawberries, Blackberries, and Cherries to Aspergillus Mold Growth and Aflatoxin Production

1982 ◽  
Vol 65 (3) ◽  
pp. 659-664 ◽  
Author(s):  
Gerald C Llewellyn ◽  
Thomas Eadie ◽  
William V Dashek
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mycelial Growth ◽  
Methylene Chloride ◽  
Aflatoxin Production ◽  
Solvent System ◽  
Mold Growth ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract The susceptibility of blackberries, cherries, and strawberries to Aspergillus growth and aflatoxin production has been examined. Three aflatoxigenic isolates of Aspergillus, A. flavus ATCC 15548 and NRRL 3251 as well as A. parasiticus NRRL 2999, were cultured on homogenates of the fruits for 14 days at 28 ± 2°C. Percent mycelial growth and spore infestation were determined each day with a calibrated grid. At day 14 each culture was frozen at –5°C until aflatoxins were extracted with methylene chloride and water. Aflatoxins were separated by thin layer chromatography (TLC) with benzene-methanol-acetic acid (90 + 5 + 5). This extraction and solvent system provided satisfactory separations of the aflatoxins and was free of background interference on the TLC plates. Although all fruits served as substrates for both Aspergillus growth and aflatoxin production, cherries appeared to be a more favorable substrate than did blackberries, and the latter was more favorable than strawberries. Whereas A. flavus produced both B1 and G1 on all substrates, it yielded B2 and G2 only on cherries. Although A. parasiticus NRRL 2999 synthesized B1, B2, G1, and G2 on both blackberries and cherries, no aflatoxins were detected on strawberries. In contrast, A. flavus NRRL 3251 failed to produce detectable levels of aflatoxin on any substrate. All substrates supported both mycelial growth and subsequent sporulation with cherries > blackberries > strawberries.

Collaborative Study of a Column Chromatographic Method for Bendroflumethiazide and Cyclothiazide

1976 ◽  
Vol 59 (1) ◽  
pp. 90-92
Author(s):  
Frank R Fazzari
Keyword(s):  
Acetic Acid ◽  
Sodium Carbonate ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Ultraviolet Spectrophotometry ◽  
Standard Deviations ◽  
Column Chromatographic

Abstract Bendroflumethiazide and cyclothiazide are eluted from a sodium carbonate column with chloroform-acetic acid (98+2) and are measured directly by ultraviolet spectrophotometry. The method was collaboratively studied by 8 analysts. The average per cent recovery and standard deviations for simulated mixes of bendroflumethiazide and cyclothiazide were 99.61±0.94 and 98.85±3.28, respectively. For commercial preparations the respective values were 99.52±0.78 and 99.3±1.97. The method has been adopted as official first action for the determination of bendroflumethiazide.

scholarly journals A Rapid Thin Layer Chromatographic Method for Simultaneous Screening of Albendazole and Ivermectin in Formulations Prescribed for Human or Veterinary Use

2019 ◽  
Vol 31 (4) ◽  
pp. 896-900
Author(s):  
R.P. Pawar ◽  
P. Mishra ◽  
A. Durgbanshi ◽  
D. Bose
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Pharmaceutical Preparations ◽  
Cost Effective ◽  
Dosage Forms ◽  
Thin Layer Chromatographic Plate ◽  
Rf Values ◽  
Chromatographic Plate

An easy and selective thin layer chromatographic method has been developed and experimentally validated for the simultaneous screening of most commonly used anthelmintic drugs i.e. albendazole and ivermectin. Separation of these compounds was attained on silica gel 60 F254 pre-coated thin layer chromatographic plate using an optimized mobile phase of diisopropyl ether:ethyl acetate:glacial acetic acid in the ratio of 7:3:0.1 (v/v), respectively at pH 3.5. The calculated Rf values for albendazole and ivermectin were 0.65 and 0.38, respectively and the LOD was found to be 25 μg/ml and 30 μg/ml for albendazole and ivermectin, respectively. The developed method is selective, sensitive, robust, cost effective, eco-friendly, rapid as well as easy to perform. The developed method was successfully applied for the analysis of albendazole and ivermectin in pharmaceutical preparations marketed as oral suspensions, powder, tablets and injectable of the single or combined dosage forms for human as well as veterinary use. It could also be applied for the simultaneous analysis of both the compounds in other samples.

Rapid Thin Layer Chromatographic Method for the Detection of Histamine in Fish Products

1976 ◽  
Vol 59 (6) ◽  
pp. 1224-1225 ◽  
Author(s):  
David E Schutz ◽  
George W Chang ◽  
Leonard F Bjeldanes
Keyword(s):  
Thin Layer ◽  
Chromatographic Separation ◽  
Chromatographic Method ◽  
Ammonium Hydroxide ◽  
Fish Products ◽  
Fish Flesh ◽  
Fish Samples ◽  
Tlc Plates

Abstract A rapid, convenient thin layer chromatographic (TLC) method for detecting histamine in fish samples is described. Samples of press juice or fish flesh are applied directly to TLC plates. The plates are developed with acetone-ammonium hydroxide (95+5) and the spots are visualized with ninhydrin or Pauly’s reagent. Chromatographic separation of histamine from other fish components is readily achieved by this method.

Simplified Qualitative Analysis of Glycerides Derived from Coconut Oil Using Thin Layer Chromatography

2012 ◽  
Vol 506 ◽  
pp. 182-185 ◽  
Author(s):  
Sirikarn Pengon ◽  
Chutima Limmatvapirat ◽  
Sontaya Limmatvapirat
Keyword(s):  
Acetic Acid ◽  
Qualitative Analysis ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Cocos Nucifera ◽  
Coconut Oil ◽  
Solvent System ◽  
Tlc Plates ◽  
Solvent Systems ◽  
Layer Chromatography

Coconut (Cocos nucifera L.) oil is composed predominately of medium-chain triglycerides which have been reported to be beneficial to human health. It also contains free fatty acids (FFAs) which can combine with glycerol to form monoglycerides, diglycerides, and triglycerides. The analysis of FFAs and their glycerides has been proposed to assess the quality of coconut oil used as raw materials in various industrial fields. The aim of this study was to develop the qualitative method for investigation of FFA and their glycerides in coconut oil using thin layer chromatography (TLC). Coconut oil and standards of FFA and their glycerides were chromatographed separately on Silica gel 60 F254 TLC plates using hexane: ether: acetic acid (60:40:1) and hexane: ethyl acetate: acetic acid (60:40:0.5) as solvent systems A and B, respectively. The spots on developing TLC plates were detected and compared using 254-nm UV light and iodine vapor. The results showed that the resolution of solvent system A was better than that of solvent system B. However, both solvent systems were used to confirm the results. The retention factor (Rf) values of the components were in good agreement with their polarity. This method should provide a guideline for qualitative analysis of coconut oil.

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