High-performance Liquid Chromatographic Separation Research Articles

Novel Green Chromatographic Approaches for Estimation of a Triple Common Cold Pharmaceutical Combination.

Nowadays, there is a strong interest in the scientific community in developing innovative methodologies within a green analytical chemistry framework. Herein, we introduce the first chromatographic approaches for the concurrent estimation of paracetamol (PAR), carbinoxamine (CRX), and pseudoephedrine (PSE) intended to relieve COVID-19 and common cold symptoms. The first method was thin layer chromatography (TLC) densitometry, which depends on the separation of the studied medications on TLC silica gel plates using ethyl acetate: methanol: ammonia (7.0: 3.0: 0.2, by volume) as the developing system, and were scanned at 208.0nm. The data were linear in the ranges of 1-25μg/band for PAR, 1-25μg/band for PSE and 0.1-5μg/band for CRX. The second method was reversed-phase high-performance liquid chromatography separation on a Kromasil C18 column using a mixture of 0.01M phosphate buffer containing 0.1% triethylamine (pH3.5) adjusted with orthophosphoric acid and ethanol at a flow rate of 1.0 mL/min in a gradient program. The separated peaks were detected at 215.0 nm over a concentration range of 10-250μg/mL for PAR, 5-35μg/mL for PSE, and 0.5-25μg/mL for CRX. Both approaches were validated according to International Conference on Harmonization (ICH) guidelines. Finally, the impact of these methods on the environment was evaluated by many tools.

The optimised method of HPLC analysis of glutathione allows to determine the degree of oxidative stress in plant cell culture

Redox regulations and antioxidant defence play a central role in the acclimation of plants to their environment. Glutathione represents an essential component of the cellular antioxidant defence system, which keeps levels of reactive oxygen species (ROS) under control. High-performance liquid chromatography (HPLC) separation with fluorescence detection is a sensitive method that enables analysis of reduced and oxidised glutathione levels in small samples of plant tissues or plant cell culture. We aimed to optimise the method to obtain more accurate information about the total level of glutathione and the proportion of the reduced form (GSH) by choosing the most suitable reduction reagent and the conditions under which the reduction occurs. The applicability of the developed method was verified by analysing tobacco cells treated with hydrogen peroxide, which caused a decrease in the GSH/total glutathione ratio. Significant changes in the level of glutathione as well as in the GSH/total glutathione ratio were also observed during tobacco cell culture development.

Experimental designoptimisation and validation by accuracy profile of a novel method for Hg speciation analysis by HPLC-ICP-MS and application to Total Diet Studies.

This study addresses the development and validation of an analytical method for speciation analysis of mercury (inorganic/Hg2+ and methylmercury/CH3Hg+) in fishery products. The Hg species are separated by reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The effective separation of Hg2+ and CH3Hg+ was achieved in <8min using a peptide mapping RP column and a mobile phase containing 2-mercaptoethanol at 0.25% (v/v) and methanol at 1%(v/v). The optimization was carried out using an experimental design through response surface methodology (RSM) with central composite design (CCD), addressing both the HPLC separation and the sample extraction. The method validation was carried out based on the accuracy profile approach. For this purpose, six series of measurements were carried out in duplicate over a time span of 2 months. The limits of quantification (LOQ) were 2.5µg/kg (wet weight, ww) for CH3Hg+ and 1.2µg/kg (ww) for Hg2+. The intermediate reproducibility in terms of coefficient of variation (CVR) was <6%. The bias (%) obtained for the analysis of four certified reference materials (CRMs), namely TORT-3 (lobster hepatopancreas), SRM 1566-b (oyster tissue), SQID-1 (cuttlefish) and NMIJCRM7402-a (cod fish tissue) was <7%. This demonstrates the method robustness and suitability for routine speciation analysis of CH3Hg+ and Hg2+ in fishery products. The method is intended to be applied for the analysis of the panel of fishery products and fish-based foods in the framework of the (ongoing) third French Total Diet Study.

Recent progress for chiral stationary phases based on chiral porous materials in high-performance liquid chromatography and gas chromatography separation.

Chirality is a fundamental property of nature. Separation and analysis of racemates are of great importance in the fields of medicine and the production of chiral biopharmaceutical intermediates. Chiral chromatography has the characteristics of a wide separation range, fast separation speed, and high efficiency. The development and preparation of novel chiral stationary phases with good chiral recognition and separation capacity is the core and key of chiral chromatographic separation and analysis. In this work, the representative research progress of novel chiral porous crystal materials including chiral covalent organic frameworks, chiral porous organic cages, chiral metal-organic frameworks, and chiral metal-organic cages used as chiral stationary phases of capillary gas chromatography and high-performance liquid chromatography over the last 4 years is reviewed in detail. The chiral recognition and separation properties of the representative studies in this review are also introduced and discussed.

Choline chloride-L-lactic acid mixtures as solvents for extraction of Coumarin from cinnamon-containing foods

The determination of coumarin in generally available cinnamon-containing foods such as biscuits, cereals is important to ensure that the populations consuming these foods more frequently are not exposed to higher levels and are not at risk. This study describes the development of an analytical method for determination of coumarin in foods containing cinnamon. Solid-liquid phase extraction with conventional stirring-assisted and ultrasound-assisted extraction (UAE) procedures were used to prepare sample extracts for liquid chromatography analysis. The green solvent, a mixture of choline chloride:L-lactic acid (1:4, mol/mol)/water (50:50 v/v), as a deep eutectic solvent-like mixture, was selected as an extraction solvent. The extraction conditions were optimized by using the design of the experiment strategy obtaining parameters, temperature 47 °C, time 36 min, solvent volume 4 mL, sample amount 0.8 g, stirring speed 20 rpm for rotary stirring-assisted extraction procedure, and temperature 30 °C, time 5 min, solvent volume 3.5 mL, sample amount 0.8 g for UAE. High-performance liquid chromatography separation with a total analysis time of 12 min was performed with a stationary phase of octadecyl type and a gradient of mobile phase of methanol-1 % acetic acid. The methods were successfully validated to show the detection limit of 0.13 μg.mL−1, the linearity range of 0.4–50 µg.mL−1 (R2 = 0.999), recovery values more than 80 %, and the RSDs of less than 7 %. Rotary stirring-assisted extraction showed moderately higher recovery values than UAE, while lower RSD % was observed for UAE.

Occurrence, exposure estimation, and dietary risk assessment of biogenic amines in tea samples marketed in Malaysia

Biogenic amines (BAs) are one of the most studied food contaminants due to their widespread distribution in food matrices. However, the occurrence and dietary risks of BAs in tea, particularly in Malaysia, have not been comprehensively investigated. This study evaluates the occurrence of BAs in selected tea samples from Malaysia's market, and the estimation of the dietary exposure to assess the risk of their dietary intake. The targeted BAs (tyramine, histamine, tryptamine, spermine, spermidine, putrescine, and cadaverine) were extracted with 0.1 M HCl using ultrasound, followed by derivatization using dansyl chloride prior to high performance liquid chromatographic separation. The validated method was applied to analyzing BAs in various tea samples of different origins. Results showed that the occurrence of histamine (14.3–69.5 μg g−1) in fully fermented tea, semi-fermented tea, non-fermented tea, post-fermented tea, and tisanes was 8, 0, 63, 17, and 0%, respectively. Spermidine was found in all samples (except 2 tisanes) with concentrations ranging from 17.6 to 105.4 μg g−1. Tyramine was identified as the most prevalent BA (7.2–1271.7 μg g−1), with a detection frequency of 90.2%. Overall, the average total BAs content in fully fermented tea (284.2 μg g−1), semi-fermented tea (677.0 μg g−1), non-fermented tea (783.8 μg g−1), post-fermented tea (204.6 μg g−1), and tisanes (134.2 μg g−1) were below the recommended level of 1000 μg g−1. Dietary exposure was determined by estimated daily intake, whereas risk assessment was evaluated using the hazard quotient (HQ) and hazard index (HI) approaches. Based on the obtained HQ (≤0.017322) and HI (≤0.033437), the dietary exposure to BAs through the consumption of tea in Malaysia does not pose potential health risks to consumers.

Chemical profiling, anticonvulsant and anxiolytic effects of the smoke constituents isolated from Leonotis leonurus (L.) R.Br.

Ethnopharmacological relevanceThe use of medicinal plants for central nervous system (CNS)-related ailments, such as epilepsy and anxiety, is prevalent in South Africa. Plants from the Lamiaceae family are commonly used for their therapeutic benefits. Leonotis leonurus (L.) R.Br. has been reported in ethnobotanical literature to have anticonvulsant and anxiolytic effects through the inhalation of pyrolysis products obtained by combustion of the aerial parts. Aim and objectivesTo explore the chemical profiles and CNS activity of the smoke extract and isolated constituents of L. leonurus in zebrafish larvae, through anticonvulsive and anxiolytic activity assays. Materials and methodsThe smoke extract of L. leonurus was obtained through the combustion of the aerial parts of the plant using a custom-built smoke recovery apparatus. The chemical profile of the smoke constituents was determined using Ultra-Performance Liquid Chromatography coupled with Mass Spectrometry (UPLC-MS). Targeted compounds were subjected to preparative High-Performance Liquid Chromatography for separation before structure elucidation using Nuclear Magnetic Resonance (NMR). The maximum tolerated concentrations, as well as the anxiolytic activity of the smoke extract were determined in five days post fertilisation zebrafish larvae. Reverse-thigmotaxis and locomotor activity of larvae in the light/dark transition assay were used to determine anxiolytic activity. Zebrafish larvae at six days post fertilisation (dpf) were subjected to several concentrations of the smoke constituents of L. leonurus. The baseline locomotor activity of the larvae was tracked for 30 min, prior to addition of pentylenetetrazole (PTZ) to induce seizure-like behaviour in the larvae, after which the locomotor activity of the larvae was once again tracked for an additional 30 min. ResultsThe UPLC-MS profiles of the smoke extract revealed the presence of two main compounds, leoleorin A and leoleorin B, which were targeted and isolated. Upon subjection to NMR spectroscopy for structure elucidation, the compounds were confirmed to be labdane diterpenoids. Both leoleorin A and leoleorin B, and the smoke extract displayed suppression of the PTZ induced seizure-like behaviour in zebrafish larvae. Under light and dark conditions, the smoke extract and compounds displayed potential anxiolytic activity at different concentrations. ConclusionOur results suggest that the smoke constituents of L. leonurus may exert anticonvulsant and anxiolytic effects which align with the traditional indications and the mode of administration.

A Scoping Review on Carotenoid Profiling in Passiflora spp.: A Vast Avenue for Expanding the Knowledge on the Species.

The Passiflora genus is recognised for its ethnopharmacological, sensorial, and nutritional significance. Yet, the screening of its dietary and bioactive molecules has mainly targeted hydrophilic metabolites. Following the PRISMA-P protocol, this review assessed the current knowledge on carotenoid composition and analysis within Passiflora, examining 968 records from seven databases and including 17 studies focusing on carotenoid separation and identification in plant parts. Those publications originated in America and Asia. P. edulis was the most frequently examined species of a total of ten, while pulp was the most studied plant part (16 studies). Carotenoid analysis involved primarily high-performance liquid chromatography separation on C18 columns and detection using diode array detectors (64.71%). Most studies identified the provitamin A β-carotene and xanthophylls lutein and zeaxanthin, with their geometric configuration often neglected. Only one study described carotenoid esters. Besides the methodology's insufficient description, the lack of use of more accurate techniques and practices led to a high risk of bias in the carotenoid assignment in 17.65% of the articles. This review highlights the opportunity to broaden carotenoid studies to other species and parts within the diverse Passiflora genus, especially to wild, locally available fruits, which may have a strategic role in enhancing food diversity and security amidst climatic changes. Additionally, it urges the use of more accurate and efficient analytical methods based on green chemistry to better identify Passiflora carotenoids.

Comprehensive Review on Chiral Stationary Phases in Single-Column Simultaneous Chiral-Achiral HPLC Separation Methods.

This comprehensive review explores the utilization of chiral stationary phases (CSPs) in the context of single-column simultaneous chiral-achiral high-performance liquid chromatography (HPLC) separation methods. While CSPs have traditionally been pivotal for enantioselective drug analysis, contemporary CSPs often exhibit notable chemoselective properties. Consequently, there is a discernible trend towards the development of methodologies that enable simultaneous enantio- and chemoselective separations utilizing a single CSP-based chromatographic column. This review provides an exhaustive overview of reported HPLC methods in this domain, with a focus on four major CSP types: cyclodextrin-, glycopeptide antibiotic-, protein-, and polysaccharide-based CSPs. This article delves into the diverse applications of CSPs, encompassing various chromatographic modes such as normal phase (NP), reverse phase (RP), and polar organic (PO). This review critically discusses method development, emphasizing the additional chemoselective separation mechanisms of CSPs. It also explores possibilities for method optimization and development, concluding with future perspectives on this evolving field. Despite the inherent challenges in understanding the retention mechanisms involved in chemoselective separations, this review highlights promising trends and anticipates a growing number of simultaneous enantio- and chemoselective methods in pharmaceutical analyses, pharmacokinetic studies, and environmental sample determinations.

Moment Analysis Method for Measurement of Reaction Equilibrium and Rate Constants by Using High-Performance Liquid Chromatography.

The moment analysis method was developed for the determination of association equilibrium constant (KA) and association (ka) and dissociation (kd) rate constants of intermolecular interactions between solute and ligand molecules. They are accurately determined by using moment equations from elution peak profiles because they are measured by using high-performance liquid chromatography (HPLC) under preferable conditions that neither immobilization nor chemical modification (i.e., fluorescence labeling) of solute and ligand molecules is required. To demonstrate the effectiveness of the method, it was applied to the inclusion complex formation system between dibenzo-18-crown-6 (DB18C6) and alkaline earth metal cations, i.e., Mg2+, Ca2+, and Sr2+, as a concrete example. Because the diameter of the three metal cations is smaller than that of the inner cavity of DB18C6, the values of KA, ka, and kd were analytically determined by assuming the stoichiometry of 1:1 between DB18C6 and the metal cation. They reflected the influence of the difference in the size between the inner cavity of DB18C6 and the metal cations on the inclusion complex formation. It seems that the moment analysis method based on HPLC separation is effective for the multifaceted analysis of chemical reactions because some characteristics of the method are different from those of other conventional methods. It must contribute to the dissemination of an opportunity for the study of chemical reactions to many researchers because of the versatility of HPLC.

Cyclic Voltammetric Behaviour and High-Performance Liquid Chromatography Amperometric Determination of Levamisole

The electrochemical oxidation of levamisole, a glassy carbon electrode, was investigated over the pH range 2.0–10.0. Cyclic voltammetric investigations showed a single oxidation process was recorded, with a peak potential (Ep) shown to be pH-dependent in the range 5.0–8.0; between pH 2.0 and pH 5.0, and above pH 8.0, the Ep was found to be independent of pH, indicating apparent pKa values of 5.0 and 8.0. Peak currents were found to increase with increasing pH values. This voltammetric oxidation process was found to be consistent with a two-electron, two-proton oxidation to the corresponding sulfoxide. Based on these findings, the development of a of method based on the high-performance liquid chromatography separation of levamisole, with electrochemical detection being used for its determination, was explored. The chromatographic conditions required for the separation of levamisole were first investigated and optimized using UV detection. The conditions were identified as a 150 mm × 4.6 mm, 5 µm C18 column with a mobile phase consisting of 50% methanol, and 50%, 50 mM, pH 8.0 phosphate buffer. The technique of hydrodynamic voltammetry was applied to optimize the applied potential required for the determination of levamisole, identified as +2.3 V versus a stainless-steel pseudo-reference counter-electrode. Under the optimized conditions, levamisole exhibited a linear response of 1.00–20 mg/L (R2 = 0.999), with a detection limit of 0.27 mg/L. The possibility of determining levamisole in artificial urine was shown to be possible via simple dilution in the mobile phase. Mean recoveries of 99.7%, and 94.6%, with associated coefficients of variation of 8.2% and 10.2%, respectively, were obtained for 1.25 µg/mL (n = 5) and 2.50 µg/mL (n = 5).

A Multi-step High-Performance Liquid Chromatography (HPLC) Technique for the Extraction and Purification of Medical-Grade Cyclosporine A

Cyclosporine A (CsA), a potent immunosuppressive drug, is used to treat autoimmune diseases and prevent organ transplant recipients from rejecting their new organs. Maintaining CsA's uniformity and purity is essential to maintaining its therapeutic efficacy and safety. Impurities and contaminants in CsA formulations can exacerbate side effects and patient toxicity. Purification processes can improve the safety profile of the drug and reduce the likelihood of adverse effects by eliminating impurities. Using High-performance liquid chromatography (HPLC) methods, CsA has been isolated and refined from crude in recent years. However, after the procedure, the CsA purity was not at its best. To solve this issue, this work employs a multi-step HPLC method to increase purity levels to above 95%. When exploring the HPLC detection conditions of CsA, we found that the method from the Chinese pharmacopoeia: acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) was a better mobile phase solution, our further research, including the substitution of tert-butyl methyl ether with other buffer solvents, showed no significant improvement. At the same time, we established that the key factor affecting its separation was temperature. When the temperature is lower than 70 ℃, the HPLC separation effect worsens, the retention time increases, and the peak width becomes longer. Finally, the utilization of acetonitrile-water-tert-butyl methyl ether-phosphoric acid (430 : 520 : 50 : 1) as the mobile phase with a column temperature of 70 °C, petroleum ether: acetic acid Ethyl ester (70 : 30) as the mobile phase, and filling the φ 40 mm × 500 mm chromatography column using a 40~60 μm silica gel so that a 10 : 1 height-to-diameter ratio of the packed part is obtained, under normal temperature conditions, resulted in an average cyclosporine A yield of 80.1%. The corresponding average purity was 97.2%, of which the first isolation yield was 82.3%, and the purity was 98.1%.

Separation and quantification of organic‐related impurities of anti‐histamine drug hydroxyzine in pharmaceutical dosage forms using stability‐indicating high‐performance liquid chromatography, liquid chromatography‐mass spectrometry, and high‐resolution mass spectrometry techniques

AbstractA simple and robust high‐performance liquid chromatography (HPLC) method was developed for organic impurities of hydroxyzine hydrochloride in pharmaceuticals. The developed method was designed to estimate all organic impurities of hydroxyzine. The HPLC separation was achieved using C18 column (150 × 3.9 mm, 5 μm) along with a binary gradient consisting of mobile phases A (0.1%, trifluoroacetic acid in purified water) and B (0.05%, trifluoroacetic acid in acetonitrile), a flow rate of 0.7–mL/min, a column temperature of 30°C and a sample temperature of 25°C. The detection wavelength used was 230 nm for the estimation of impurity‐A, impurity‐B, and all unspecified impurities and degradation products, whereas impurity‐C was quantitated using 254 nm. The stability‐indicating property of the developed HPLC technique was assessed using stress testing conditions of hydrolysis, oxidation, thermal, photo‐light, and humidity. The validation study was performed for the limit of detection and limit of quantification, linearity, and recoveries were 0.03%, 0.05%, and 0.1132–2.9920 μg/mL (R2 &gt; 0.999), and 84.09%–109.74%, respectively. The proposed method is highly suitable for the determination of assay, organic impurities, and degradation products of the hydroxyzine. The chemical structure of degradation product 1 (hydroxyzine N‐Oxide) and degradation product 2 (O‐Acetyl hydroxyzine) were identified with the supporting data of LC‐mass spectrometry (LC‐MS) and high‐resolution MS.

Capillary electrokinetic chromatography for chiral separation of potential SARS-CoV-2 3CL protease inhibitors.

In this work, a capillary electrophoresis method was developed as a quality control tool to determine the enantiomeric purity of a series of five chiral compounds evaluated as potential severe acute respiratory syndrome coronavirus 2 3CL protease inhibitors. The first cyclodextrin tested, that is, highly sulfated-β-cyclodextrin, at 6% (m/v) in a 25mM phosphate buffer, using a capillary dynamically coated with polyethylene oxide, at an applied voltage of 15kV and a temperature of 25°C, was found to successfully separate the five derivatives. The limits of detection and quantification were calculated together with the greenness score of the method in order to evaluate the method in terms of analytical and environmental performance. In addition, it is noteworthy that simultaneously high-performance liquid chromatography separation of the enantiomers of the same compounds with two different columns, the amylose tris(3,5-dimethylphenylcarbamate)-coated and the cellulose tris(3,5-dichlorophenylcarbamate)-immobilized on silica stationary phases, was studied. Neither the former stationary phase nor the latter was able to separate all derivatives in a mobile phase consisting of n-heptane/propan-2-ol 80/20 (v/v).

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.

Characterization and Isolation of Piperamides from Piper nigrum Cultivated in Costa Rica

The piperamides profile of Piper nigrum cultivated in Costa Rica was studied using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (UPLC-ESI-QTOF-HRMS) on enriched-piperamides extracts. A total of 31 different piperamides were identified, 24 of them with a methylenedioxyphenyl moiety, including piperine and nine other compounds with the characteristic piperidine ring, as well as guineensine, retrofractamide B, and eight other piperamides with an N-isobutyl group. In addition, piperyline and two other compounds with a pyrrolidine ring, as well as piperflaviflorine B, holding a N-2-methylbutyl chain, were characterized. In turn, pellitorine and six other piperamides exhibiting a long olefinic chain instead of the methylenedioxyphenyl group were also tentatively identified. In addition, quantification was performed using UPLC coupled with a diode array detector (UPLC-DAD), with 15 piperamides being quantified, including piperine, piperyline, piperanine, and piperloguminine with values within the range of previous reports, while results obtained for guineensine (276.5–421.0 mg/100 g dry material) and pellitorine (414.4–725.0 mg/100 g dry material) were higher than those reported in the literature. Additionally, preparative and semi-preparative high-performance liquid chromatography (HPLC) separations allowed to isolate, besides piperine, four other piperamides, which were identified through HRMS, 1H and 13C nuclear magnetic resonance (NMR). These included retrofractamide B, guineensine, pellitorine, and (2E,4E,12Z)-N-isobutyl-octadeca-2,4,12-trienamide, with yields of 134.0 mg/100 g dry material, 209.7 mg/100 g dry material, 361.8 mg/100 g dry material and 467.0 mg/100 g dry material, respectively, with all these values higher than those reported in previous studies in the literature. The findings constitute the first report of such a number and diversity of compounds in P. nigrum cultivated in Costa Rica.

Simultaneously characterization of multiple constituents in Valeriana jatamansi Jones using an online supercritical fluid extraction-high-performance liquid chromatography/supercritical fluid chromatography-mass spectrometry system.

Valeriana jatamansi Jones is a commonly used traditional Chinese medicine, boasting rich effective compositions with versatile chemical structures and wide polarity, including iridoids, chlorogenic acid, and flavonoids. Previous reports indicate that conventional high-performance liquid chromatography (HPLC) analytical methods have proven inefficient performance in comprehensively characterizing components in Valeriana jatamansi. In the present study, a hybrid online analytical platform combining supercritical fluid extraction with both conventional HPLC separation (reverse phase) and supercritical fluid chromatography (normal phase) has been established and validated. This system can provide online extraction with two different chromatographic separation modes to increase separation ability and has been connected to a mass spectrometer to acquire high-resolution mass spectrometry data. Then, the online platform was applied to screening components in Valeriana jatamansi. A total of 117 compounds were identified, including five lignans, 18 organic acids, six flavonoids, and 88 iridoids. Thirty-three compounds were reported from Valeriana jatamansi for the first time. These results enrich our understanding of the components of Valeriana jatamansi and prove that the developed online platform in this study is a robust approach for accelerating working efficiency in comprehensively analyzing complicated samples.

A synergistic chemometric combination for whiteness and greenness assessed HPLC-DAD assay of aqueous extracts of ivy and thyme and potassium sorbate in a syrup formula

A stability-indicating fit-for-purpose method has been developed for co-determination of hederacoside C (HC), thymol (TL), and potassium sorbate (PS) combined in a syrup dosage form. Carvacrol (CL) was separated from thyme extract (THY) with demonstrated identity at high confidence. This method was based on a reversed-phase (RP) high performance liquid chromatographic (HPLC) separation of the cited analytes. The HPLC separation was performed on a RP Zorbax Eclipse XDB-C18 analytical column [250 × 4.6 mm, 5 µm (80 Å)] and SecurityGuard C18 guard column (4 × 3 mm, 5 µm) with gradient elution system of HPLC far UV grade acetonitrile and 20 mM aqueous potassium dihydrogen phosphate buffer adjusted to pH 2.1 as the mobile phase at a flow rate of 2.5 mL min−1 and column oven was set at 50 °C. Quantitation was achieved with the photodiode array detection (DAD) with interferent peak suppression. Target Measurement Uncertainty (TMU) was determined by misclassification rates approach employing 100,000 Monte Carlo simulations (MCS). The bias and imprecision standard deviation were combined as a total analytical error (TAE) and compared via an enhanced approach linked to product specifications, process variation, and shelf-life variability for proving a fit-for-purpose analytical procedure. The robustness of the method was checked using supersaturated design constructed from Plackett-Burman design (PB-SSD) which was statistically analysed via the very recent approach of autovalidation using self-validated ensemble modelling (SVEM). The calibration graphs for each analyte were rectilinear in the range of 42.12–560.00, 3.37–47.15 and 0.51–7.07 µg mL−1 for PS, HC, and TL, respectively. The proposed HPLC-DAD method was successfully applied for the determination of the investigated analytes in a syrup formula. Moreover, the whiteness and greenness of the procedure were assessed via the most recently cited approaches.

Tandem-Column High Performance Liquid Chromatography Separation of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Tandem-Column High Performance Liquid Chromatography Separation of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Advances in Extraction Techniques for Beer Flavor Compounds

Owing to the unique chemical properties exhibited by beer flavor compounds, different extraction methods have been utilized to extract these compounds from the sample matrix. Carbonyl compounds, which significantly contribute to flavor instability in beer, pose challenges in detection due to their low concentrations and reactivity. Consequently, the analysis of beer flavor compounds has focused on improving sensitivity and specificity through techniques that minimize sample preparation requirements and reduce interactions between factors involved in the analysis. Notably, extraction techniques such as headspace solid-phase microextraction (HS-SPME), stir bar sorptive extraction (SBSE), and gas diffusion microextraction (GDME) have been successfully applied to the analysis of carbonyl compounds in alcoholic beverages, including beer. Derivatization agents like 2,4-dinitrophenylhydrazine (DNPH) and O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) enhance the volatility and stability of analytes, facilitating their separation and detection in gas chromatography and high-performance liquid chromatography. Chromatographic separation methods, particularly gas chromatography and liquid chromatography, are extensively employed to identify and quantify aroma/flavor compounds in various foodstuffs, including beer. This review provides a comprehensive overview of extraction techniques and chromatographic methods used in the analysis of beer compounds.