Liquid Chromatography Analysis Research Articles

Magnetic Rubber@Ni-Co layered double hydroxide derived from ZIF-67 template as nanostructured sorbent; application in determination of anticancer drugs in plasma samples

In this study, a magnetic three-dimensional nano-composite based on Rubber-Fe3O4@Ni-Co Layered double hydroxide derived from ZIF-67 template was synthesized by a hydrothermal method. The proposed nano-composite was used as a sorbent for the enrichment of trace amounts of anti-cancer drugs (dasatinib and erlotinib hydrochloride) from plasma samples followed by determination using high-performance liquid chromatographic analysis (HPLC-UV). The synthesized nano-sorbent was characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating-sample magnetometer, Brunauer-Emmett-Teller surface analysis, Barrett-Joyner-Halenda pore size analysis and energy dispersive X-ray spectroscopy. Under optimal experimental conditions, factors affecting on extraction efficiency such as pH, ionic strength, extraction temperature and time, desorption solvent and time, the limit of detection (LODs) and the limit of quantification (LOQs) were obtained as 0.6, 2 µg/L for both of dasatinib and erlotinib, respectively. Also, linear range of the method were 2–500 and 2–1000 µg/L for dasatinib and erlotinib, respectively. Relative standard deviations (RSD%) for the repeatability of extraction on sorbent to sorbent were obtained as 3.59, 1.97 %, and one sorbent reusability were investigated and relative standard deviation values were obtained 5.35, 3.30 % for dasatinib and erlotinib, respectively.

Feeding Performance of Argentine Stem Weevil Is Reduced by Peramine from Perennial Ryegrass Infected with Endophyte Fungus.

One of the primary supports for extensive agriculture is pasture, which can suffer severe damage from insects including the Argentine stem weevil, Listronotus bonariensis. The main control method has been the infection of ryegrass with an endophyte fungus, forming a symbiotic association that produces alkaloids. In this study, we evaluated the impact of endophyte and peramine production on the weight of L. bonariensis across seven unnamed lines (LE161-LE167), and two Lolium perenne cultivars: Jumbo and Alto AR1. L. bonariensis adults fed on leaves from LE164, LE166, and ALTO AR1 showed weight losses of 13.3%, 17.1% and 18.2%, respectively. Similarly, the corresponding alkaloidal extract from LE164, LE166, and ALTO AR1 exhibited an antifeedant effect on L. bonariensis adults in laboratory assays, as observed through weight loss or low weight gain (-12.5%, 8.8% and 4.9%, respectively). Furthermore, one alkaloid, peramine, also elicited an antifeedant effect when incorporated into an artificial diet. Liquid chromatographic analysis of the alkaloid extract revealed that peramine was present in LE164, LE166 and ALTO AR1 in amounts ranging from 46.5-184.2 ng/g. Peramine was not detected in Jumbo and the remaining experimental lines. These data suggest that L. bonariensis were susceptible to peramine produced from endophyte infection in experimental lines LE164 and LE166, as well as ALTO AR1, affecting their feeding behavior.

An eco-friendly liquid chromatographic analysis of the triple therapy protocol of amoxicillin, metronidazole and vonoprazan for H. Pylori eradication: application to combined dosage forms and simulated gastric fluid

Helicobacter pylori has a big sway when peptic ulcers are concerned. For its eradication, different protocols have been approved. Among which, the tripartite therapy protocol which embraces vonoprazan as potassium competitive acid blocker in combination with amoxicillin and metronidazole as antibiotics. An environmentally benign HPLC method is addressed in order to simultaneously determine amoxicillin (AMX), metronidazole (MET) and vonoprazan (VPZ) in bulk powder and combined tablet mixture. Full separation of AMX, MET and VPZ is accomplished using C8 column, and a gradient mobile phase system, composed of methanol and phosphate buffer of a pH value of 5. Fine linearity in the concentration ranges 50–600 µg mL−1 amoxicillin, 50–400 µg mL−1 metronidazole and 10–100 µg mL−1 vonoprazan was denoted by the high correlation coefficient (0.9999). The method accuracy and precision are confirmed upon analyzing AMX, MET and VPZ triple therapy not only in their synthetic mixtures and combined tablet mixtures but also in their combined tablet mixtures in simulated gastric fluid. AMX, MET and VPZ triple therapy could be routinely analyzed in QC labs, in case of being co-formulated, using the presented method. Three different assessment tools were adopted revealing the benign environmental impact of presented method.

Rapid quality assessment and traceability of ginger powder from Northeast India and Indian market based on near infrared spectroscopic fingerprinting.

Ginger (Zingiber officinale Rosc.) varies widely due to varying concentrations of phytochemicals and geographical origin. Rapid non-invasive quality and traceability assessment techniques ensure a sustainable value chain. The objective of this study is the development of suitable machine learning models to estimate the concentration of 6-gingerol and check traceability based on the spectral fingerprints of dried ginger samples collected from Northeast India and the Indian market using near-infrared spectrometry. Samples from the market and Northeast India underwent High Performance Liquid Chromatographic analysis for 6-gingerol content estimation. Near infrared (NIR) Spectrometer acquired spectral data. Quality prediction utilized partial least square regression (PLSR), while fingerprint-based traceability identification employed principal component analysis and t-distributed stochastic neighbor embedding (t-SNE). Model performance was assessed using RMSE and R2 values across selective wavelengths and spectral fingerprints. The standard normal variate pretreated spectral data over the wavelength region of 1,100-1,250 nm and 1,325-1,550 nm showed the optimal calibration model with root mean square error of calibration and R2 C (coefficient of determination for calibration) values of 0.87 and 0.897 respectively. A lower value (0.24) of root mean square error of prediction and a higher value (0.973) of R2 P (coefficient of determination for prediction) indicated the effectiveness of the developed model. t-SNE performed better clustering of samples based on geographical location, which was independent of gingerol content. The developed NIR spectroscopic model for Indian ginger samples predicts the 6-gingerol content and provides geographical traceability-based identification to ensure a sustainable value chain, which can promote efficiency, cost-effectiveness, consumer confidence, sustainable sourcing, traceability, and data-driven decision-making.

Comprehensive O-Glycan Analysis by Porous Graphitized Carbon Nanoliquid Chromatography-Mass Spectrometry.

The diverse and unpredictable structures of O-GalNAc-type protein glycosylation present a challenge for its structural and functional characterization in a biological system. Porous graphitized carbon (PGC) liquid chromatography (LC) coupled to mass spectrometry (MS) has become one of the most powerful methods for the global analysis of glycans in complex biological samples, mainly due to the extensive chromatographic separation of (isomeric) glycan structures and the information delivered by collision induced fragmentation in negative mode MS for structural elucidation. However, current PGC-based methodologies fail to detect the smaller glycan species consisting of one or two monosaccharides, such as the Tn (single GalNAc) antigen, which is broadly implicated in cancer biology. This limitation is caused by the loss of small saccharides during sample preparation and LC. Here, we improved the conventional PGC nano-LC-MS/MS-based strategy for O-glycan analysis, enabling the detection of truncated O-glycan species and improving isomer separation. This was achieved by the implementation of 2.7 μm PGC particles in both the trap and analytical LC columns, which provided an enhanced binding capacity and isomer separation for O-glycans. Furthermore, a novel mixed-mode PGC-boronic acid-solid phase extraction during sample preparation was established to purify a broad range of glycans in an unbiased manner, including the previously missed mono- and disaccharides. Taken together, the optimized PGC nano-LC-MS/MS platform presents a powerful component of the toolbox for comprehensive O-glycan characterization.

Changes in chemical properties and microbial communities' composition of a forest litter-based biofertilizer produced through aerated solid-state culture under different oxygen conditions.

Fermented forest litter (FFL) is a bioproduct used as biofertilizer for several decades in Eastern Asia and Latin America. It is locally handcrafted by farmers in anaerobic conditions by fermenting forest litter added with agricultural by-products such as whey, cereal bran, and molasses. The aim of this study was to characterize the FFL process and product through gas and liquid chromatography analyses. It also provides some highlights on the influence of O2 on this solid-state culture. Under anoxic condition, a maximum CO2 production rate (CDPR) of 0.41mL/h∙g dry matter (dm) was reached after 8days. The main volatile organic compounds (VOCs) were ethanol and ethyl acetate, with a production rate profile similar to CDPR. After 21days of culture, no residual sucrose nor lactose was detected. Lactic and acetic acids reached 58.8mg/g dm and 10.2mg/g dm, respectively, ensuring the acidification of the matrix to a final pH of 4.72. A metabarcoding analysis revealed that heterolactic acid bacteria (Lentilactobacillus, Leuconostoc), homolactic acid bacteria (Lactococcus), and yeasts (Saccharomyces, Clavispora) were predominant. Predicted genes in the microbiome confirmed the potential link between detected bacteria and acids and VOCs produced. When O2 was fed to the cultures, final pH reached values up to 8.5. No significant amounts of lactic nor acetic acid were found. In addition, a strong shift in microbial communities was observed, with a predominance of Proteobacteria and molds, among which are potential pathogens like Fusarium species. This suggests that particular care must be brought to maintain anoxic conditions throughout the process.

Antifungal Activity of Neem Leaf Extract With Eucalyptus citriodora Oil and Cymbopogon martini Oil Against Tinea Capitis: An In-Vitro Evaluation.

Introduction Tinea capitis, often known as ringworm of the scalp, is a fungal infection that affects the scalp, eyelashes, and eyebrows. It is generally caused by dermatophytes from the genera Trichophyton and Microsporum. Trichophyton tonsurans and Microsporum canis are the main etiological agents responsible for most of the cases of tinea capitis globally. Tinea capitis commonly manifests as itchy, scaly patches of hair loss. Tinea capitis is the prevailing dermatophyte illness among children globally. Methods An in-vitroevaluation study was conducted to assess the antifungal properties of ethanolic extracts of neem leaves and the oils of Eucalyptus citriodora and Cymbopogon martini, both individually and in combination. The agar-well diffusion method and the M38-A2 microbroth dilution method were employed to evaluate the antifungal efficacy against pathogenic dermatophyte strains, namely Microsporum canis and Trichophyton tonsurans. The fully mature green leaves were treated with ethanol to make the neem leaf extract. Additionally, high-performance liquid chromatographic analysis was carried out to determine the contents of the terpenoids. Fluconazole, an antifungal drug, is used as a standard. Results The findings demonstrated an overall inhibition of the growth of dermatophytes at a minimal inhibitory concentration of 187.5 and 375 μg/ml for neem leaf extractand 0.625 to 2.5 μl/ml for selected herbal oils,whereas it was0.25μg/mland 0.50 μg/ml forpositive controlagainstMicrosporum canisandTrichophyton tonsurans,respectively. Conclusion The phytochemical investigation of theethanolic extracts in neem leaves revealed the presence of terpenoids, which are known for their significant biological activity. The study's findings demonstrated the therapeutic capabilities of neem leaf extract in combination with the oils of Eucalyptus citriodora and Cymbopogon martini for managing the tinea capitis infection. A broader and improved antifungal spectrum was seen when neem leaf extract and oils were combined. Therefore, it can be developed into a suitable formulation for the management of tinea capitis.

Comparison of reversed-phase, hydrophilic interaction, and porous graphitic carbon chromatography columns for an untargeted toxicometabolomics study in pooled human liver microsomes, rat urine, and rat plasma

IntroductionUntargeted metabolomics studies are expected to cover a wide range of compound classes with high chemical diversity and complexity. Thus, optimizing (pre-)analytical parameters such as the analytical liquid chromatography (LC) column is crucial and the selection of the column depends primarily on the study purpose.ObjectivesThe current investigation aimed to compare six different analytical columns. First, by comparing the chromatographic resolution of selected compounds. Second, on the outcome of an untargeted toxicometabolomics study using pooled human liver microsomes (pHLM), rat plasma, and rat urine as matrices.MethodsSeparation and analysis were performed using three different reversed-phase (Phenyl-Hexyl, BEH C18, and Gold C18), two hydrophilic interaction chromatography (HILIC) (ammonium-sulfonic acid and sulfobetaine), and one porous graphitic carbon (PGC) columns coupled to high-resolution mass spectrometry (HRMS). Their impact was evaluated based on the column performance and the size of feature count, amongst others.ResultsAll three reversed-phase columns showed a similar performance, whereas the PGC column was superior to both HILIC columns at least for polar compounds. Comparing the size of feature count across all datasets, most features were detected using the Phenyl-Hexyl or sulfobetaine column. Considering the matrices, most significant features were detected in urine and pHLM after using the sulfobetaine and in plasma after using the ammonium-sulfonic acid column.ConclusionThe results underline that the outcome of this untargeted toxicometabolomic study LC-HRMS metabolomic study was highly influenced by the analytical column, with the Phenyl-Hexyl or sulfobetaine column being the most suitable. However, column selection may also depend on the investigated compounds as well as on the investigated matrix.Graphical abstract

Sustainable control of Microcystis aeruginosa, a harmful cyanobacterium, using Selaginella tamariscina extracts

Eco-friendly reagents derived from plants represent a promising strategy to mitigate the occurrence of toxic cyanobacterial blooms. The use of an amentoflavone-containing Selaginella tamariscina extract (STE) markedly decreased the number of Microcystis aeruginosa cells, thus demonstrating significant anti-cyanobacterial activity. In particular, the Microcystis-killing fraction obtained from pulverized S. tamariscina using hot-water-based extraction at temperatures of 40 °C induced cell disruption in both axenic and xenic M. aeruginosa. Liquid chromatographic analysis was also conducted to measure the concentration of amentoflavone in the STE, thus supporting the potential M. aeruginosa-specific killing effects of STE. Bacterial community analysis revealed that STE treatment led to a reduction in the relative abundance of Microcystis species while also increasing the 16S rRNA gene copy number in both xenic M. aeruginosa NIBR18 and cyanobacterial bloom samples isolated from a freshwater environment. Subsequent testing on bacteria, cyanobacteria, and algae isolated from freshwater revealed that STE was not toxic for other taxa. Furthermore, ecotoxicology assessment involving Aliivibrio fischeri, Daphnia magna, and Danio rerio found that high STE doses immobilized D. magna but did not impact the other organisms, while there was no change in the water quality. Overall, due to its effective Microcystis-killing capability and low ecotoxicity, aqueous STE represents a promising practical alternative for the management of Microcystis blooms.

Free Isoflavone (Daidzein and Genistein) Content in Soybeans, Soybean Meal and Dried Soy Hypocotyl Sprout using High Performance Liquid Chromatography (HPLC)

Background: Phytoestrogens are natural plant glucosides found primarily in legumes and grains. Phytoestrogens can interact with oestrogen receptors in the body either by mimicking or blocking the effects of oestrogen. Isoflavones are a major subclass of phytoestrogens and often comprise a substantial part of livestock feeds. This study was focused on the detection and quantification of free isoflavones especially genistein and daidzein in soy-based ingredients (soybeans, soybean meal and dried soy hypocotyl sprout) which are incorporated in the animal feed formulations. Methods and Results: The simultaneous determination of daidzein and genistein in soybeans, soybean meal and dried soy hypocotyl sprout was carried out using the analytical technique high performance liquid chromatography (HPLC). The limits of detection and quantitation were 4.81 and 14.59 µg/100 g for daidzein and 3.06 and 9.58 µg/100 g for genistein respectively. The precision of the procedure was 2.73 per cent for daidzein and 2.88 per cent for genistein. The average daidzein and genistein concentration levels were (239.16 ± 0.21 and 238.68 ± 0.27 µg/100g) for soybeans, (397.24 ± 0.64 µg/100g and 443.85 ± 0.62) for soybean meal, (551.03 ± 0.54 and 742.59 ± 0.76 µg/100g) for dried soy hypocotyl sprout. The mean recovery percentages for daidzein and genistein were 92.8 per cent and 93.66 per cent respectively. The findings indicated that all the soy-derived components examined contained isoflavones and dried soy hypocotyl sprouts possessed higher concentrations of both daidzein and genistein.

Most Probable Rate of Horizontal Spread of Phenanthrene in a Sandy Loam Soil Under Natural Environment

The rate of horizontal spread of phenanthrene applied in a plot of land of sandy loam texture is determined in a field experiment of four months duration under natural environment. Efforts were made to study the effect of different physico-chemical parameters of the soil sample on the horizontal spread of phenanthrene. The concentration of the hydrocarbon at different points of time was determined by high-performance liquid chromatographic analysis of soxhlet extract of soil samples drawn from different distances from the point of application of the hydrocarbon. Simultaneously, internal samples were also analysed in order to detect the efficiency of the process of extraction and the extent of degradation during the study period. The ambient temperature of the place of the experiment was in the range of 23.6 to 35.5°C, which is suitable for microbial activities. From the internal experiment, it was found that there was a 36% loss of phenanthrene which indicates degradation during these four months of the experiment. It has been found that most of the Phenanthrene molecules move a distance of 15 cm from the point of application in the first 60 days. As such the most probable rate of horizontal spread became 2.89 × 10-8 m s-1.

Characterization of Bixin by UV-Visible Spectroscopy and HPLC, and Its Application as Latent Fingermark Developer

Fingerprints are essential for human identification and are valuable tools in criminal investigations. The pursuit of new materials for digital printing is expanding, with increasing interest in natural compounds such as bixin, sourced from annatto seeds. Despite its traditional use as a natural dye with medicinal properties, the potential of bixin in papilloscopy remains largely untapped. In this study, we meticulously extracted bixin from annatto seeds and meticulously developed composites incorporating zinc carbonate (bixin/ZnCO3) and kaolinite (bixin/kaolinite). UV-visible spectroscopy was used for characterization, and the extracted bixin showed absorption peaks at 429, 453, and 481 nm, which were very similar to standard peaks at 429, 457, and 487 nm. The two samples also had the same retention times (7.07 min) according to further liquid chromatography analysis. Sweat pores were easier to detect thanks to the effectiveness of the bixin/ZnCO3 and bixin/kaolinite composites in creating high contrast sebaceous and natural latent fingerprints. These results highlight the composites’ potential as novel and fascinating instruments for papilloscopy applications, which might also improve forensic investigations.

Unravelling the reason for different binding behaviors exhibited by antibody aggregates towards preparative and analytical Protein A columns

We previously showed that the root cause of low Protein A step yield observed for certain antibodies/Fc-fusions is the presence of non-binding aggregates in cell culture harvest. A pre-assumption for the above conclusion is that the aggregates, while do not bind to the preparative Protein A column, can bind to the analytical Protein A-high performance liquid chromatography (HPLC) column used for titer measurement. In the current work, using materials from a previous case with the low yield issue, we confirmed that non-binding aggregates in preparative Protein A flow-through can indeed bind to the analytical Protein A column. In addition, we showed that this discrepancy is mainly due to the different loading densities applied under these two circumstances. We also demonstrated that aggregate bound to the analytical Protein A column slightly stronger than the monomer, as it exhibited a longer retention time. In summary, the current study not only confirmed that non-binding aggregates detected in the preparative Protein A flow-through bind to the Protein A-HPLC column and contribute to the measured titer of culture harvest but also unravelled the reason for different binding behaviors exhibited by antibody aggregates towards preparative and analytical Protein A columns.

Trace Determination of Phenanthrene and Fluorene in Beverages Using D-μ-SPE and Liquid Chromatography Analysis

Dispersive micro solid phase extraction (D-μ-SPE) method using Graphene Oxide (GO) for the extraction and pre-concentration of selected polycyclic aromatic hydrocarbons (PAHs) from beverage samples prior to high-performance liquid chromatography - diode array detector (HPLC - DAD) is reported. Selected PAHs Fluorene (FLU) and Phenanthrene (PHE) were used as targeted analytes. An experimental design using Response Surface Methodology (RSM) and Box–Box–Behnken design (BBD) was performed to evaluate the interactive effects of three significant parameters: mass of sorbent, sample volume and extraction time. Under the optimum conditions, the method revealed good linearity (R2 = 0.9995 – 0.9998) over a concentration range of 0.5 – 5.0 mg L-1. The limit of detection (LOD) was in the range of 0.03 – 0.24 mg L-1 with satisfactory relative recoveries (81 – 99 %) and good relative standard deviation (RSD) of ≤ 3.80 % (n = 3). The method was successfully applied to tea, coffee, and milk samples and proved to be a simple, rapid, and reliable method with good extraction efficiencies for the detection of PAHs in beverage samples.

Citrate silver nanoparticles impregnated cellulose as a photocatalytic filter in the degradation of organic dye in the aqueous media

Photocatalysis is a clean and efficient process pursued under light irradiation with a suitable photocatalyst to degrade a contaminant. We report citrate functionalization of silver nanoparticles (SNPs) for effective immobilization on cellulosic fabric. The porous cellulosic matrix could be explored as microfiltration membranes for the photocatalytic degradation of organic dyes in the aqueous media. Where valid, the citrate functionalized SNPs and the treated cellulose fabrics were considered for optical, structural, surface chemical, thermal, textile, flowability, photocatalytic, and antibacterial attributes. The SNPs expressed the bandgap energy of 2.56 and 2.43 eV and Urbach energy of 3.38 and 5.21 eV before and after functionalization with the citrate moieties, respectively. The liquid chromatographic and FTIR analyses indicated that the crystal violet (CV) organic dye has been successfully photodegraded to environmentally safer and nontoxic species on passing the contaminated water through the SNPs-treated cellulosic filter. The spectroscopic data also supported the said outcomes. The results demonstrated that the citrate-SNPs-treated cellulose could be efficiently employed as antibacterial photocatalytic membranes for degrading organic dyes in the aqueous media for multiple cycles.

Determination of ω-end functionalities in tailored poly(2-alkyl-2-oxazoline)s by liquid chromatography and mass spectrometry.

The in-depth analytical characterization of polymers, in particular regarding intended biomedical applications, is becoming increasingly important to elucidate their structure-property relationships. Specifically, end group analysis of e.g. polymers featuring a 'stealth effect' towards the immune system is of particular importance because of their use in coupling reactions to bioactive compounds. Herein, we established a liquid chromatography (LC) protocol to analyse bicyclo[6.1.0]nonyne-functionalized poly(2-alkyl-2-oxazoline)s (POx)s as promising functional polymers that can be applied in strain-promoted click reactions. This work involved the synthesis of poly(2-methyl-2-oxazoline) (PMeOx) and poly(2-ethyl-2-oxazoline) (PEtOx) by living cationic ring-opening polymerization (CROP) with different molar masses ranging from 2 up to 17.5 kDa and, to our knowledge, the first liquid chromatographic analysis of PMeOx. The developed analytical protocol enables the quantitative determination of post-polymerization reaction sequences with respect to the conversion of the ω-end groups. All synthesized polymers were straightforwardly analysed on a C18-derivatized silica monolithic column under reversed-phase chromatographic conditions with a binary mobile phase gradient comprising a mixture of acetonitrile and water. Subsequent mass spectrometry of collected elution fractions enabled the confirmation of the desired ω-end group functionalities and the identification of synthetic by-products.

Effect of ultrasonic modification on the binding ability of pectin to anthocyanin.

Pectin was considered as a potential candidate to improve the thermal stability of anthocyanins, and the binding ability of pectin to anthocyanins was influenced by its structure. In this study, sunflower pectins, modified by ultrasound (40 kHz) for different periods of time, were prepared and used to bind with anthocyanins, extracted from purple sweet potato. Characterization and thermal stability of pectin-anthocyanin complexes were investigated. The ultrasonic modification of pectin resulted in many changes in pectin chemical structure, including degradation of neutral sugar side chains, breakage of methoxyl groups, and increased molecular flexibility. Extension of ultrasonic modification time led to greater changes in pectin chemical structure. Analysis of the binding ability, as determined by Fourier transform infrared spectroscopy and molecular dynamics simulations, revealed that the interaction between pectin and anthocyanins was driven by hydrogen bonding, electrostatic interaction, and hydrophobic interaction. Pectins with different ultrasonic modification times bound with anthocyanins to different extents, mainly resulting from an increase in the number of hydrogen bonds. According to high-performance liquid chromatographic analysis, during heating at 90 °C the stronger the binding ability of pectin and anthocyanin complex, the better was its thermal stability. Ultrasonic modification of pectin could effectively enhance its binding ability to anthocyanin. © 2023 Society of Chemical Industry.

Combining Liquid Chromatography and Cryogenic IR Spectroscopy in Real Time for the Analysis of Oligosaccharides.

While the combination of liquid chromatography (LC) and mass spectrometry (MS) serves as a robust approach for oligosaccharide analysis, it has difficulty distinguishing the smallest differences between isomers. The integration of infrared (IR) spectroscopy within a mass spectrometer as an additional analytical dimension can effectively address this limitation by providing a molecular fingerprint that is unique to each isomer. However, the direct interfacing of LC-MS with IR spectroscopy presents a technical challenge arising from the mismatch in the operational time scale of each method. In previous studies, this temporal incompatibility was mitigated by employing strategies designed to slow down or broaden the LC elution peaks of interest, but this workaround is applicable only for a few species at a time, necessitating multiple LC runs for comprehensive analysis. In the current work, we directly couple LC with cryogenic IR spectroscopy by acquiring a spectrum in as little as 10 s. This allows us to generate an orthogonal data dimension for molecular identification in the same amount of time that it normally takes for LC analysis. We successfully demonstrate this approach on a commercially available human milk oligosaccharide product, acquiring spectral information on the eluting peaks in real time and using it to identify both the specified constituents and nonspecified product impurities.

Hydroethanolic extract of Piliostigma thonningii leaves extenuates the severity of diarrhoea in female Wistar rats.

Nigeria ranks second in the global prevalence of diarrhoea with most cases concentrated in the Northern-region of the country. This research explored the antidiarrhoeal efficacy of the hydroethanolic extract of Piliostigma thonningii leaves (HEPTL), locally used to manage diarrhoeal conditions in Kebbi State, Nigeria. P.thonningii leaves were screened for their secondary metabolites and mineral constituents. Using 3 standard-diarrhoea models, female Wistar rats completely-randomised into six-groups of six animals each were utilised for probing the antidiarrhoeal activity of HEPTL. Animals in groups I and II served as the negative and positive controls, whereas the rats in groups III, IV and V respectively received 50, 100, and 200 mg/kg body weight-(bw) of HEPTL. Six secondary metabolites and eight minerals were found in the extract, with flavonoids and calcium being the most abundant while steroids and zinc were the least prevalent, respectively. High performance liquid chromatographic analysis revealed the presence of 19 bioactive substances. Furthermore, there was a significant (p<0.05) and dose-related reduction in diarrhoea onset, water content, and wet faeces count. Similarly, the amount of intestinal fluid and average distance traversed by the charcoal-meal were decreased dose-dependently by the HEPTL with a commensurate rise in the suppression of intestinal fluid accrual andperistalsis. Acetylcholinesterase, Na+/K+-ATPase, reduced glutathione, intestinal-alkaline phosphatase and protein levels increased significantly (p<0.05) whereas superoxide-dismutase, catalase, intestinal-nitric oxide and malondialdehyde levels all fell significantly (p<0.05). However, the level of intestinal glucose was not significantly altered. Overall, the HEPTL exhibited a profound effect in the alleviation of the severity of diarrhoea, notably at 200 mg/kg bw.

A facile creation of hydrophilic-lipophilic-balanced covalent organic frameworks with mixed-mode retention mechanisms for multiple applications in liquid chromatography

Currently, high-performance liquid chromatographic separation materials that can provide multiple retention mechanisms are highly favored. Covalent organic frameworks (COFs) have undoubtedly demonstrated promising application prospects in chromatographic separation on account of excellent stability and porosity. Nevertheless, the utilization of COFs as liquid chromatographic fillers is still in the early stages of development. Especially, developing powerful COF@SiO2 with versatile separation capabilities still poses certain difficulties. Herein, a hydrophilic-lipophilic-balanced imine-linked COF was synthesized and in-situ growth on the amino-modified silica microsphere to obtain a multifunctional TAPT-TP-COF@SiO2 composite material. The synergistic effect of multiple functional groups including hydroxyl, amino, aldehyde, triazine and aromatic ring in the TAPT-TP-COF provided multiple retention mechanisms. The selection of 2,4,6-triformylphloroglucinol (TP) as the aldehyde counterpart improved the hydrophilic effect of the developed COF-based separation material, which enabled the effective separation of hydrophilic analytes (nucleosides, sulfonamides and vitamins). The novel TAPT-TP-COF@SiO2 column displayed typical reverse-phase and hydrophilic interaction chromatographic retention behavior. The successful applications demonstrated that TAPT-TP-COF@SiO2 had enormous potential for efficient liquid chromatographic analysis.