Showing papers on "Thin-layer chromatography published in 2003"
18 Apr 2003
TL;DR: This paper presents basic techniques, materials and apparatus theory and mechanism of thin-layer chromatography optimization in TLC sorbents and precoated layers in TLP, as well as applications of thin layer chromatography.
Abstract: Part 1 Principles and practice of thin-layer chromatography: basic techniques, materials and apparatus theory and mechanism of thin-layer chromatography optimization in TLC sorbents and precoated layers in TLC instrumental thin-layer chromatography gradient development in TLC overpressured layer chromatography detection, identification and documentation of chromatogen zones thin-layer chromatography coupled with mass spectrometry basic principles of optical quantitation in TLC preparative layer chromatography thin-layer radiochromatography rod TLC with flame ionization detection automation and robotics in planar chromatography. Part 2 Applications of thin-layer chromatography: amino acids and derivatives peptides and proteins antibiotics carbohydrates inorganics and organometallics enantiomeric separations lipids natural pigments pesticides pharmaceuticals and drugs phenols, aromatic acids and indoles nucleic acid derivatives steroids synthetic dyes toxins hydrophilic vitamins liphophilic vitamins.
599 citations
TL;DR: By checking this chemical inhibition on the TLC assay, the true enzyme inhibition could be distinguished from the false-positive chemical inhibition observed in the toluene extract of Nerine bowdenii in the course of isolation of active compounds.
Abstract: A method has been developed to determine the false-positive effects on acetylcholinesterase inhibition in the TLC assay based on Ellman's method. Various aldehydes and amines have been tested in order to determine whether the observed inhibition is due to a true enzyme inhibition or due to the inhibition of the reaction between thiocholine and 5,5'-dithiobis-(2-nitrobenzoic acid). 4-Dimethylaminobenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, diethylamine, triethylamine, triethanolamine and tyramine showed real enzyme inhibition, although their activity was about 10(3) times lower than that shown by galanthamine. Heptanal, decanal, cinnamaldehyde, anisaldehyde, benzaldehyde, hexylamine and tryptamine appeared to show a non-specific chemical inhibition. By checking this chemical inhibition on the TLC assay, the true enzyme inhibition could be distinguished from the false-positive chemical inhibition observed in the toluene extract of Nerine bowdenii in the course of isolation of active compounds.
158 citations
TL;DR: Aspartate N‐acetyltransferase (Asp‐NAT) activity was found in highly purified intact mitochondria prepared by Percoll gradient centrifugation as well as in the three subfractions obtained after the sucrose density gradient centrifUGation of Percoll purified mitochondria.
Abstract: Aspartate N-acetyltransferase (Asp-NAT; EC 2.3.1.17) activity was found in highly purified intact mitochondria prepared by Percoll gradient centrifugation as well as in the three subfractions obtained after the sucrose density gradient centrifugation of Percoll purified mitochondria; citrate synthase was used as a marker enzyme for mitochondria. The proportion of recoverable activities of Asp-NAT and citrate synthase were comparable in mitochondrial and synaptosomal fractions but not in the fraction containing myelin. Asp-NAT was solubilized from the pellet of the rat brain homogenate (26 000 g for 1 h) for the recovery of maximum activity and partially purified using three protein separation methods: DEAE anion exchange chromatography, continuous elution native gel electrophoresis and size-exclusion high performance liquid chromatography. Asp-NAT activity and the optical density pattern of the eluted protein from size-exclusion column indicated a single large protein (∼670 kDa), which on sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed at least 10 bands indicative of an enzyme complex. This seemingly multi-subunit complex Asp-NAT was stable towards ionic perturbations but vulnerable to hydrophobic perturbation; almost 95% of activity was lost after 10 mm 3-[(3-cholamidopropyl)dimethylammonia]-1-propanesulfonate (CHAPS) treatment followed by size-exclusion chromatography. Asp-NAT showed an order of magnitude difference in Km between l-aspartate (l-Asp, ∼0.5 mm) and acetyl CoA (∼0.05 mm). Asp-NAT showed high specificity towards l-Asp with 3% or less activity towards l-Glu, l-Asn, l-Gln and Asp-Glu. A model on the integral involvement of NAA synthesis in the energetics of neuronal mitochondria is proposed.
120 citations
TL;DR: A hyphenated chromatographic method was developed for a sensitive and precise determination of esterified sterols in olive oils and good sterol recoveries and repeatability were obtained.
98 citations
TL;DR: In this article, a sensitive and selective method for the determination of dopamine was described, where dopamine was oxidized by mercury(II) nitrate and the oxidation product was condensed with ethylene diamine to form a quinoxaline derivative which was strongly fluorescent.
97 citations
TL;DR: In this article, a monolithic structure of the stationary silica gel phase has been proposed for planar planar chromatography and the advantages of these plates are the short migration distances in the range of 1-3 cm, the short development times as well as the very low consumption of solvents as mobile phases in combination with high separation efficiency and sensitivity.
Abstract: Ultra thin-layer chromatography plates (UTLC) with a monolithic structure of the stationary silica gel phase open up a new dimension in modern planar chromatography. The extremely small layer thickness of 10 μm and the absence of any kind of a binder lead, in combination with the structure of this stationary phase, to new and improved properties of the UTLC silica gel plates. The advantages of these UTLC plates are the short migration distances in the range of 1–3 cm, the short development times as well as the very low consumption of solvents as mobile phases in combination with high separation efficiency and sensitivity.
35 citations
TL;DR: Conclusions on structure-lipophilicity relationships were drawn in terms of ring anellation, character and length of side chain, conformational preferences and moiety-solvent interactions, also supported by molecular mechanics studies.
33 citations
TL;DR: In this paper, the use of surfactants as modifiers of mobile and stationary phases in thin-layer chromatography is analyzed and the features of micellar and ion-pair versions of thin layer chromatography and the dynamic and static modifications of stationary phases with surfactant are considered.
Abstract: Data reported in the literature on the use of surfactants as modifiers of mobile and stationary phases in thin-layer chromatography are analyzed. The features of micellar and ion-pair versions of thin-layer chromatography and the dynamic and static modifications of stationary phases with surfactants are considered.
33 citations
TL;DR: In this paper, the content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g.
Abstract: The methanol, petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts were obtained by extraction of marigold flower (Calendula officinalis L.). The content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g. The content of total flavonoids, determined by UV spectrophotometric method according to Markham, was 5.13 mg/g. Qualitative determination of phenolic compounds in the extracts was performed by one- and two-dimensional thin-layer chromatography (TLC) procedures. The results of one- and two-dimensional TLC analyses showed that different flavonoids and phenolic acids were present in the investigated extracts. The greatest number of flavonoids (rutin, quercetin and some unidentified flavonoid glycosides) and phenolic acids (chlorogenic, caffeic, coumaric and vanillic acid) were deteminated in methanol extract. The influence of marigold extracts, in concentration range 0.6-1.2 mg/mL, on 2,2’diphenyl-1-picrylhydrazyl (DPPH) free radicals was investigated by electron spin resonance (ESR) spectroscopy. All extracts showed scavenging activity (SA) in the following order: ethyl acetate > n-butanol > methanol > water > chloroform > petroleum ether. The SA increased with increasing concentration of extracts. The ethyl acetate and nbutanol extracts exibited the most significant SA. These extracts in concentration of 1.2 mg/mL eliminated completely DPPH radicals. The lowest SA had chloroform and petroleum ether extracts (in concentration of 0.6 mg/mL SA=0%). The SA of marigold extracts is attributed to its hydrogen-donating ability and scavenging effect.
33 citations
TL;DR: The antibacterial property of C. nutans appears to have justified its use for the treatment of wounds, which are contaminated through bacterial infections, and was subjected to purification by repeated preparative thin layer chromatography.
Abstract: Ethanolic crude extracts from the roots of Chaptalia nutans, traditionally used in Brazilian folk medicine, were screened against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by using the disk diffusion test technique. S. aureus with 14 mm inhibition zone was considered susceptible. E. coli and P. aeruginosa without such a zone were considered resistant. As a result of this finding, the ethanolic crude extract was fractionated on silica gel column chromatography into five fractions. The ethyl acetate fraction was active against S. aureus and Bacillus subtilis. Further column chromatography separation of the ethyl acetate fraction afforded 30 fractions, which were assayed against S. aureus. Fractions 16 and 17 showed inhibition zones with S. aureus, indicating the presence of active compounds, and were subjected to purification by repeated preparative thin layer chromatography. The pure compound 7-O-b-D-glucopyranosyl-nutanocoumarin inhibited B. subtilis and S. aureus at concentrations of 62.5 µg/ml and 125 µg/ml, respectively. The antibacterial property of C. nutans appears to have justified its use for the treatment of wounds, which are contaminated through bacterial infections.
30 citations
TL;DR: In this article, a technique for the separation and quantitative determination of polyaromatic compounds with more than three aromatic rings is presented, which involves a multistep elution on a mixed (silica gel and caffeine-impregnated silica gel HPTLC plate).
Abstract: Improved methods for separation and quantitative determination of hydrocarbon types from gas oil have been developed, which were based on high-performance thin-layer chromatography with ultraviolet and fluorescence scanning densitometry using horizontal elution. One of the methods allows the separation, detection, and determination of alkanes and naphthenes to be carried out, using berberine-impregnated silica gel HPTLC plates, elution with n-hexane, and berberine-induced fluorescence detection at 365 nm. Another developed method allows total aromatics to be determined using silica gel HPTLC plates by elution with n-hexane and acetone, and UV detection. In turn, PACs over three aromatic rings can be determined on either silica gel or caffeine-impregnated silica gel HPTLC plates, elution with n-hexane, and selective detection using native fluorescence at 365 nm. Concentrations lower than 5 wt% can be determined using this technique. In addition, a technique for an efficient, baseline-resolved separation of a gas oil according to the number of aromatics rings (mono + di-, tri-, and polyaromatic compounds with more than three rings) is presented here. This technique involves a multistep elution on a mixed (silica gel and caffeine-impregnated silica gel HPTLC plate) using a counter-elution device, and UV detection.
TL;DR: The percentage of the active ingredient content of each tablet obtained by both procedures, was in the range of the stated amount except for one brand of diazepam tablets which contained approximately 23% less active ingredient than the minimum prescribed amount.
TL;DR: The enantiomeric resolution of certain 2-arylpropionic acids was achieved on thin silica gel plates impregnated with optically pure L-(-)-serine as chiral selector and was applied successfully to resolve commercial ampoules of ketoprofen dosage formulation.
TL;DR: Since the fluorescence from sialic acid is easily measurable on TLC plates and is sensitive over a wide range of sample concentration, the present method is applicable for quantitative determination of gangliosides.
Abstract: A new and simple fluorometric method for determine quantities of gangliosides ranging from pico- to nanomoles is reported. Spraying hydrochloric acid followed by a heating treatment, sugars (glucose, galactose, fucose, N-acetylgalactosamine, N-acetylglucosamine, N-acetylneuraminic acid (sialic acid)), gangliosides (GM1, GD1a, GT1b), and asialoganglioside (asialoGM1) on thin-layer chromatography plates produced fluorescence under 365-nm UV light. This fluorescence production of each sample was greatly dependent on the heating temperature. As sialic acid fluoresced readily at lower temperature (∼90 °C), we were able to distinguish sialic acid easily from other sugars tested. To determine gangliosides based on this sialic acid fluorescence, calibration curves for gangliosides were obtained by high-performance thin-layer chromatography and the image-analyzing system equipped with a CCD camera. The observed fluorescence images were analyzed using image-analyzing softwares, and the determined calibration curves...
TL;DR: In this paper, the chromatographic behavior of seven oral antidiabetic drugs (Chlorpropamide, tolbutamide, glibenclamide, metformin, pioglitazone, rosiglicazone and repaglinide) was investigated.
Abstract: The chromatographic behavior of seven oral antidiabetic drugs — chlorpropamide, tolbutamide, glibenclamide, metformin, pioglitazone, rosiglitazone, and repaglinide — has been investigated. Normal-phase chromatography was performed on silica gel and alumina layers with mixtures of chloroform, diethyl ether, and ethyl acetate as mobile phases. For more effective resolution aqueous ammonia or acetic acid was added to the mobile phases. Silica gel enabled better separation than alumina. Reversed-phase chromatography was performed on octadecyl-bonded silica gel (RP-18) with mixtures of acetonitrile or 2-propanol with phosphate buffer as mobile phases. The effect of pH on the separation of the drugs was also examined. For separation of these drugs reversed-phase chromatography was more effective than use of normal-phase mode.
01 Jan 2003
TL;DR: In this article, the authors examined the influence of different extraction solvents on the presence of secondary metabolites in the extracts by thin layer chromatography (TLC), determining the most suitable mobile phase for the plant extracts, and determining a most suitable detection method.
Abstract: The extracts of many plants used in traditional medicine contain curative agents that are used in many modern medicines. As part of the quest for potentially valuable plants of medicinal value, the plant species Phyllanthus amarus Schum. and Thonn. and Quassia amara L. were chosen based on ethno-pharmacological knowledge from Suriname, South America. Phyllanthus amarus (whole plant) was collected in the city Paramaribo and in the country, and Quassia amara (wood) was collected in the countryside of Suriname. The aim of this study was to optimize extraction methods in order to maximize the recovery of secondary metabolites in the crude extracts of P. amarus and Q. amara. This was accomplished by examining the influence of different extraction solvents on the presence of secondary metabolites in the extracts by thin layer chromatography (TLC), determining the most suitable mobile phase for the plant extracts, and determining the most suitable detection method. Ten grams of each species were extracted (w/v 1:10) with 50% methanol in water, 99% methanol, and 50% methanol in chloroform. Thin layer chromatography (TLC) was used to analyze the compounds in the plant extracts. In order to detect the most compounds, it was necessary to determine the optimal mobile phase (chloroform/methanol 9:1; 95:5; or 98:2) and most suitable detection method (I: UV-254 nm and Phosphomolybdic acid reagent; II: UV-365 nm and Dragendorff reagent; III: ethanolic sulfuric acid reagent; or IV: ethanolic sulfuric acid and UV-365 nm). For both plant species, crude extracts from methanol and chloroform-methanol yielded the highest number of fractions. Mobile phase chloroform/methanol 95:5 eluted the most fractions and had the best separation. Detection method I detected a wide variety
TL;DR: An attempt was made to quantify withaferine A in herbal extract and polyherbal formulations produced from Withania somnifera by high performance thin layer chromatography (HPTLC), which was found to be reproducible, accurate, and precise.
Abstract: Withania somnifera has been used in Ayurvedic medicine for treatment of depression and inflammation, and as an aphrodisiac. It contains many phytochemicals such as Withaferine A, withanine, anahygrine, tropine, and withanolides. Of these, withaferine A is considered to be the most active compound. Withaferine A was estimated in herbal extract and polyherbal formulations by high performance thin layer chromatography (HPTLC). As there is no official HPTLC protocol for quantitation of the above phytochemicals, an attempt was made to quantify withaferine A in herbal extract and polyherbal formulations produced from Withania somnifera. Precoated silica gel G (aluminium backed) plates were used as stationary phase and toluene:ethyl acetate: formic acid (50 : 15 : 5) was used as mobile phase. Detection and quantification were performed by densitometry at λ 213 nm. The linear range was 1 μg to 3 μg. This HPTLC method was found to be reproducible, accurate, and precise.
TL;DR: In this article, the selectivities of TLC systems have been compared by use of correlations between R F(II) and R F (I) values (by analogy with two-dimensional TLC).
Abstract: The selectivities of TLC systems have been compared by use of correlations between R F(II) and R F(I) values (by analogy with two-dimensional TLC). The greatest spread of spots, indicative of individual selectivity, was obtained for combination of non-aqueous mobile phases comprising a weakly polar diluent (heptane) and a polar modifier (tetrahydrofuran) on silica, and for aqueous mobile phases comprising a polar solvent (methanol) in water on water-wettable octadecyl silica (RP-18W). A good spread of spots was also obtained for pairs of normal-phase systems with hepatane-ethyl acetate mobile phases and reversed-phase systems with water-dioxane mobile phases, both on polar cyanopropyl-bonded layers. The correlation of R F values in normal- and reversed-phase systems were used for practical separation of a mixture of ten urea herbicides by two-dimensional thin-layer chromatography on cyanopropyl-bonded polar adsorbents and by use of a layer comprising two zones — a narrow zone of silica adjacent to a wide ...
TL;DR: Two-dimensional planar chromatography (2D TLC) on cellulose layers, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography(HPLC) have been used for purification, separation, and identification of the phenolic acids in the foliage and fruits of Peucedanum tauricum Bieb.
Abstract: Two-dimensional planar chromatography (2D TLC) on cellulose layers, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (HPLC) have been used for purification, separation, and identification of the phenolic acids in the foliage and fruits of Peucedanum tauricum Bieb. ( Umbelliferae = Apiaceae ). Methanolic extracts of the foliage and fruit were purified and the free phenolic acids fractions were isolated by means of the classical method of Ibrahim and Towers . Hydrolysis of the esters and glycosides was performed by the method of Schmidtlein and Herrmann . Isolated fractions containing phenolic acids were investigated by comparison with standards, by means of analytical 2D TLC on cellulose layers, by use of derivatization reagents (gaseous NH 3 , 3% FeCl 3 and diazotized sulfanilic acid in 20% sodium carbonate solution), and by RP HPLC with isocratic elution (mobile phase methanol-water, 20:80 ( v / v ) containing 1% ( v / v ) acetic acid) and UV spectroscopy (by means ...
TL;DR: A new simple, precise, rapid, and selective high-performance thin-layer chromatography (HPTLC) method has been developed for the analysis of finasteride in pharmaceutical formulations that uses loratadine as an internal standard.
Abstract: A new simple, precise, rapid, and selective high-performance thin-layer chromatography (HPTLC) method has been developed for the analysis of finasteride in pharmaceutical formulations. The method uses loratadine as an internal standard. The stationary phase was silica gel 60F 254 prewashed with methanol; chloroform-ethyl acetate, 6 + 4 (v/v) was used as mobile phase. Detection and quantification were performed densitometrically at λ = 228 nm. The linear range of the analysis was 0.2-2.0 pg and the percentage recovery was 101.8%.
TL;DR: Dansyl chloride (DNS-Cl) is a sulfonyl chloride compound which is utilized as a fluorescent probe for quantitative analysis or structural studies of complex molecules and the dansylation of carboxyl compounds was effective.
TL;DR: Investigation on presence of coumarins and flavonoids in domestic plant material that have wide everyday usage and method of thin layer chromatography has been shown as very reliable.
Abstract: Drugs, natural medicinal plant, animals and mineral materials, have a large and various application in official pharmacy and medicine. Carriers of multilateral pharmacological effects that those drugs shown, are chemically define as active components that are present in them. Methods of qualitative and quantitative analysis are used for the chemical investigation of components that drugs contain. Method of thin layer chromatography has been shown as very reliable. According to the chemical investigation of single drugs, it is possible to define a group of compound or single compound comparing them with standards. Relating to the usage of method of thin layer chromatography, it has been carried out investigation on presence of coumarins and flavonoids in domestic plant material that have wide everyday usage. Coumarins and flavonoids from the point of view of chemical belonging are phenol derivatives with important pharmacological effects. Applying method of thin layer chromatography, it is detected presence of coumarins and flavonoids substances in plant material that has been tested. Anethi graveolens fructus et folium (fruit and leaf of dill), Anethum graveolens L., Apiaceae, Avenae sativae fructus (fruit of oats), Avena sativa L., Poaceae and Asperulae odoratae herba (sweet woodruff), Asperula odorata L., Rubiaceae. Chromatograms are developed in systems cyclohexane-ethylacetat (13:7) and toluene-ether (1:1) saturated with 10% acetic acid, and visualisation by observing on UV lamp (254 and 366 nm), spraying with reagents KOH (10% ethanol solution) and diphenylboryloxyethylamine (1% methanol solution).
TL;DR: In this paper, the authors used thin layer chromatography (TLC) to detect the catalytic system [Ir(COD)Cl]2/PPh3 for isomerisation of diolefinic substrates instead of the expected ring closing metathesis reaction.
Abstract: Thin layer chromatography (TLC) represents a fast and inexpensive alternative to NMR spectroscopy or analytical methods based on chromatography for the detection of unexpected products in organometallic combinatorial catalysis. This screening test led to the detection of the catalytic system [Ir(COD)Cl]2/PPh3 for isomerisation of diolefinic substrates instead the expected ring closing metathesis (RCM) reaction.
TL;DR: In this paper, aflatoxin M1 (AFM1) analysis in milk and egg matrixes were assayed for AOAC official and modified methods with detection and quantification by thin layer chromatography (TLC) and HPTLC.
Abstract: Milk and egg matrixes were assayed for aflatoxin M1 (AFM1) and B1 (AFB1) respectively, by AOAC official and modified methods with detection and quantification by thin layer chromatography (TLC) and high performance thin layer chromatography (HPTLC). The modified methods: Blanc followed by Romer, showed to be most appropriate for AFM1 analysis in milk. Both methods reduced emulsion formation, produced cleaner extracts, no streaking spots, precision and accuracy improved, especially when quantification was performed by HPTLC. The use of ternary mixture in the Blanc Method was advantageous as the solvent could extract AFM1 directly from the first stage (extraction), leaving other compounds in the binary mixture layer, avoiding emulsion formation, thus reducing toxin loss. The relative standard deviation (RSD%) values were low, 16 and 7% when TLC and HPTLC were used, with a mean recovery of 94 and 97%, respectively. As far as egg matrix and final extract are concerned, both methods evaluated for AFB1 need further studies. Although that matrix leads to emulsion with consequent loss of toxin, the Romer modified presented a reasonable clean extract (mean recovery of 92 and 96% for TLC and HPTLC, respectively). Most of the methods studied did not performed as expected mainly due to the matrixes high content of triglicerides (rich on saturated fatty acids), cholesterol, carotene and proteins. Although nowadays most methodology for AFM1 is based on HPLC, TLC determination (Blanc and Romer modified) for AFM1 and AFB1 is particularly recommended to those, inexperienced in food and feed mycotoxins analysis and especially who cannot afford to purchase sophisticated (HPLC,HPTLC) instrumentation.
22 Aug 2003
TL;DR: In this paper, the transglycosylation reaction was conducted with maltotriose and sucrose as the donor and acceptor, respectively, and the presence of various sucrose transfer products was confirmed by thin layer chromatography (TLC) and high performance anion exchange chromatography.
Abstract: To develop a new transfer product of sucrose, sucrose was modified to maltosyl-sucrose using the transglycosylation activity of maltogenic amylase from Bacillus stearothermophilus (BSMA). The transglycosylation reaction was conducted with maltotriose and sucrose as the donor and acceptor, respectively. The presence of various sucrose transfer products was confirmed by thin layer chromatography (TLC) and high performance anion exchange chromatography (HPAEC). The sucrose transfer products were isolated by alkali-degradation followed by charcoal column chromatography using 20% (v/v) ethanol, then purified by ion exchange and Biogel P-2 gel permeation chromatographies. The structures of the major transfer products were determined to be 6G-α-maltosyl-sucrose (maltosyl-sucrose 1) and 6F-α-maltosyl-sucrose (maltosyl-sucrose 2) by LC-MS and 13 C NMR. The mixture of maltosyl-sucrose 1 and 2 showed low sweetness, high hygroscopicity, low Maillard reactivity, and high acid and heat stability. Furthermore, it had an inhibitory effect on mutansucrase and water-insoluble glucan formation. These results indicated that the mixture of maltosyl-sucrose 1 and 2 is a suitable sugar substitute useful for various food products.
Journal Article•
TL;DR: In this article, the application of iodine-azide reaction for the determination of thiouracils in thin-layer chromatography and high-performance thin layer chromatography is described, and the developed plates were sprayed with a freshly prepared mixture of sodium azide, adjusted to a proper pH, and starch solution, and exposed to iodine vapour for 5 s.
TL;DR: An endeavor has been undertaken to resolve the color problem of thin layer chromatography plates by use of two different spray reagents, which produce different distinguishable colors with amino acids and with high sensitivity.
Abstract: The detection or identification of amino acids has immense importance in evaluation of protein structure, for determining their occurrence in the free state in natural products, and for the determination of the C-terminal units of degraded proteins. A variety of specific and non-specific reagents [1–16] has been used to identify amino acids on thin layer chromatography (TLC) plates. Among the reagents used so far, ninhydrin is still widely used because of its remarkably high sensitivity [2]; it does, however, gives same purple color with all amino acids except proline and hydroxyproline which produce yellow colors. An endeavor has been undertaken to resolve this color problem by use of two different spray reagents. These reagents produce different distinguishable colors with amino acids and with high sensitivity.
TL;DR: In this article, an HPTLC method was developed to give qualitative and quantitative information on red wine pigments using solid-phase extraction (SPE) on C 18 cartridges and isocratic elution with methanol-water-trifluoracetic acid.
Abstract: An HPTLC method has been developed to give qualitative and quantitative information on red wine pigments. The samples are prepared by solid-phase extraction (SPE) on C 18 cartridges. Analytical determination is done by chromatography on C 18 silica gel plates with isocratic elution with methanol-water-trifluoracetic acid, 55 + 45 + 1 ( v/v ). This method leads to the clear separation of the three classes of Vitis vinifera anthocyanins with good statistical repeatability and reproducibility for wines of different vintages. It also enables evaluation of the amount of polymeric pigments in red wines.