A Quantitative, Semiroutine Method for Determining Algal and Sedimentary Chlorophyll Derivatives

1973 ◽  
Vol 30 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Ralph J. Daley ◽  
C. B. J. Gray ◽  
S. R. Brown
Keyword(s):  
Thin Layer ◽  
Degradation Products ◽  
Complete Analysis ◽  
Membrane Filters ◽  
Freshwater Phytoplankton ◽  
Extraction Chamber ◽  
Layer Chromatography ◽  
Chlorophyll Derivatives

An integrated, quantitative method is described for the determination of chlorophylls and chlorophyll degradation products in freshwater phytoplankton and sediments. Prior to extraction, algal samples were concentrated by filtration through glass fiber filters while sediment samples were lyophilized. All materials were extracted in a mixture of acetone, methanol, and water (80:15:5) by ultrasonication in a glass extraction chamber refrigerated at −10 C. Extracts were filtered through solvent-resistent membrane filters, rather than centrifuged, and then fractionated without prior drying by reverse-phase thin-layer chromatography on oil-impregnated layers of kieselguhr G. Using three chromatographic systems consisting of different developing solvents and oil phases (triolein, parrafin oil, and castor oil), rapid, artefact-free separations of chlorophylls a, b, and c and 18 of their derivatives were obtained. Individual pigments were estimated by direct, in situ thin-layer scanning with a filter fluorometer. The sensitivity and reproducibility of the procedure are ca. 2 ng and 11%, respectively. In routine operation, the method is fast and relatively simple, a complete analysis being accomplished in 1.5 hr.

Recent Applications of High Performance Thin Layer Chromatography and Derivative Spectrophotometry in Pharmaceutical Analysis

2020 ◽  
Vol 16 (6) ◽  
pp. 671-689
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Katarzyna Mądra-Gackowska ◽  
Piotr Kośliński ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Pharmaceutical Analysis ◽  
High Performance ◽  
Degradation Products ◽  
Derivative Spectrophotometry ◽  
Accuracy And Precision ◽  
Post Marketing ◽  
Layer Chromatography

At present, no one can imagine drug development, marketing and post-marketing without rigorous quality control at each stage. Only modern, selective, accurate and precise analytical methods for determination of active compounds, their degradation products and stability studies are able to assure the appropriate amount and purity of drugs administered every day to millions of patients all over the world. For routine control of drugs simple, economic, rapid and reliable methods are desirable. The major focus of current scrutiny is placed on high-performance thin layer chromatography and derivative spectrophotometry methods, which fulfill routine drug estimation’s expectations [1-4]. The present paper reveals state-of-the-art and possible applications of those methods in pharmaceutical analysis between 2010 and 2018. The review shows advantages of high-performance thin layer chromatography and derivative spectrophotometry, including accuracy and precision comparable to more expensive and time-consuming methods as well as additional fields of possible applications, which contribute to resolving many analytical problems in everyday laboratory practice.

Simultaneous Determination of Captan and Captafol in Apples and Potatoes by Thin Layer Chromatography and in situ Fluorometry

1977 ◽  
Vol 60 (6) ◽  
pp. 1328-1330
Author(s):  
Yves Francoeur ◽  
Victorin Mallet
Keyword(s):  
Thin Layer ◽  
Methylene Chloride ◽  
Sodium Chlorate ◽  
Simple Method ◽  
Fungicide Residues ◽  
Chromatographic Plate ◽  
Layer Chromatography ◽  
Ppm Level

Abstract A simple method is described for the simultaneous quantitative determination of captan [N-(trichloromethylthio)-3a,4,7,7a-tetrahydrophthalimide] and captafol [N-(1,1,2,2-tetrachloroethylthio)-3a,4,7,7a-tetrahydrophthalimide] in apples and potatoes. The fungicide residues are extracted with acetonitrile, partitioned into a solution of methylene chloride in petroleum ether, separated from each other and the co-extractives on a thin layer chromatographic plate impregnated with aluminum chloride, sprayed with sodium chlorate, and heated. The fluorescence is then measured directly from the chromatogram. Recoveries were greater than 90% in the test crops at the 0.2 ppm level.

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 Application of Thin-Layer Chromatography in Combination with Densitometry for the Determination of Diclofenac in Enteric Coated Tablets

2019 ◽  
Vol 12 (4) ◽  
pp. 183 ◽  
Author(s):  
Wioletta Parys ◽  
Alina Pyka-Pająk ◽  
Małgorzata Dołowy
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Degradation Products ◽  
Low Cost ◽  
Diclofenac Sodium ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Products ◽  
Enteric Coated ◽  
Layer Chromatography

Diclofenac belongs to the drug class non-steroidal anti-inflammatory drugs widely used in Europe as well as all over the world. Thus, it is important to conduct research on its quality control of available pharmaceutical preparations like for example enteric coated tablets. Among various analytical techniques, thin-layer chromatography (TLC) is ideal for this task due to their short time analysis, ease of operation and low cost. Hence, the aim of this study was to develop the optimal conditions of analysis and quantitative determination of diclofenac sodium in enteric tablets by using TLC in combination with densitometry. Of all chromatographic systems tested, the best is the one which consists of silica gel 60F254 and cyclohexane: chloroform:methanol:glacial acetic acid (6:3:0.5:0.5 v/v) as the mobile phase, which allows the successful separation of examined diclofenac sodium as active component and the largest number (twelve) of its degradation products as potential impurities of its pharmaceutical products. This indicates that the newly developed method is more effective than previously reported assays by Starek and Krzek. Linearity range was found to be 4.00–18.00 μg/spot for diclofenac sodium. The results of the assay of enteric tablet formulations equals 98.8% of diclofenac sodium in relation to label claim is in a good agreement with pharmaceutical requirements.

scholarly journals Column and Thin-Layer Chromatographic Methods for the Simultaneous Determination of Acediasulfone in the Presence of Cinchocaine, and Cefuroxime in the Presence of Its Hydrolytic Degradation Products

2007 ◽  
Vol 90 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Mohammad Abdul-Azim Mohammad ◽  
Nagwan H Zawilla ◽  
Fawzy M El-Anwar ◽  
Samir M El-Moghazy Aly
Keyword(s):  
Thin Layer ◽  
Simultaneous Determination ◽  
Mobile Phase ◽  
Degradation Products ◽  
Hydrolytic Degradation ◽  
Ammonium Hydroxide ◽  
Dosage Forms ◽  
Ultraviolet Detection ◽  
Layer Chromatography

Abstract Column liquid chromatography (LC) and thin-layer chromatography (TLC)densitometry methods are described for simultaneous determination of acediasulfone (Ace) and cinchocaine (Cinco). In the LC method, the separation and quantitation of the 2 drugs was achieved on a Zorbax C8 column (5 μm, 150 × 4.6 mm id) using a mobile phase composed of methanol-phosphate buffer, pH 2.5 (66 + 34, v/v), at a flow rate of 1 mL/min and ultraviolet detection at 300 and 327 nm for Ace and Cinco, respectively. The method showed linearity over concentration ranges of 20-200 and 45685 μg/mL, respectively. In the TLCdensitometry method, a mobile phase composed of methanol-tetrahydrofuran-acetic acid (45 + 5 + 0.5, v/v/v) was used for the separation of the 2 drugs. The linearity range was 0.5-4 and 2-9 μg/spot, respectively. In addition, stability indicating TLCdensitometry method has been developed for determination of cefuroxime sodium in the presence of 570% of its known hydrolytic degradation products. The mobile phase butanol-methanol-tetrahydrofuran-concentrated ammonium hydroxide (50 + 50 + 50 + 5, v/v/v/v) was used. The concentration range was 210 g/spot. The optimized methods proved to be specific and accurate for the analysis of the cited drugs in laboratory-prepared mixtures and dosage forms. The obtained results agreed statistically with those obtained by the reference methods.

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.

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