Computerized System to Quantify Aflatoxin Using Thin Layer Chromatography1

1990 ◽  
Vol 17 (2) ◽  
pp. 96-100 ◽  
Author(s):  
T. B. Whitaker ◽  
J. W. Dickens ◽  
A. B. Slate
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Measurement Errors ◽  
Regression Equation ◽  
Fluorescent Intensity ◽  
Percent Error ◽  
Sample Extract ◽  
Tlc Plates ◽  
Layer Chromatography ◽  
Computerized System

Abstract A microcomputer was interfaced to an instrument (spotmeter) previously designed to measure the fluorescent intensity of aflatoxin spots on thin layer chromatography (TLC) plates. Software was developed that uses a cubic regression equation to describe the relationships between the spotmeter readings and the known quantities of aflatoxin in standard spots on TLC plates. The regression technique also provides methods to detect spotting and/or measurement errors. Based on the regression equation and measurements of sample extract spots on the same TLC plate, the system computes and records the amount of aflatoxin in the sample extract spots and the concentration of aflatoxin that was in the extracted sample. The percent error associated with computed amounts of aflatoxin in sample extract spots is affected by the amount of aflatoxin in the sample extract spots and standard spots on the plate. The average percent error ranged from 14.9% for a 2.6 ng spot of 4.1% for a 13 ng spot.

Analysis of Dairy Products for Chlorinated Insecticide Residues by Thin Layer Chromatography

1966 ◽  
Vol 49 (4) ◽  
pp. 795-800
Author(s):  
William A Moats
Keyword(s):  
Aluminum Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Color Development ◽  
Tlc Plates ◽  
One Step ◽  
Rf Values ◽  
Tlc Analysis ◽  
Layer Chromatography

Abstract Butterfat and milk samples were analyzed for chlorinated insecticides by thin layer chromatography (TLC) on aluminum oxide or silica gel plates containing a small amount of silver nitrate. The adsorbent was washed with distilled water before preparing the plates. A one-step cleanup on a partially inactivated Florisil column was performed prior to TLC analysis. For color development, the TLC plates were sprayed lightly with hydrogen peroxide to suppress possible interference from fat and then steamed before exposure to ultraviolet light to accelerate and intensify the color reaction. Rf values for a number of solvent systems on aluminum oxide and silica gel plates are given. With this procedure, 0.05 μg or less of insecticide can be detected in a 0.4 g butterfat sample or the extract from 10 ml milk.

Simplified Method for Microscale Production and Quantification of Aflatoxin in Broth1

1984 ◽  
Vol 47 (7) ◽  
pp. 526-529 ◽  
Author(s):  
WEI-YUN J. TSAI ◽  
JIMMY D. LAMBERT ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Solvent Extraction ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Frozen Storage ◽  
Aflatoxin Production ◽  
Production Studies ◽  
Simplified Method ◽  
Tlc Plates ◽  
Layer Chromatography ◽  
Yeast Extract Sucrose

A simplified method for aflatoxin production studies is described. The mold was cultured in 4-dram (15 ml) vials containing 5 ml of yeast extract sucrose broth, and aflatoxin levels were determined by direct spotting of the broth on thin layer chromatography (TLC) plates and quantitating by spectrodensitometry. Equivalent levels of aflatoxins were produced in vials as compared to flasks. When compared to conventional TLC after solvent extraction, direct spotting was rapid, economical and statistically equivalent. Heating broth cultures (121°C, 15 s) before TLC improved the release of aflatoxin from mycelial mats. Aflatoxins were unstable in YES broth during 3 months of frozen storage.

scholarly journals Determination of New Antidepressants in Pharmaceuticals by Thin-Layer Chromatography with Densitometry

2010 ◽  
Vol 93 (3) ◽  
pp. 778-782 ◽  
Author(s):  
Tatána Gondová ◽  
Iveta Petríková
Keyword(s):  
Thin Layer ◽  
Stationary Phase ◽  
Thin Layer Chromatography ◽  
Mobile Phase ◽  
Pharmaceutical Formulations ◽  
Simultaneous Separation ◽  
Tlc Plates ◽  
Precision And Accuracy ◽  
Layer Chromatography

Abstract A new and simple TLC-densitometry method has been developed for the simultaneous separation of the two noradrenergic and specific serotonergic antidepressants mirtazapine and mianserine and validated for their determination in commercially available tablets. The method used TLC plates precoated with silica gel 60F254 as the stationary phase, and the mobile phase consisted of hexaneisopropanol25 ammonia (70 + 25 + 5, v/v/v). Densitometric analysis was carried out in the absorbance mode at 280 nm. The method was validated in accordance with International Conference on Harmonization guidelines in terms of linearity, LOD, LOQ, precision, and accuracy. Calibration curves were linear (R2 > 0.9970) with respect to peak area in the concentration range of 5002500 and 5005000 ng/spot for mirtazapine and mianserine, respectively. The LODs were 20 and 35 ng/spot for mirtazapine and mianserine, respectively. The described method was successfully applied to the determination of mirtazapine and mianserine in their pharmaceutical formulations with recovery ranging from 99.83 to 101.20 of the labeled amount of the compounds. The proposed method can be used in routine QC of these drugs in pharmaceutical formulations.

scholarly journals Some Observations on Thin Layer Chromatography Technique

2019 ◽  
Vol 8 (2) ◽  
pp. 1700-1702
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Potassium Permanganate ◽  
Mobile Phase ◽  
Technical Aspects ◽  
Potassium Permanganate Solution ◽  
Tlc Plates ◽  
Solvent Use ◽  
Layer Chromatography

The present study is to report the various problems faced during TLC methodology. Although used regularly some technical aspects must be kept in mind to get better and uniform results. During our experiments with TLC methods we came across some problems and here these aspects of TLC methodology are being highlighted. It is suggested that the solvent use as mobile phase should also be used for extraction of any particular phytochemical. TLC plates should be 3 to 4 mm thick, to be dried for at least 72 hrs. It is also suggested that potassium permanganate solution gives better clarity in visualizing the spots

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.

Thin-layer chromatography of free porphyrins for diagnosis of porphyria.

1989 ◽  
Vol 35 (6) ◽  
pp. 1043-1044 ◽  
Author(s):  
M J Henderson
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Screening Tests ◽  
Fluorescent Light ◽  
Comprehensive Investigation ◽  
Long Wave ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract In this simple thin-layer chromatographic (TLC) technique for evaluating porphyrin excretion, porphyrins are extracted from urine or feces, then separated on silica-gel TLC plates. The distinct porphyrin bands are observed by viewing the plates under long-wave fluorescent light. Positive screening tests can readily be confirmed or rejected, and a more comprehensive investigation confidently undertaken.

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.

scholarly journals A Rapid, Sensitive Thin Layer Chromatography Procedure for the Detection of Fumonisin B1 and B2

1992 ◽  
Vol 4 (3) ◽  
pp. 326-329 ◽  
Author(s):  
George E. Rottinghaus ◽  
Charles E. Coatney ◽  
Harry C. Minor
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fumonisin B1 ◽  
Sodium Borate ◽  
Reverse Phase ◽  
University Of Missouri ◽  
Tlc Plates ◽  
Green Fluorescent ◽  
Sodium Borate Buffer ◽  
Layer Chromatography

A thin layer chromatography (TLC) method was developed for the detection of fumonisin B1 and B2 in corn and corn-based feedstuffs. Finely ground samples were extracted with acetonitrile: water (1: 1), filtered, and applied to C18 cleanup columns. The columns were washed with 1% aqueous KCl followed by acetonitrile: 1% aqueous KC1 (1:9), and the fumonisins were eluted with acetonitrile: water (7:3). The eluants were concentrated and spotted on reverse-phase C18 TLC plates along with fumonisin B1 and B2 standards, and the plates were developed in methanol: 4% aqueous KCl (3:2). The fumonisins were visualized by spraying the TLC plates successively with 0.1 M sodium borate buffer, fluorescamine, and 0.01 M boric acid. The plates were then dried and examined under longwave ultraviolet light. Fumonisin B1 and B2 appeared as bright yellowish-green fluorescent bands at Rfs of 0.5 and 0.1, respectively. The detection limit for the fumonisins on the TLC plate was 0.1 ppm in corn. Recoveries from spiked samples averaged >80%. The identification of the fumonisins was confirmed by hydrolyzing the parent compounds of B1 and B2 to their respective C22 amino-alcohols and reexamining by TLC with the same visualizing reagents. This procedure was used to survey 193 corn samples collected from University of Missouri test plots in 1990 for fumonisin B,. Fumonisin B1 was detected in 15% of the corn samples.

scholarly journals identification of phylloquinone in cattle samples using T.L.C. method

2010 ◽  
pp. 75-78
Author(s):  
Lucian Bara
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mass Spectroscopy ◽  
Vitamin K ◽  
Direct Method ◽  
Unknown Origin ◽  
Reverse Phase ◽  
Tlc Plates ◽  
Layer Chromatography

A case of hemorrhage of unknown origin was observed in cattle and liver samples were submitted for assay of Vitamin K orpossible cuomarol. After evaluating normal and reverse phase Thin Layer Chromatography (TLC) plates and different solvents,reverse phase TLC plate with indicator and methylene chloride:methanol 70:30 were chosen for direct method of detection andindication of Vitamin K.Gass Chromatography and Densitometry were used to quantitate the Vitamin K present in liver samples andconfirmation of Vitamin K was done by Mass Spectroscopy.

scholarly journals A Toolkit to Quantify Target Compounds in Thin Layer Chromatography Experiments

2018 ◽  
Author(s):  
Stuart Ibsen ◽  
Niamh Mac Fhionnlaoich ◽  
Luis Serrano ◽  
Alaric Taylor ◽  
Runzhang Qi ◽  
...  
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Rhodamine 6G ◽  
Lesson Plan ◽  
Quantitative Information ◽  
Educational Setting ◽  
Unknown Sample ◽  
Tlc Plates ◽  
Sudan Iv ◽  
Layer Chromatography

Thin layer chromatography (TLC) is one of the basic experimental procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative analysis in a lesson plan. We provide a free, stand-alone software that allows students to obtain quantitative information and present two suitable experiments, namely the absorbance-based quantification of the colorant Sudan IV and the fluorescence-based quantification of Rhodamine 6G, a fluorophore widely used in biotechnology. Students conduct TLC experiments following established routes, then take pictures of their TLC plates with their mobile phones and finally quantify the amount of different compounds in the separate bands they observe.

Sign in / Sign up

Export Citation Format

Share Document