Chromatography Plates Research Articles

Ultrafast Solid-Phase Oxidation of Aldehydes to Carboxylic Acids by Atmosphseric Plasma Treatment.

Although atmospheric plasma treatment is an industrially widespread, scalable, and environmentally friendly method, it has been generally used for surface modification, decontamination, or sterilization. In this paper, a novel, sustainable, green, and ultrafast oxidation method is described for aldehydes on a preparative thin-layer chromatographic plate as a solid support. The plasma treatment has proven to be suitable for producing the corresponding carboxylic acids by using only air as a reactant source under mild reaction conditions, while the isolation of the products is also directly integrated into the oxidation process. Extensibility to other reaction types is not explored yet, but we are sure that this novel synthesis conception carries a lot of possibilities.

Comparison of the Limit of Detection of Paracetamol, Propyphenazone, and Caffeine Analyzed Using Thin-Layer Chromatography and High-Performance Thin-Layer Chromatography

TLC (thin-layer chromatography) and HPTLC (high-performance thin-layer chromatography) in normal (NP) and reversed (RP) phase systems were combined with densitometry to analyze caffeine, propyphenazone, and paracetamol. This work aims to check whether comparable limit of detection (LOD) values can be obtained on TLC and HPTLC plates. Analyses were performed on five (NP) or four (RP) different stationary phases (chromatographic plates), testing, in both cases, three mobile phases. It is shown that by using both TLC and HPTLC plates, it is possible to develop chromatographic conditions that enable the detection of compounds analyzed in amounts ranging from a dozen to several dozen µg/spot. In the RP system, lower LOD values for all tested compounds were obtained using TLC than HPTLC. However, performing analyses in the NP, similar (of the same order) LOD values were obtained for caffeine, propyphenazone, and paracetamol when using both TLC and HPTLC plates. For example, during the NP-HPTLC analysis using silica gel 60F254 plates (#1.05548) and mobile phase B (n-hexane—acetone—ammonia, 25:25:0.5, v/v/v), LOD values for caffeine, propyphenazone, and paracetamol were 0.010, 0.046, and 0.030 μg/spot, respectively. During NP-TLC analysis using silica gel 60F254 (#1.05554 plates) and the mobile phase C (chloroform—toluene—ethyl acetate—methanol—80% acetic acid, 18:18:7.5:6:0.3, v/v), the values of LOD were 0.054, 0.029, and 0.016 μg/spot, respectively. During RP-TLC analysis using TLC RP-18F254 plates (#1.05559) and mobile phase F (methanol-water, 40:10, v/v), the LOD values were 0.019, 0.024, and 0.053 μg/spot, respectively. Therefore, for economical reasons, TLC plates should be recommended for analyses of caffeine, propyphenazone, and paracetamol, which are several times cheaper than HPTLC plates.

Application High-Performance Thin-Layer Chromatography with Controlled Eluent Velocity to Determine Fingerprints of Various Poplar Species Buds Extracts: Optimization of Operating Variables

The study used the prototype device enabling the development of isocratic and gradient thin-layer chromatograms with controlled eluent velocity to obtain fingerprints of extracts from buds of various poplar species. This equipment can deliver an eluent to virtually any place on the adsorbent layer of the chromatographic plate. Moreover, the composition of a mobile phase can be easily modified even when the chromatogram is developing. This paper shows the effect of various operating variables of the prototype in a normal phase system, e.g., eluent velocity and composition, on the chromatographic behavior of the mixture. The prototype’s results were compared to conventional TLC development in horizontal DS chambers. The UV light (366 nm) was used to detect the solute zones and document both systems. The results prove that the prototype device has great potential in plant material standardization. The mobile phase gradient improves the separation of the bands of strongly retained solutes. Additionally, this fact does not enhance the blurring of low-retained bands.

Sensitive and Cost-Effective TLC-Densitometric Method for Determination of Metronidazole and Tinidazole in Tablets

A sensitive, easy-to-use, fast, and cost-effective TLC-densitometric method was developed for the separation of metronidazole, secnidazole, ornidazole, tinidazole, and 2-methyl-5-nitroimidazole and for the determination of metronidazole and tinidazole in Metronidazole Polpharma and Tinidazolum Polpharma tablets. Analyses were performed on chromatographic plates precoated with silica gel 60F254 using chloroform + methanol + diethylamine in a volume ratio of 9:1:1 as the optimal mobile phase. The method has been validated. The intraday and interday precision values for the three different concentrations ranged from 0.99% to 1.48% and 0.89% to 1.76%, and the precision values ranged from 1.13% to 2.48% and 0.95% to 2.49% for metronidazole and tinidazole, respectively. The limit of quantification (LOQ) was 0.036 and 0.066 µg/spot for metronidazole and tinidazole, respectively. The mean recovery was 103.1% and 100.6% for metronidazole and tinidazole, respectively. The content of metronidazole and tinidazole in tablets in relation to the content declared by the manufacturer was 101.3% and 99.8%, respectively. The obtained results were verified using the pharmacopeial method. The presented method is fast, sensitive, precise, selective, accurate, and robust. It allows for the analysis of several samples on one chromatography plate at the same time.

Optimization of a Rare Earth and Aluminum Leaching Process from Weathered Crust Elution-Deposited Rare Earth Ore with Surfactant CTAB

Ammonium sulfate is typically employed as a leaching agent in the in situ leaching of weathered crust elution-deposited rare earth ore. However, it is associated with challenges such as low efficiency in mass transfer for rare earth (RE) leaching, high usage of the leaching agent, and prolonged leaching duration. To address the issues mentioned above, the surfactant cetyltrimethyl ammonium bromide (CTAB) was compounded with 2% ammonium sulfate to form a leaching agent in this paper. The effects of CTAB concentration, temperature, pH, and leaching agent flow rate on the rare earth (RE) and aluminum (Al) leaching mass transfer process from RE ore were investigated using chromatographic plate theory. The results revealed that CTAB addition improved the RE mass transfer process while moderately inhibiting the Al mass transfer efficiency. Increasing the temperature and pH of the leaching solution led to higher theoretical plate numbers for RE and Al leaching, lowered theoretical plate height (HETP), and enhanced leaching mass transfer efficiency. However, under high temperature and alkaline conditions, the mass transfer efficiency begins to decrease, indicating that high temperature and alkaline conditions are not conducive to the synergistic enhancement of RE and Al leaching by CTAB. Considering that clay minerals have good pH buffering properties, adjusting the pH of the leaching solution during rare earth ore leaching operations was deemed unnecessary. The optimal mass transfer conditions for leaching RE and Al were identified as 2% ammonium sulfate concentration, 0.00103 mol/L CTAB concentration, pH range of 5.2–5.5 for the leaching solution, 0.6 mL/min leaching solution flow rate, and room temperature. The rare earth leaching mass transfer effect could be enhanced during summer operations.

A solid-liquid microextraction approach from a spot in an adsorbent layer of a chromatographic plate

A new approach to extracting substances from a spot on a chromatographic plate for subsequent liquid chromatography-mass spectrometry analysis is described. This method involves extraction in a solid phase (an adsorbent layer of a chromatographic plate) - a liquid system using a simple device. For a single extraction of six selected coccidiostats from the adsorbent layer on the chromatographic plate with silica gel, 50 µL of methanol was used for 5 min. The data from the extraction experiments and liquid chromatography-mass spectrometry measurements demonstrated a good correlation between the ratio of the peak areas of the coccidiostats to the internal standard and the concentration of the substances in the range of two orders of magnitude. The coefficients of determination for the mentioned correlations range from 0.962 to 0.999. Moreover, the repeatability and reproducibility, expressed as the percentage values of relative standard deviation, do not exceed 7.5 % for any of the coccidiostats.

Screening method for the analysis of Rhodamine B in chili powder

Rhodamine B is a synthetic dye known to enhance the visual appearance of chili powder. Due to its toxicity and carcinogenicity, chromatographic methods have been developed to monitor its presence in adulterated chili powder, but their assays are laborious, time consuming and expensive for screening purposes. The present studies propose an alternative for screening Rhodamine B in chili powder samples. The method combines thin layer chromatography (TLC) to solid surface room-temperature fluorescence spectroscopy. The scrape-dissolution procedure common to the instrumental analysis of TLC procedures was replaced with a fiber optic probe coupled to a commercial spectrofluorometer. The determination of Rhodamine B on the chromatographic plate is based on its retardation factor and maximum excitation and emission wavelengths. The limit of detection (1.9 ng.mL−1) and the limit of quantitation (5.2 ng.mL−1) are well below the usual contamination of Rhodamine B in adulterated foods.

COMPARATIVE CHROMATOGRAPHIC AND SPECTRAL STUDY OF THE ALKALOID COMPOSITION OF THE BIOMASS OF TISSUE CULTURE AND THE HERB OF GLAUCIUM FLAVUM

Introduction. The culture of plant cells and tissues is an effective technology for obtaining various secondary metabolites, including for use in the pharmaceutical industry. Compounds synthesized in callus and suspension cultures may be identical to plant ones, and the yield of secondary metabolites, in some cases, exceeds plant sources. In this regard, yellow hornpoppy (Glaucium flavum Crantz.) is of great interest, containing glaucin, which has a unique antitussive effect and is a source of a number of medications. The purpose of this study is a comparative phytochemical study of the alkaloid composition of the tissue culture and the herb of Glaucium flavum. Material and methods. Callus tissue cultures of yellow hornpoppy yellow hornpoppy (Glaucium flavum Crantz.) were obtained in the laboratory of the Institute of Pharmacy of Kazan State Medical University. The herb of the Glaucium flavum cultivated on the territory of the Botanical Garden of Samara University was collected during the flowering period of plants in 2021. A comparative study of the alkaloid composition of the callus culture and the herb of Glaucium flavum was carried out by methods of luminescent microscopy on an Altami LUM-2 microscope (Russia), thin-layer chromatography (TLC) on Sorbfil-PTSH-AF-A-UV plates, as well as spectrophotometry. A mixture of solvents n-butanol-acetic acid-water 4:1:2 was used as a solvent system. The detection of separated substances was carried out by scanning chromatographic plates in UV light at a wavelength of 366 and 254 nm, followed by the manifestation of Dragendorf reagent. The identification of the isolated glaucin hydrochloride was carried out on the basis of UV, 1H-NMR, 13C-NMR spectroscopy data. 1H NMR spectra were obtained on the "JNM-ECX 400" device (399.78MHz), 13C NMR spectra were obtained on the "JNM–ECX 400" device (100.52 MHz). The spectra were recorded using a Specord 40 spectrophotometer (Analytik Jena AG, Germany) in the wavelength range of 190-500 nm. Results. During the luminescent analysis of the tissue culture of the Glaucium flavum Crantz., as well as intact plants, the type of luminescence characteristic of isoquinoline alkaloids was noted. Using TLC analysis, isoquinoline alkaloids, including glaucin, were found in samples of callus cultures and the aerial parts of Glaucium flavum, however, a lower glaucin content was noted in the sample of the callus culture compared to that of the intact plant. The spectrophometric analysis of the studied samples showed that the nature of the absorption curve in intact plants and crops of the so-called Glaucium flavum has both common and distinctive features. The UV spectrum of water-alcohol extraction from a sample of Glaucium flavum tissue culture has a similar spectrophotometric profile, however, it contains only one absorption maximum (288 nm), coinciding with that of the UV spectrum of water-alcohol extraction from the herb of this plant. Conclusions. Therefore, the final conclusion regarding the content of glaucin in the studied samples can be made only during the preparative isolation of substances from the biomass of Glaucium flavum using column chromatography

Silver-doped graphite oxide composites used as antimicrobial agents against Staphylococcus aureus, Escherichia coli and Tatumella terrea evaluated by direct TLC bioautography

Silver-doped graphite oxide composites presented mixed Ag and Ag2O crystalline phases accompanied by C/O and ID/IG average ratios of 2.13 and 1.16, associated with a good oxidation degree and high structural disorder or defects in the carbon material, respectively. The low-silver-doped GrO composite showed homogenous silver particle dispersion and a low particle size distribution (96 nm). However, high-silver-doped GrO composites generated materials with high relative crystallinity, silver particle agglomeration, and Ag metal phase promotion. At 3 and 5 mg ml−1 per chromatographic plate, the silver-doped graphite oxide composites were tested by direct TLC bioautography against Staphylococcus aureus, Escherichia coli, and Tatumella terrea microorganisms, where the minimum inhibitory concentration was 3 mg ml−1 per chromatographic plate. At 3.0 mg ml−1 per chromatographic plate, high-silver-doped GrO composites exhibited a 39%, 3.2-fold, and 83% higher retention factor (R f ) compared with the composites with low-silver-doped GrO composites against S. aureus, E. coli, and T. terra microorganisms, respectively. However, both composites showed similar inhibition capacities at 5.0 mg ml−1 per chromatographic plate against the three microorganisms. This behavior may be associated with both composites reaching the threshold limit. In general, the silver acetate amount used in the silver-doped GrO composites influenced the dispersion, crystalline phase promotion, particle size distribution, and the silver particle release capacity, which modified the electrostatic adsorption type between the composites and the bacterial cell walls.

Antiinflammatory Lupeol and Antidiabetic Compound Coexist in Ethyl Acetate and n-Hexane Extracts from Stem Bark of Anogeissus leiocarpus (African Birch Tree): The Therapeutic Advantages

Objectives: Anogeissus leiocarpus stem bark is endowed with numerous antidiabetic properties, such as its prognostic value, treatment of organic damages, dyslipidaemia and enhancement of haematopoiesis. In addition to its antioxidant activity on oxidative stress, it accelerated wound healing and has a wide range of safety value. From the purification of its compounds to the points of crystallization it became necessary to analyse the structures for an insight into its mechanisms of actions.
 Design: Ethanolic extracts were partitioned with ethyl acetate, onto column chromatography packed with silica gel (70-230 mesh) mixed with 95% n-hexane and 5% ethyl acetate; concentrated fractions were loaded onto silica gel-coated thin layer chromatographic plate. Different compounds were observed under UV-light fluorescence and sprayed with sulfuric acid. Similar fractions were pooled, purified to crystals for Nuclear Magnetic Resonance structural analysis.
 Results: Nuclear Magnetic Resonance revealed fraction A is Lupeol, a pentacyclic triterpene anti-inflammatory compound.
 Conclusion: Lupeol in the crude ethanolic extract is significant in inflammatory pain of diabetes.
 Keywords: Lupeol, Anti-inflammatory, Anogeissus leiocarpus, Purified extract, inflammatory pain, Diabetes mellitus.

Influence of selected operating conditions on starting spot width of test substance dissolved in solvent of high elution strength

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.

Leaching Behavior of Rare Earth Elements and Aluminum from Weathered Crust Elution-Deposited Rare Earth Ore with Ammonium Formate Inhibitor

In situ leaching of weathered crust elution-deposited rare earth ore usually uses ammonium sulfate as the leaching agent, which poses challenges such as low mass transfer efficiency, high consumption of the leaching agent and long leaching periods. In order to intensify the leaching process of rare earth elements and reduce the impurity of leaching accompanying rare earth, ammonium sulfate and ammonium formate were mixed as a novel compound leaching agent to treat weathered crust elution-deposited rare earth ore. The effects of ammonium formate concentration, liquid/solid ratio, leaching agent pH and leaching temperature on the leaching process of rare earth (RE) and aluminum (Al) were investigated and evaluated using the chromatographic plate theory. Results showed that ammonium formate could effectively enhance the mass transfer efficiency of rare earth and significantly inhibit the mass transfer efficiency of aluminum. Leaching agent pH has a greater impact on the mass transfer efficiency of aluminum. A higher leaching temperature could enhance the mass transfer efficiency of rare earth and aluminum by providing a driving force to overcome the resistance of diffusion. The optimum conditions for leaching rare earth and aluminum are 0.1 mol/L ammonium sulfate compounded with 0.032 mol/L ammonium formate, pH 4–8 of the leaching agent, 0.8:1 liquid:solid (mL/g) ratio and room temperature. Under this condition, the mass transfer efficiency of rare earth was improved, and the mass transfer efficiency of aluminum was significantly inhibited.

Stability Study of Selected Coxibs Used in the Treatment of Rheumatoid Diseases in Various Drug Combinations

Coxibs are a group of non-steroidal anti-inflammatory drugs (NSAIDs), selective cyclooxygenase 2 inhibitors, characterized by a much lower gastrotoxicity compared to classic NSAIDs. They are often used in conjunction with other drugs, which greatly increases the likelihood of adverse drug interactions. The presented study analyzed the degradation rate of celecoxib and cimicoxib in solutions under the influence of other medicinal substances at different temperatures. For this purpose, triple-drug mixtures were prepared, consisting of coxib and eleven different commonly used drugs (paracetamol, ketoprofen, diclofenac, acetylsalicylic acid, ibuprofen, meloxicam, tramadol, doxycycline, bisoprolol, and caffeine). Then, the mixtures were incubated at two temperatures. Within the time specified by the research plan, further aliquots of the mixtures were subjected to a chromatographic analysis. Separation was conducted on HPTLC F254 silica gel chromatographic plates as a stationary phase, using chloroform: acetone: toluene as a mobile phase, and was detected densitometrically at wavelengths of 254 nm. The percentage changes in the tested coxibs content, depending on the time and conditions of incubation, were presented. Based on the obtained data, the basic kinetic parameters of the degradation processes were determined. The celecoxib and cimicoxib showed a relatively high durability in changing environmental conditions. It was observed that the rate of decomposition of cimicoxib and celecoxib in the tested mixtures was different and depended on the temperature and presence of other components, with cimicoxib turning out to be a more stable compound.

Comparison of Miniaturized Chromatographic Columns and 96-Well Plates for Automated Antibody Purification under Economic and Sustainable Aspects

Therapeutic antibodies are an area of major interest in treating infectious diseases, autoimmune diseases, and cancer. Efficient purification strategies are required to discover and produce antibodies, representing a significant cost driver. Miniaturization and automation of the chromatographic purification process may contribute to cost reduction. In this article, miniaturized chromatographic columns and 96-well filter plates are used to purify an IgG antibody from cell cultures and are compared in terms of quality, cost, and sustainability. The validation results of the two miniaturized chromatographic antibody purification methods indicate high efficacy and are comparable except for minor differences in yield. The lowest cost per sample can be obtained with the miniaturized chromatographic columns, as annual throughput can be maximized with the miniaturized plates. By evaluating sustainability, significant reductions in laboratory waste produced during antibody purification can be shown, along with an increase in employee safety by using the automation system. Overall, the comparison of results shows that, in the development of new purification strategies, the type of implementation has a decisive influence on the outcomes in terms of recovery, cost-effectiveness, and sustainability.

Thin layer chromatography coupled with surface enhanced Raman scattering for rapid separation and on-site detection of multi-components

The separation and detection of multi-component mixtures has always been a challenging task. Traditional detection methods often suffer from complex operation, high cost, and low sensitivity. Surface enhanced Raman scattering (SERS) technique is a high sensitivity, powerful and rapid detection tool, which can realize the specific detection of single substance components, but it must solve the problem that multi-component mixtures cannot be accurately determined. Thin layer chromatography (TLC) technology, as a high-throughput separation technology, uses chromatographic plate as the stationary phase, and could select different developing phases for separation experiments. The advantages of TLC technology in short distance and rapid separation are widely used in protein, dye and biomedical fields. However, TLC technology has limitations in detection ability and difficulty in obtaining ideal signal intensity. The combination of TLC technology and SERS technology made the operation procedure simple and the sample size small, which can achieve rapid on-site separation and quantitative detection of mixtures. Due to the rapid development of TLC-SERS technology, it has been widely used in the investigation of various complex systems. This paper reviews the application of TLC-SERS technology in food science, environmental pollution and biomedicine.

Development and validation of high‐performance thin layer chromatographic method for simultaneous quantitation of novel combination perindopril erbumine and moxonidine hydrochloride

AbstractThe primary purpose of the present study was to develop and validate a high‐performance thin‐layer chromatography method for quantitatively determining an anti‐hypertensive agent, perindopril erbumine, and moxonidine hydrochloride in bulk and synthetic mixture. The densitometric procedure was performed on aluminum thin‐layer chromatography plates pre‐coated with silica gel 60F254, employing a combination of dichloromethane: toluene: methanol: ammonia (7:1:2:0.1 v/v/v/v) as the mobile phase. The thin‐layer chromatography scanner was operated in absorbance mode at a wavelength of 223 nm to evaluate densitograms. The linearity of the method was established in the range of 1000–5000 ng/band for perindopril erbumine and 40–200 ng/band for moxonidine hydrochloride; the correlation coefficient (r2) was 0.9993 and 0.9983, respectively. The values of a limit of detection (186.06 and 3.51 ng/band, respectively, for perindopril erbumine and moxonidine hydrochloride) and limit of quantification (620.23 and 11.73 ng/band, respectively, for perindopril erbumine and moxonidine hydrochloride) have demonstrated the sensitivity of the developed method. The reported process was precise in both intra‐day and inter‐day analysis; the percentage relative standard deviation of peak area was less than 2% and has an accuracy within 100 ± 2%. The developed method has the potential to quantify perindopril erbumine and moxonidine hydrochloride from its synthetic mixture without any interference from other components or in quality control laboratories.

Evaluation of phytochemicals and amino acid profiles of four vegetables grown on a glyphosate contaminated soil in Southwestern Nigeria

Abstract Green vegetables are examples of staple plants eating in Nigeria, and are assumed to be a well-off basis of phytochemicals and amino acids that are useful for the management and prevention of infections. However, in the farming of these vegetables, glyphosate-based herbicides (GBH (round up™)) are used as control against pests invasions which has cause reasons to be concern about their effects on the phyto-constituents present in these vegetables. In this study, we evaluated the phytochemicals constituents and amino acid profile of the leaves of Telfairia occidentalis Hook F, Amaranthus viridis Linn, Celosia argentea Linn and Cnidoscolus aconitifolius (Mill.) I. M. Johnst popular edible vegetables in Southwestern Nigeria. The vegetables seeds of these plants mentioned above were acquired from Institute of Agricultural Research and Training (IAR&T) Ibadan. And on a land designed and previously treated with a GBH (round up™) the seeds were planted and allowed to grow. A destructive method of leaves after maturation was achieved by out rightly plucking them out and air-drying under shade. Phytochemical assessments were done on milled plant samples to determine the presence of ten phyto-constituents. Centrifugation of powdered samples (2 g each) with acetonitrile at 1000 rotations per minute’s (rpm) was used to extract amino acids. Thereafter the extracts were individually spotted on a thin layer chromatography (TLC) plate and developed using the mobile phase consisting of methanol: acetic acid: water in ratio 7:2:1 v/v. The visualization for the presence of amino acids was completed by spraying the developed chromatographic plates with 0.5% ninhydrin in 2-propanol solution and observed in both day light and under the ultraviolet lamp and the retention factor (R f ).calculated for the different spots developed to determine the type of amino acids present. The assessment of phytochemicals from the four vegetables reveals the presence of alkaloids, tannins and steroids in all samples while anthraquinone glycosides, terpenoids and cardiac glycosides were absent and other phytochemicals varying in them. Ssaponins was found absent in Telfairia occidentalis and flavonoids in Cnidoscolus aconitifolius respectively. The observation of the TLC plates in daylight shows that the vegetables likely contained primary, secondary and proline amino acids while the calculation of the R f values of the TLC spots observed under an ultraviolet (UV) light indicated that amino acids found in the vegetables were methionine, tyrosine, leucine, isoleucine. However, phenylalanine was found only in Celosia argentea. The study evaluated phytochemicals and amino acids parameters in four leafy vegetables grown on contaminated glyphosate based herbicide soil and assessments shows that their medicinal properties were not altered with the minimal exposure to contaminant.

Novel Hyperspectral Analysis of Thin-Layer Chromatographic Plates-An Application to Fingerprinting of 70 Polish Grasses.

The advantages of hyperspectral imaging in videodensitometry are presented and discussed with the example of extracts from 70 Polish grasses. An inexpensive microscope camera was modified to cover the infrared spectrum range, and then 11 combinations of illumination (254 nm, 366 nm, white light), together with various filters (no filter, IRCut, UV, cobalt glass, IR pass), were used to register RGB HDR images of the same plate. It was revealed that the resulting 33 channels of information could be compressed into 5-6 principal components and then visualized separately as grayscale images. We also propose a new approach called principal component artificial coloring of images (PCACI). It allows easy classification of chromatographic spots by presenting three PC components as RGB channels, providing vivid spots with artificial colors and visualizing six principal components on two color images. The infrared region brings additional information to the registered data, orthogonal to the other channels and not redundant with photos in the visible region. This is the first published attempt to use a hyperspectral camera in TLC and it can be clearly concluded that such an approach deserves routine use and further attention.

High dynamic range in videodensitometry—a comparative study to classic videoscanning on Gentiana extracts

The advantages of high dynamic range (HDR) imaging in videodensitometry are presented and discussed on the example of Gentiana extract thin-layer fingerprints visualized under 254 nm. An inexpensive microscope camera, together with security surveillance lens, mounted instead of original camera on videodensitometry chamber, allows to grab HDR images with high tonal range using Python scripts and OpenCL library. HDR imaging preserves linearity in whole tonal range and does not destroy details in the brightest and darkest plate regions, so it can be seen as a good alternative to classical videodensitometry. Moreover, the tonemapping of HDR images can be used to present a plate photograph with enhanced visibility of weak spots and other details. Principal component analysis done on nine classic exposures and HDR image proves that HDR image contains the highest amount of extracted information from the thin-layer chromatographic plate.

Quality risk assessment and DoE – Practiced validated stability-indicating chromatographic method for quantification of Rivaroxaban in bulk and tablet dosage form

AbstractA systematic DoE and Analytical Quality by Design (AQbD) approach was utilized for the development and validation of a novel stability indicating high-performance thin–layer chromatographic (HPTLC) method for Rivaroxaban (RBN) estimation in bulk and marketed formulation. A D-optimal design was used to screen the effect of solvents, volume of solvents, time from spotting to development and time for development to scanning. ANOVA results and Pareto chart revealed that toluene, methanol, water and saturation time had an impact on retention time. The critical method and material attributes were further screened by Box-Behnken design (BBD) to achieve optimal chromatographic condition. A stress degradation study was carried out and structure of major alkaline degradant was elaborated. According to the design space, a control strategy was used with toluene: methanol: water (6:2:2) and the saturation time was 15 min. A retention factor (RF) of 0.59 ± 0.05 was achieved for RBN using chromatographic plate precoated with silica gel at detection wavelength 282 nm with optimized conditions. The linear calibration curve was achieved in the concentration range of 200–1,200 ng/band with r2 > 0.998 suggesting good coordination between analyte concentration and peak areas. The quadratic model was demonstrated as the best fit model and no interaction was noted between CMAs. The optimized HPTLC method was validated critically as stated in International Conference on Harmonization (ICH) Q2 (R1) guideline and implemented successfully for stress degradation study of RBN. The developed HPTLC method obtained through AQbD application was potentially able to resolve all degradants of RBN achieved through forced degradation study. The obtained results demonstrate that a scientific AQbD approach implementation in HPTLC method development and stress degradation study drastically minimizes the number of trials in experiments, ultimately time and cost of analysis could be minimized.