Determination of Matacil and Zectran by Fluorigenic Labeling, Thin Layer Chromatography, and In Situ Fluorimetry

1972 ◽  
Vol 55 (6) ◽  
pp. 1259-1264
Author(s):  
R W Frei ◽  
J F Lawrence
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Sulfonyl Chloride ◽  
Relative Standard ◽  
Dansyl Derivatives ◽  
Layer Chromatography ◽  
Derivatives Of ◽  
Fluorescent Derivatives

Abstract The fluorigenic labeling of Matacil (4-dimethylamino- m-tolyl N-methylcarbamate) and Zectran (4-dimethylamino-3,5-xylyl Wmethylcarbamate) with dansyl chloride (1-dimethylamino- naphthalene-5-sulfonyl chloride) results in 3 fluorescent derivatives, and labeling with NBD-Cl (4-chloro-7-nitrobenzo- 2,1,3-oxadiazole) produces 2 fluorescent derivatives for each carbamate, all of which can be separated by thin layer chromatography (TLC). These derivatives are identified by nuclear magnetic resonance, infrared, and fluorescence spectroscopy, aided by TLC data. The carbamates are hydrolyzed in dilute base and the resulting amine or phenol hydrolysis products react with the labeling reagents. The derivatives are analyzed by TLC and in situ fluorimetry with a spectrophotometer in the fluorescence mode and a spectrophotofluorometer with the thin layer scanning accessory. Reactions, fluorescence phenomena, and chromatographic properties of the derivatives are investigated for evaluation of the method as a quantitative technique. A reproducibility of 3–5% relative standard deviation can be expected in the concentration range from 15 to 300 ng/spot for derivatives of the 2 labeling procedures. The dansyl derivatives are instrumentally detectable as low as 1 ng/spot while the NBD derivatives may be detected at concentrations of less than 0.5 mg/spot.

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.

scholarly journals Determination of mono- and diacylglycerols from E 471 food emulsifiers in aerosol whipping cream by high-performance thin-layer chromatography–fluorescence detection

2020 ◽  
Vol 412 (27) ◽  
pp. 7441-7451
Author(s):  
Claudia Oellig ◽  
Max Blankart ◽  
Jörg Hinrichs ◽  
Wolfgang Schwack ◽  
Michael Granvogl
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fluorescence Detection ◽  
High Performance ◽  
Food Additives ◽  
German Market ◽  
Relative Standard ◽  
Model Aerosol ◽  
Layer Chromatography

Abstract Mono- and diacylglycerol (MAG and DAG) emulsifiers (E 471) are widely applied to regulate techno-functional properties in different food categories, for example, in dairy products. A method for the determination of MAG and DAG in aerosol whipping cream by high-performance thin-layer chromatography with fluorescence detection (HPTLC–FLD) after derivatization with primuline was developed. For sample preparation, aerosol whipping cream was mixed with ethanol, followed by the addition of water and liquid-liquid extraction with tert-butyl methyl ether. The sample extracts were analyzed by HPTLC–FLD on silica gel LiChrospher plates with n-pentane/n-hexane/diethyl ether (22.5:22.5:55, v/v/v) as mobile phase, when interfering matrix like cholesterol and triacylglycerols were successfully separated from the E 471 food additives. For quantitation, an emulsifier with known composition was used as calibration standard and the fluorescent MAG and DAG were scanned at 366/> 400 nm. Limits of detection and quantitation of 4 and 11 mg/100 g aerosol whipping cream were obtained for both monostearin and 1,2-distearin, respectively, and allowed the reliable quantitation of MAG and DAG from E 471 far below commonly applied emulsifier amounts. Recoveries from model aerosol whipping cream with 400 mg E 471/100 g were determined in a calibration range of 200–600 mg E 471/100 g sample and ranged between 86 and 105% with relative standard deviations below 7%. In aerosol whipping creams from the German market, E 471 amounts ranged between 384 and 610 mg/100 g.

Determination of drugs in plasma by high-performance thin-layer chromatography.

1978 ◽  
Vol 24 (8) ◽  
pp. 1386-1392 ◽  
Author(s):  
D C Fenimore ◽  
C M Davis ◽  
C J Meyer
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Large Scale ◽  
Ultraviolet Spectrophotometry ◽  
Reflectance Spectrometry ◽  
Ultraviolet Reflectance ◽  
Layer Chromatography

Abstract High-performance thin-layer chromatography was used to determine chlorpromazine, amitriptyline, nortriptyline, imipramine, desipramine, phenobarbital, and phenytoin in plasma, to demonstrate the utility of this technique for routine analysis. We quantitated the separated components by use of ultraviolet reflectance spectrometry with detection limits as low as 1 microgram/liter. Regressions of psychoactive agents extracted from plasma were linear over the range of 0 to 300 microgram/liter. The anti-convulsant drugs, phenobarbital and phenytoin, were determined over a range of 0 to 50 mg/liter. Analyses were rapid, reproducible, and well-suited to large-scale programs. Separated components also can be identified in situ by ultraviolet spectrophotometry.

Determination of Quinomethionate (6-Methylquinoline-2,3-diyldithiocarbonate) Residues in Crops by In Situ Fluorometry

1976 ◽  
Vol 59 (1) ◽  
pp. 172-173
Author(s):  
Yves Francoeur ◽  
Victorin Mallet
Keyword(s):  
Thin Layer ◽  
Quantitative Determination ◽  
Petroleum Ether ◽  
Thin Layer Chromatography ◽  
Pesticide Residue ◽  
Simple Method ◽  
Layer Chromatography ◽  
Ppm Level

Abstract A simple method is described for the quantitative determination of quinomethionate (6-methylquinoline-2,3-diyldithiocarbonate) in crops. The pesticide residue is extracted with acetonitrile and partitioned in petroleum ether. After separation from the co-extractives by thin layer chromatography (TLC), the fluorescence is measured directly on a silica gel TLC plate. An average of 89% recovery is obtained at the 0.05 ppm level in apples, peaches, pears, and tomatoes.

scholarly journals Thin-Layer Chromatography-Densitometric Measurements for Determination of N-(Hydroxymethyl)nicotinamide in Tablets and Stability Evaluation in Solutions

2008 ◽  
Vol 91 (5) ◽  
pp. 1186-1190 ◽  
Author(s):  
Urszula Hubicka ◽  
Jan Krzek ◽  
Justyna uka
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Limit Of Detection ◽  
Good Precision ◽  
First Order ◽  
Kinetic And Thermodynamic Parameters ◽  
Relative Standard ◽  
Basic Solutions ◽  
Layer Chromatography

Abstract A thin-layer chromatography (TLC)-densitometric method was developed to determine N-(hydroxymethyl)nicotinamide in tablets and basic solutions along with nicotinic acid. Analysis was performed on silica gel F254 plates using chloroformethanol (2 + 3, v/v) mobile phase. The densitometric observations were made at 260 nm. The results showed good precision and accuracy; relative standard deviation was 2.37, and recovery ranged from 97.60 to 100.82. The limit of detection was 0.1 g/spot, while the linearity range was from 0.2 to 1.75 g/spot. Applicability of the newly developed method was tested for determination of N-(hydroxymethyl)nicotinamide in the preparation Cholamid<sup/>. Densitometric measurements were used to evaluate stability of N-(hydroxymethyl)nicotinamide in basic solutions. It was found that decomposition corresponded to first-order reaction kinetics. The computed kinetic and thermodynamic parameters at 30C were as follows: k 0.00675/min, t0,5 1.71 h, t0,1 0.26 h, and Ea 44.75 kJ/mol.

Extraction and Thin Layer Chromatography of Aflatoxin Bi in Mixed Feeds

1983 ◽  
Vol 66 (3) ◽  
pp. 582-586
Author(s):  
Gail M Shannon ◽  
Odette L Shotwell ◽  
William F Kwolek
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Aflatoxin B1 ◽  
Methylene Chloride ◽  
Relative Standard ◽  
Mixed Feeds ◽  
Layer Chromatography ◽  
Commercial Turkey ◽  
Different Levels

Abstract A method was developed for the determination of aflatoxin B1 in commercially prepared feeds. The method incorporates methylene chloride and citric acid solution extraction, cleanup on a small silica gel column, and thin layer chromatography for quantitation. Commercial turkey starter, catfish chow, medicated pig starter, broiler finisher, rabbit chow, horse feed, rat chow, and dog chow were investigated. The feeds were spiked with naturally contaminated corn at 4 different levels of aflatoxin B1 (16-130 μg/kg). Three assays were run on each of the 32 combinations of feed and levels of aflatoxin. Mean recoveries were 85.9-92.8% at levels of 16.5,32.9,65.8, and 131.6 μg/kg. The relative standard deviation per assay was 18.6%. This method is more rapid and less involved than most previously published methods for mixed feeds.

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