Densitometric Thin-Layer Chromatography of Protease Inhibitors in Pharmaceutical Preparations

JPC – Journal of Planar Chromatography – Modern TLC -     

Simultaneous Densitometric Determination of Ivermectin and Albendazole by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - This paper describes a validated high-performance thin-layer chromatography (HPTLC) method for the simultaneous determination of...     

Simultaneous Densitometric Determination of Rifampicin and Isoniazid by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatography (HPTLC) on silica gel 60 F254 TLC plates, with ethyl acetate-methanol-acetone-acetic...     

Simultaneous Densitometric Determination of Aspirin and Omeprazole by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A new, simple, accurate, and precise high-performance thin-layer chromatographic (HPTLC) method has been developed for the...     

A Spray Reagent for Identification of Amino Acids on Thin-Layer Chromatography Plates

JPC – Journal of Planar Chromatography – Modern TLC -     

A New Reagent for Identification of Amino Acids on Thin-Layer Chromatography Plates

JPC – Journal of Planar Chromatography – Modern TLC -     

Analysis of Sulfide Ions by Densitometric Thin-Layer Chromatography and use of TLsee Software

JPC – Journal of Planar Chromatography – Modern TLC - Simple and sensitive TLC-densitometry (method 1) and HPTLC with TLSee software (method 2) have been used for analysis of sulfide...     

Densitometric High-Performance Thin-Layer Chromatography Method for Toxigenity Testing of Alternaria alternata Strains Isolated from Foodstuffs

JPC – Journal of Planar Chromatography – Modern TLC - Alternaria alternata is an important mycotoxin-producing species that occurs on cereals, sunflower seeds, oilseed rape, tomato,...     

Physico-Chemical Properties of the Most Suitable Spray Reagent for Fluorescence Enhancement in Thin-Layer Chromatography

Abstract

In a fluorescence-enhancing method by spraying with a viscous organic solvent in thin-layer chromatography(TLC), the relationship between fluorescence enhancement and the properties of spray reagents was investigated, using 5-dimethylamino-1-naphthalene-sulfondimethylamide(DNS-DMA) as a fluorescent compound. A stuitable reagent should have two properties of giving high fluorescence intensity to a fluorescent compound and good transmigration from an adsorbent to the reagent medium, i.e., having the large product of relative fluorescence quantum number(RFQN) in the reagent solution and Rf value of the fluorescnet compound in TLC using the reagent as a developing solvent.

A mixture of Triton X-100 and chlofoform(2:8) showed the largest product for DNS-DMA, so that the mixture was expected to be the most suitable reagent, and DNS-amine fluorescences on a plate were enhanced about 100-fold practically. Standard curves for DNS-amines were linear in the range of 1 to 20 pmole per spot. The Triton X-100 mixture also was useful to other DNS-derivatives such as DNS-amino acids and DNS-peptides.

This selection of a suitable spray reagent was also discussed on other fluorescent compounds.     

Densitometric Simultaneous Quantification of Three Naphthoquinones from Impatiens balsamina L. Leaves by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - Impatiens balsamina belonging to family Balsaminaceae is commonly known as terda. The plant has extensive range of...     

Determination of Biphenyl in Citrus Fruits by Quantitative Thin-Layer Chromatography

Abstract

Residues of the fungicide biphenyl in citrus fruits have been determined by direct scanning of spots on phosphor-impregnated high performance silica gel TLC plates under UV light. Biphenyl was separated from fruit tissue by steam liquid-liquid extraction. Recoveries from spiked samples ranged from 92–99% at 100, 50, and 10 ppm levels. The precision of the TLC determination and overall procedure are shown to be adequate for residue analysis.     

Quantitative Determination of Propranolol in Human Serum by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatography (HPTLC) method for the quantification of propranolol in human serum is developed and...     

Application of Multiple-Gradient Thin-Layer Chromatography for the Quantitative Determination of Convallatoxine in Herba Convallariae

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatographic method with densitometric detection has been used to determine the convallatoxine...     

On-Plate Electrochemical Detection for Thin-Layer Chromatography

Abstract

Voltammetric electrochemical detection (ECD) coupled with thin-layer chromatography (TLC) was demonstrated for the quantification of trace organic compounds directly on a TLC plate. the electrochemical detection solvent was a thin layer of aqueous potassium chloride. For undeveloped plates, detection limits for p-anisidine and p-phenetidine were 10 ng and 13 ng, respectively. Linearity was demonstrated over nearly 2 orders of magnitude. After development, detection limits increased by approximately a factor of ten. Advantages of this method over other quantitative TLC methods include sensitivity, speed, simplicity, and cost. in addition, this method is selective for electrochemically active compounds. Major sources of experimental error include spot size reproducibility, working electrode placement, and supporting electrolyte film thickness.     

Quantitative Thin Layer Chromatography of Amino Acids Using Fluorescamine Reagent

Abstract

Calibration curves are presented for several different types of amino acids to illustrate the quantitation of these compounds by in situ fluorescence densitometry on thin layer plates.     

Experience with Quantitative Thin-Layer Chromatography in the Analysis of Drugs in Plasma

Abstract

A survey is presented concerning the possible techniques of quantitative thin-layer chromatography. Most of the possibilities mentioned have been used successfully in our laboratory for the determination of drugs and metabolites in plasma. With respect to our own experience, the advantages and disadvantages of quantitative thin-layer chromatography are discussed.

Although gas chromatography and high-performance liquid chromatography are more popular, quantitative thin-layer chromatography has a high potential in the analysis of drugs in samples of biological origin and should not be neglected in the development of an assay.     

Elucidation of Chemical Interactions between Crude Drugs Using Quantitative Thin-Layer Chromatography Analysis

To elucidate the interactions between crude drugs in Kampo medicines (traditional Japanese medicines), it is important to determine the content of the constituents in a cost-effective and simple manner. In this study, we quantified the constituents in crude drug extracts using thin-layer chromatography (TLC), an inexpensive and simple analytical method, to elucidate the chemical interactions between crude drugs. We focused on five crude drugs, for which quantitative high-performance liquid chromatography (HPLC) methods are stipulated in the Japanese Pharmacopoeia XVIII (JP XVIII) and compared the analytical data of HPLC and TLC, confirming that the TLC results corresponded with the HPLC data and satisfied the criteria of JP XVIII. (Z)-ligustilide, a major constituent in Japanese Angelica Root, for which a method of quantification has not been stipulated in JP XVIII, was also quantitatively analyzed using HPLC and TLC. Furthermore, Japanese Angelica Root was combined with 26 crude drugs to observe the variation in the (Z)-ligustilide content from each combination by TLC. The results revealed that combinations with Phellodendron Bark, Citrus Unshiu Peel, Scutellaria Root, Coptis Rhizome, Gardenia Fruit, and Peony Root increased the (Z)-ligustilide content. Quantifying the constituents in crude drug extracts using the inexpensive and simple TLC method can contribute to elucidating interactions between crude drugs in Kampo medicines, as proposed by the herbal-pair theory.     

High-Performance Thin-Layer Chromatography Combined with Densitometry for Quantitative Analysis of Phenolic Acids in Complex Mixtures

JPC – Journal of Planar Chromatography – Modern TLC - Protocatechuic acid and caffeic acid in plant extracts, both free and bound as glycosides and ester derivatives, have been...     

Validation of a High-Performance Thin-Layer Chromatographic Method,with Densitometric Detection,for Quantitative Analysis of Nebivolol Hydrochloride in Tablet Formulations

JPC – Journal of Planar Chromatography – Modern TLC - A quantitative densitometric high-performance thin-layer chromatographic method for determination of nebivolol hydrochloride in...