Thin Layer Chromatography of Dinitrophenol Pesticides

1966 ◽  
Vol 49 (6) ◽  
pp. 1166-1169
Author(s):  
George Yip ◽  
Samuel F Howard
Keyword(s):  
Thin Layer ◽  
Lower Limit ◽  
Complete Resolution ◽  
Stannous Chloride ◽  
Limit Of Detection ◽  
Uv Light ◽  
Mineral Oil ◽  
Immobile Phase ◽  
Yellow Orange ◽  
Layer Chromatography

Abstract Four dinitrophenol pesticides, DNOC, DNBP, DNAP, and DNOCHP, can be separated on cellulose thin layer plates, either as the phenols or their methyl ethers. Methyl ethers are prepared by reaction with diazomethane. Partition chromatography between an immobile phase of mineral oil and a mobile aqueous phase gives complete resolution. The compounds are revealed by spraying first with stannous chloride, then with p-dimethylaminobenzaldehyde to yield yellow-orange spots which fluoresce under UV light. The lower limit of detection in the phenolic form varies with the compound, ranging from 0.05 μg for DNOC to 0.3 μg for DNOCHP. The lower limit for the ethers is the same for all compounds, 0.1 pg.

Colorimetric Determination of Terreic Acid Produced by Aspergillus terreus

1978 ◽  
Vol 61 (3) ◽  
pp. 581-583
Author(s):  
Thirugnana Subramanian ◽  
Kuppuswamy Mohan Namasivayam ◽  
Edayathimangalam R B Shanmugasundaram
Keyword(s):  
Thin Layer ◽  
Ethyl Acetate ◽  
Thin Layer Chromatography ◽  
Lower Limit ◽  
Minimal Medium ◽  
Aspergillus Terreus ◽  
Limit Of Detection ◽  
Colorimetric Determination ◽  
Layer Chromatography

Abstract Two methods have been developed for determining terreic acid, which is a mycotoxin produced by Aspergillus terreus, a common food contaminant. The organism was grown independently in synthetic minimal medium, bread, and rice. After 15 days of growth, the toxin was extracted with ethyl acetate, cleaned up by thin layer chromatography, and determined colorimetrically, using Folin's reagent or 2,4- dinitrophenylhydrazine. The production of terreic acid was greater on bread than on rice or minimal medium. Recoveries of 200–400 ≧g terreic acid/100 g bread and rice ranged from 62 to 98%. The lower limit of detection was 200 ≧g/100 g.

scholarly journals DETERMINATION OF 10-GINGEROL IN INDIAN GINGER BY VALIDATED HPTLC METHOD OF SAMPLES COLLECTED ACROSS SUBCONTINENT OF INDIA

2016 ◽  
Vol 8 (12) ◽  
pp. 190
Author(s):  
Kamran Ashraf ◽  
Syed Adnan Ali Shah ◽  
Mohd Mujeeb
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Aluminum Plates ◽  
Layer Chromatography ◽  
Hptlc Method

<p><strong>Objective: </strong>A simple, sensitive, precise, and accurate stability indicating HPTLC (high-performance thin-layer chromatography) method for analysis of 10-gingerol in ginger has been developed and validated as perICH guidelines.</p><p><strong>Methods: </strong>The separation was achieved on TLC (thin layer chromatography) aluminum plates pre-coated with silica gel 60F<sub>254</sub> using n-hexane: ethyl acetate 55:45 (%, v/v) as a mobile phase. Densitometric analysis was performed at 569 nm.</p><p><strong>Results: </strong>This system was found to have a compact spot of 10-gingerol at <em>R</em><sub>F</sub> value of 0.57±0.03. For the proposed procedure, linearity (<em>r</em><sup>2</sup> = 0.998±0.02), limit of detection (18ng/spot), limit of quantification (42 ng/spot), recovery (ranging from 98.35%–100.68%), were found to be satisfactory.</p><p><strong>Conclusion: </strong>Statistical analysis reveals that the content of 10-gingerol in different geographical region varied significantly. The highest and lowest concentration of 10-gingerol in ginger was found to be present in a sample of Patna, Lucknow and Surat respectively which inferred that the variety of ginger found in Patna, Lucknow are much superior to other regions of India.</p>

Rapid Thin Layer Chromatographic Determination of Aflatoxin M1 in Powdered Milk

1985 ◽  
Vol 68 (5) ◽  
pp. 952-954
Author(s):  
Maria Luisa Serralheiro ◽  
Maria Lurdes Quinta
Keyword(s):  
Aqueous Solution ◽  
Carbon Tetrachloride ◽  
Thin Layer ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Aflatoxin M1 ◽  
Powdered Milk ◽  
Layer Chromatography

Abstract A method has been developed for the detection of aflatoxin Mi in milk. The toxin is extracted with chloroform, the extract is evaporated, and the residue is partitioned between carbon tetrachloride and an aqueous saline-methanol solution. The toxin is once again extracted with chloroform from the methanol solution and analyzed by thin layer chromatography. The limit of detection of Mi in powdered milk is 0.5 μg/ kg; recoveries of added Mj are about 83%. The limit of detection can be improved to 0.3 μg/kg if the plate is sprayed with an aqueous solution of H2S04 after development.

scholarly journals Rapid Identification and Quantitation of Clotrimazole, Miconazole, and Ketokonazole in Pharmaceutical Creams and Ointments by Thin-Layer Chromatography–Densitometry

1996 ◽  
Vol 79 (3) ◽  
pp. 656-660 ◽  
Author(s):  
Utpal Roychowdhury ◽  
Saroj K Das
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Uv Light ◽  
Internal Standard ◽  
Solvent System ◽  
Short Wave ◽  
Rapid Identification ◽  
Pharmaceutical Creams ◽  
Liquid Chromatographic ◽  
Layer Chromatography

Abstract Thin-layer chromatography (TLC)–densitometry was used to separate, identify, and quantitate clotrimazole, miconazole, and ketokonazole (alone or combined with other drugs) in various pharmacopoeial or proprietary creams and ointments. Clotrimazole was extracted from the cream or ointment with ethyl alcohol, and miconazole and ketokonazole were extracted with a mixture of equal volumes of chloroform and isopropyl alcohol. Active ingredients were separated from excipients and other drugs by TLC on a precoated silica gel F254 plate with a solvent system of n-hexane–chloroform–methanol–diethylamine (50 + 40 + 10 + 1, v/v). The 3 azoles were well separated and easily identified in this chromatographic system. The separated azoles were visualized under short-wave UV light and quantitated by scanning densitometry at 220 nm by comparing the integrated areas of samples with those of standard (one azole was used as internal standard for the other). Recoveries from samples spiked with known amounts of azoles were excellent. The method was validated further by comparison with official liquid chromatographic methods.

Selection of a Simple and Sensitive Method for Detecting Zearalenone in Corn

1994 ◽  
Vol 77 (4) ◽  
pp. 939-941 ◽  
Author(s):  
Nora M Quiroga ◽  
Inés Sola ◽  
Edith Varsavsky
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Lead Acetate ◽  
Limit Of Detection ◽  
Acetate Solution ◽  
Average Recovery ◽  
Lead Acetate Solution ◽  
Layer Chromatography ◽  
Selection Of ◽  
Sensitive Method

Abstract A simple, rapid, and sensitive method for determining zearalenone in corn was selected. The toxin was extracted from 50 g test portions with 180 mL acetonitrile and 20 mL 4% KCl solution. A portion of the extract was defatted with isooctane. The acetonitrile extract was cleaned up with 20% lead acetate solution. The zearalenone was partitioned into toluene. The toluene solution was dried, and the residue was redissolved in benzene. The toxin was determined by thin-layer chromatography with silica gel plates and chloroform–acetone (9 +1) as the developing solvent. The overall average recovery of zearalenone from corn was 97%. The limit of detection was 50 μg/kg; this limit may be lowered by using fast violet B salt as spray reagent. The method was compared with 2 previous methods that determine zearalenone in biologically contaminated corn.

scholarly journals Quantitative Determination of Triterpenes from Amphiptherygium adstringens by Liquid Chromatography and Thin-Layer Chromatography and Morphological Analysis of Cuachalalate Preparations

2006 ◽  
Vol 89 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Andrés Navarrete ◽  
Bharathi Avula ◽  
Vaishali C Joshi ◽  
Xiuhong Ji ◽  
Paul Hersh ◽  
...  
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Gastric Ulcers ◽  
Array Detector ◽  
Plant Materials ◽  
Relative Standard ◽  
Layer Chromatography

Abstract Amphiptherygium adstringens (Anacardiaceae/Julianaceae), local name cuachalalate, is used in folk medicine for the treatment of cholelithiasis, fevers, fresh wounds, hypercholesterolemia, gastritis, gastric ulcers, and cancer of the gastrointestinal tract. The development of column high-performance liquid chromatographyphotodiode array detector (LC-PDA) and high-performance thin-layer chromatography (HPTLC)densitometry methods for the determination of masticadienonic acid and 3-hydroxymasticadienonic acid in cuachalalate preparations is described in this paper. Good separation of the compounds could be achieved by both methods. Either might be preparable depending on the requirements. The LC separation was performed on a Phenomenex Synergi MAX-RP 80A reversed-phase column operated at 40C with detection at 215 nm. The plant materials were extracted with methanol by sonication. The triterpenes present in the plant material and commercial extracts were separated with an acetonitrilewater reagent alcohol isocratic system. The limit of detection was 0.10.2 g/mL. The relative standard deviation values for the determination of triterpenes in plant extracts were less than 1.00%. This is the first report of an analytical method developed for the quantitative analysis of triterpenes from Amphiptherygium adstringens by LC-PDA and HPTLC. The stem bark showed higher amounts of triterpenes, and low amounts in root and stem root. The microscopic description of the crude drug of cuachalalate was also provided.

Determination of Biphenyl in Citrus Fruits by Thin Layer Chromatography and Ultraviolet Spectrophotometry

1967 ◽  
Vol 50 (4) ◽  
pp. 934-938
Author(s):  
Paul E Corneliussen
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Uv Light ◽  
Preparative Thin Layer Chromatography ◽  
Mean Deviation ◽  
Citrus Fruits ◽  
Ultraviolet Spectrophotometry ◽  
Spectrophotometric Measurement ◽  
Layer Chromatography

Abstract A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.

scholarly journals Visualization of Aspalathin in Rooibos (Aspalathus linearis) Plant and Herbal Tea Extracts Using Thin-Layer Chromatography

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 938 ◽  
Author(s):  
Emily Amor Stander ◽  
Wesley Williams ◽  
Fanie Rautenbach ◽  
Marilize Le Roes-Hill ◽  
Yamkela Mgwatyu ◽  
...  
Keyword(s):  
Quality Control ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Throughput Screening ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Herbal Tea ◽  
Limit Of Quantification ◽  
Aspalathus Linearis ◽  
Layer Chromatography

Aspalathin, the main polyphenol of rooibos (Aspalathus linearis), is associated with diverse health promoting properties of the tea. During fermentation, aspalathin is oxidized and concentrations are significantly reduced. Standardized methods for quality control of rooibos products do not investigate aspalathin, since current techniques of aspalathin detection require expensive equipment and expertise. Here, we describe a simple and fast thin-layer chromatography (TLC) method that can reproducibly visualize aspalathin in rooibos herbal tea and plant extracts at a limit of detection (LOD) equal to 178.7 ng and a limit of quantification (LOQ) equal to 541.6 ng. Aspalathin is a rare compound, so far only found in A. linearis and its (rare) sister species A. pendula. Therefore, aspalathin could serve as a marker compound for authentication and quality control of rooibos products, and the described TLC method represents a cost-effective approach for high-throughput screening of plant and herbal tea extracts.

Quantitation of Sulfamethazine in Pork Tissue by Thin-Layer Chromatography

1993 ◽  
Vol 76 (2) ◽  
pp. 335-341 ◽  
Author(s):  
Joseph Unruh ◽  
Daniel P Schwartz ◽  
Robert A Barford
Keyword(s):  
Thin Layer ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Internal Standard ◽  
Signal To Noise ◽  
Thin Layer Chromatographic Plate ◽  
Average Accuracy ◽  
Chromatographic Plate ◽  
Layer Chromatography

Abstract Our earlier method to detect and quantitate sulfamethazine (SMZ) in milk at the 10 ppb level was modified to quantitate SMZ in pork tissue. Sulfabromomethazine (SBZ) is added to the tissue as an internal standard. SMZ and SBZ are extracted from the tissue into water as the supernatant of a centrifuged, aqueous homogenate and are cleaned up and concentrated by a series of solid-phase extractions. The sulfonamide-containing eluate is then separated on a silica gel thin-layer chromatographic plate. SBZ and SMZ are derivatized with fluorescamine, and their fluorescence is quantitated with a scanning densitometer. The limit of detection was estimated at 0.25 ppb (signal-to-noise ratio, 3:1). The average accuracy over the analysis range (0.54-21.8 ppb [μg/kg]) was 95.6% (standard deviation = 29.4%, n = 54).

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