TLC-densitometric Method Research Articles

Determination of Allantoin in Drug Preparations by Quantitative High Performance TLC

Abstract A densitometric TLC method was developed for the quantification of allantoin in creams and suppositories used to treat vaginal infections. Allantoin was extracted with water at elevated temperature, diluted to a known volume, and separated by HP silica gel TLC. Allantoin was detected by spraying with p-dimethylamine-benzaldehyde reagent. The absorption of standards and samples was compared by in situ scanning. Recoveries of allantoin from authentic samples ranged from 96–102%, except for one sample that assayed high. The accuracy of the method was demonstrated by standard addition analysis of this sample.

Determination of Sulfanilamide and Sulfisoxazole in Drug Preparations by Quantitative High Performance TLC

Abstract A densitometric TLC method was developed for quantification of sulfanilamide and sulfisoxazole in creams, supppositories, and tablets. The sulfas were extracted into acidic ethanol, diluted to an appropriate volume, and separated by silica gel HPTLC. The fluorescence quenching of the sulfa zones in samples and standards was compared by in situ scanning. Recoveries of the drugs from authentic samples ranged from 96–105%. Recoveries from products with old expiration dates were low. Identity of the sulfa drugs in products was confirmed by application of fluorescamine and Bratton-Marshall detection reagents.

Determination of Aminacrine Hydro-Chloride in Drug Preparations by TLC with Fluorescence Densitometry

Abstract A densitometric TLC method was developed for quantification of aminacrine hydrochloride in creams, jellies, and suppositories. Aminacrine was extracted into acidic ethanol, diluted to a known volume, and separated by high performance silica gel TLC. The fluorescence of aminacrine zones in samples and standards was compared by in situ scanning. Recoveries of aminacrine from authentic samples ranged from 95.4 to 103.4%.

Metabolic fate of Qinghaosu in rats; a new TLC densitometric method for its determination in biological material.

Since the sixties, the emergence of malarial parasites resistant to the most potent anti-malarials has posed a serious problem to the therapy of malaria. Qinghaosu, a new sesquiterpene isolated from a Chinese medicinal herb Qing-hao (Artemisia annua Linn) is being used for the treatment of malaria in China with good results even in cases resistant to common anti-malarial agents. In this paper, a sensitive method of high specificity using TLC for the determination of Qinghaosu in biological specimens and in the study of the metabolism of the drug in rats is described. Qinghaosu was shown to be completely and rapidly absorbed after oral administration. However, a very low plasma level was obtained even after a dose of 300 mg/kg. Liver was found to be the chief site of its inactivation. When Qinghaisu was given intramuscularly, significant and more persistent plasma levels were detected. Qinghaosu was shown to pass the blood-brain and blood-placenta barriers after i.v. injection. Very little unchanged Qinghaosu was found in the urine and feces in 48 hours regardless of administration route (i.v., i.m. or p.o.).

Determination of aminophenol isomers in water samples by extraction and thin-layer chromatography densitometry

A TLC densitometric method for the determination of the aminophenol isomers in water samples has been developed. The aminophenols are first extracted into chloroform-isoamylalcohol (1:2) mixture. The extracted aminophenols are separated on a TLC plate and visualized by spaying solution of 2,4,7-trintro-9-fluorenone in acetone. The colored spots are scanned for light absorption or reflection and the amount of each aminophenol is evaluated.

Quantitation of the Triazine Herbicides Atrazine and Simazine in Water by Thin Layer Chromatography with Densitometry

Abstract A TLC-densitometric method for determination of the triazine herbicides atrazine and simazine in natural and tap water is described. Separation was carried out on silica gel G, followed by detection with silver nitrate and UV exposure. Alumina column cleanup was required for tap water. Recovery of samples fortified at 10 ppb was > 80%, and the relative standard deviation was better than 7.5%.