Jpc-journal of Planar Chromatography-modern Tlc最新文献

Millettia pinnata (Fabaceae) is a multipurpose legume tree native to Southeast Asia. In this study, the methanolic extract of M. pinnata stem bark powder was utilised for the extraction, phytochemical screening and characterisation of isolated fractions. The high-performance thin-layer chromatography (HPTLC) method was created to standardise stem bark utilising karanjin as an active chemical marker. Column chromatography was used to isolate karanjin along with other chemical markers, and HPTLC‒mass spectrometry (HPTLC‒MS) was used for confirmation. The HPTLC technique for karanjin was validated according to the International Council for Harmonisation (ICH) Q2(R1) standard and was determined to be a reliable, accurate and precise approach. The new method has substantial promise for quantifying karanjin from M. pinnata stem bark. The current study aims to quantify, isolate,= and identify the chemical marker karanjin from M. pinnata stem bark. The proposed HPTLC‒densitometric method may be used for routine quality control analysis for the quantification of karanjin quantification from M. pinnata stem bark.

Planar bioassays are powerful, sustainable tools for nontargeted detection of hazardous compounds in complex samples. They provide more information on a sample than corresponding in vitro assays and are more sustainable in terms of plastic material and solvent consumption. However, instrument investment costs for high-performance thin-layer chromatography are high. Hence, the question arose of whether the sophisticated sensitive planar genotoxicity bioassay could be performed manually without instrumentation under simple conditions. Cheaper plate types were studied as well as manual application of the samples, cell suspension, and substrate solution. As a result, genotoxic compound zones were detected as rose-colored or orange fluorescent resorufin end-product formed upon contact of the genotoxins in tested perfume and packaging materials with a genetically modified Salmonella Typhimurium strain. The simple performance was found to be possible for low sample application volumes. Knowledge on neutral pH value and thickness of the adsorbent layer were further key aspects. Manual spraying was found to be superior to manual immersion if excess liquid was avoided. For high sample volumes and a higher level of standardization, the open-source 2LabsToGo system was proposed as excellent option for low investment costs. Its very low instrumental footprint and the straightforward prioritization strategy help analytical chemistry to balance between technology and nature/ecology to reduce the instrumental footprint and planetary overshoot.

Synthetic cannabinoids (SCs) exemplify the largest group of drugs of abuse detected by the USA and other countries through early warning systems of drugs of abuse. They are generally sprayed on aromatic or other “natural herbal mixtures” with the aim of simulating the effect of cannabis, and are sold as “herbal smoking blends” or “herbal incenses” under brand names such as “Spice” or “K2.” In this context, we implemented a fast and reliable method for the analysis of SCs CP-47,497, AM2201, and JWH-018 in seized samples by high-performance thin-layer chromatography (HPTLC), offering comparative advantages such as low cost and rapid results, with low use of solvents or other chemicals and reagents.

The operational conditions for applying solutions of a dye (Oil Red) dissolved in acetone and methanol to a chromatographic plate are described. These solvents are characterized by high elution power, but they are very good solvents of various substances, so they are often used for this purpose in laboratory practice. However, their unfavorable feature, due to their use as solvents of samples placed on a chromatographic plate, is their high elution strength, which contributes to an increase of the diameter of the starting spot. To eliminate or reduce this unfavorable effect, this research used operational factors such as reduced speed of applying the test solution to the chromatographic plate, increased temperature (40 and 55 °C), and reduced pressure by 0.15 bar relative to atmospheric pressure. All this accelerated the evaporation of the solvents and led to smaller application spots. Studies have shown that the above-mentioned operational factors performed using equipment available in a regular laboratory contribute to a significant reduction of the starting spot despite the use of sample solvents with high elution strength.

Abstract

The retention behavior of 10 previously synthesized α,β-unsaturated acids that exhibited antimicrobial activity was studied using 12 reversed-phase thin-layer chromatography (RP-TLC) systems. The mobile phases consisted of three solvent combinations (methanol‒water, acetonitrile‒water, and acetone‒water) in four different ratios (50:50, 60:40, 70:30, and 80:20, V/V). The chromatographic parameters ({R}_{M}^{0}) , a, and C₀ were calculated for each system. The lipophilicity parameters of the tested compounds were predicted using various computational methods. The acetone‒water system demonstrated the highest correlation coefficients between the chromatographic and calculated lipophilicity parameters, which makes it the most suitable for evaluating the lipophilicity of the tested compounds. This system successfully reflected the effect of the lipophilic properties of the compounds on their retention behavior. To elucidate the retention mechanisms, the molecular properties of the tested compounds were calculated and a genetic algorithm was used to identify the properties with the greatest influence on the retention behavior. The interpretation of these descriptors revealed structural and physicochemical properties crucial for the behavior of the tested compounds. In addition, the pharmacokinetic properties of the compounds were estimated using in silico methods. The observed correlation between the retention mechanism and physicochemical properties affecting membrane transport and physiological binding ability highlights the applicability of RP-TLC conditions for rapid profiling of newly synthesized α,β-unsaturated acids.

Abstract

Typical derivatization reagents for saccharides in high-performance thin-layer chromatography, like 2-naphthol sulfuric acid, aniline diphenylamine orthophosphoric acid, or p-aminobenzoic acid, generally detect both reducing and non-reducing saccharides. A new reagent was found with ethylamine, specifically reacting with reducing saccharides on normal-phase silica gel plates, resulting in strongly fluorescent zones after heating the plate at 150 °C for 15 min. In contrast, non-reducing saccharides generally did not reveal fluorescent signals tested with 26 different saccharides. Optimal chromatographic separation was achieved with a mixture of 2-propyl acetate, methanol, and water with 1 mg/mL natural product reagent A when the plate was twofold developed. The high sensitivity of the ethylamine derivatization was shown with mean limits of detection and quantification of 10 and 30 ng per zone, respectively, calculated by different methods for selected mono- and disaccharides. The developed method has exemplarily been used for the digestion control of starch by α-amylase, the determination of lactose in lactose-free milk, and for the quantitative and qualitative study of honey. The analysis of honey gave an excellent example of the advantageous consecutive derivatization with ethylamine and aniline diphenylamine orthophosphoric acid reagent as reagent sequence to detect the coelution of reducing and non-reducing saccharides.

The inorganic sulfur compounds that are used as pulping agents in the production of pulp and paper from wood are converted into a variety of sulfur species during processing. How sulfur is allocated to different streams and products in a pulp mill is relevant for efficient mill operation and to avoid harmful emissions. Pulping liquors are a highly challenging and potentially destructive sample matrix. We describe a thin-layer chromatographic method for the direct quantification of elemental sulfur in pulping liquors. The liquors are spotted (not sprayed!) directly onto the plate without prior purification, extraction, or workup. Sulfur is then eluted with cyclo-hexane and detected by densitometry at 285 nm or fluorescence quenching close to the solvent front. The method was validated for a calibrated range from 60 to 2000 ng sulfur on plate. The limit of detection was determined at 20 ng; measurement uncertainty was about 20%. With this method, 27–54 mg/L elemental sulfur were found in Kraft pulping liquors, which corresponds to 0.24–0.48% of the total sulfur in these samples.

Hispidulin has been isolated from the leaves of Clerodendrum philippinum and identified with the help of physical and spectroscopic data. A high-performance thin-layer chromatographic (HPTLC) method has been developed and validated for its accurate estimation in different plant parts of C. philippinum. Thin-layer chromatographic (TLC) analysis was performed on HPTLC plates by use of a ternary mobile phase consisting of chloroform‒methanol‒formic acid (9:1:0.1, V/V). It was quantified at the wavelength of its maximum absorbance at 267 nm, with a linear response in the range of 100‒500 ng per spot. The method was validated according to the International Council for Harmonisation (ICH) guidelines. The developed method was found to be more highly sensitive than the previously reported methods and gives consistent results when applied for the postchromatographic estimation of hispidulin. The developed method is very accurate, precise, and has been successfully applied for the analysis of hispidulin in C. philippinum, and also can be used for its quality control and standardization.

Eulophia nuda Lindl. is an edible orchid having numerous folklore claims in India. The aim of the present study was the quantification of amino acids and sugars in this species by using a validated high-performance thin-layer chromatography method. Several sets of solvent systems were tried; based on the separation and peak area, a fingerprint of amino acids and sugars was developed in the tertiary solvent of n-butanol–acetic acid–water at variable concentrations. Densitometric quantification of amino acids and sugars was done at 500 nm and 450 nm. The results suggest the presence of l-arginine monohydrochloride, dl-aspartic acid, glutamic acid, and leucine amino acid in this species. Besides, the corm also contains sucrose and fructose. The retention factor (R_F) of amino acids, viz., l-arginine monohydrochloride, dl-aspartic acid, glutamic acid, and leucine, was 0.049 ± 0.001, 0.164 ± 0.01, 0.261 ± 0.02, and 0.572 ± 0.01, respectively, and of sugars (sucrose and fructose) was 0.35 ± 0.03 and 0.479 ± 0.02. The developed method was found to be linear in the concentration range of 50–250 ng spot⁻¹ for amino acids and 200–600 ng spot⁻¹ for sugars. Intraday (reproducibility) and interday (repeatability) precision were within the acceptance limits of International Council for Harmonisation (ICH) guidelines. The recovery of amino acids and sugars ranged from 99.49% to 100.87% and from 99.73% to 100.49% for the developed method. Among the quantified amino acids, dl-aspartic acid (10.46 ± 0.12 µg mg⁻¹) showed the highest content in this species, whereas the content of fructose (11.07 ± 0.26 µg mg⁻¹) was higher than that of sucrose.

A high-performance thin-layer chromatography (HPTLC) method was developed for the estimation of zingerone from ginger tablets. A CAMAG Linomat 5 sample applicator was used for the application of the sample. Chromatographic separation of the marker was performed over thin-layer chromatography (TLC) plates precoated with silica gel 60 F₂₅₄ using toluene‒ethyl acetate (6:4, V/V) as the mobile phase via a linear ascending technique in a twin-trough chamber. Detection and quantification were carried out at a wavelength of 280 nm using a CAMAG TLC Scanner 4. This method showed good peak symmetry for the marker with a retention factor (R_F) of 0.43 ± 0.03 for zingerone. The calibration curve was linear in the range of 200‒2000 ng/spot for zingerone, and the correlation coefficient (r²) was 0.9836. The method was validated according to the International Council for Harmonisation (ICH) Q2(R1) guidelines for linearity, limit of detection, limit of quantification, precision, accuracy (recovery), and robustness. In conclusion, the developed method is simple, reliable, and specific for the identification and quantification of zingerone.