A stereoselective method has been developed for the chiral separation of the enantiomers of eight antiretroviral (ARV) drugs under subcritical conditions using a supercritical fluid chromatography apparatus. The ARVs: abacavir, tenofovir alafenamide, lamivudine, efavirenz, atazanavir, emtricitabine, dolutegravir and darunavir, are used to treat the human immunodeficiency virus (HIV). The antiretroviral

A rapid and sensitive UPLC-MS/MS method was developed and fully validated for the quantification of hyperoside in rat plasma after intragastric, intraperitoneal and intravenous administration. Geniposide was used as an internal standard, and simple liquid–liquid extraction by ethyl acetate was utilized for to extracting the analytes from the rat plasma samples. Chromatographic separation was carried

Retention and separation factors of enantiomers of several dipeptides were measured on chiral stationary phases with grafted macrocyclic antibiotic ristocetin A from different manufacturers, Chirobiotic R and Nautilus-R, using buffered and unbuffered methanol–water mixtures with 0 to 90% (v/v) of methanol as mobile phases. A remarkable difference in enantioselectivity toward both hydrophilic and hydrophobic

An analytical method based on UHPLC-PDA and LC–ESI–MS/MS was developed for the simultaneous and reliable determination of 22 antidepressant and anti-anxiety pharmaceutical compounds in adulterated functional foods. The method was validated in terms of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), method detection limit (MDL), method quantitation limit (MQL), precision

Thiowurtzine, a hexaazaisowurtzitane derivate, is a novel original non-opioid analgesic. In this article, an HPLC–UV method has been developed for rapid detection and quantification of API and related substances contained in thiowurtzine capsules. Six thiowurtzine impurities were separated successfully from each other by isocratic elution using a Luna 5u PFP (2) (150 mm × 4.6 mm, 5 µm) column with

Solanum sisymbriifolium also known as litchi tomato or sticky nightshade is one of the promising feedstocks for the production of nematicides as it was demonstrated to be efficient for the control of a wide range of pests including major potato pests, Globodera rostochiensis and Globodera pallida. While pesticidal effects are often attributed to a biologically active group of compounds called glycoalkaloids

Based on previously reported chiral separation of free amino-acids (AAs) using packed-column supercritical fluid chromatography (pSFC), it was desirable to investigate parameters influencing the response of evaporative light scattering detector (ELSD). The effect of several parameters, such as SFC conditions (outlet pressure, temperature and flow rate) and ELSD settings (drift tube temperature of nebulisation

The development of reliable protocols suitable for the characterisation of the physical properties of nanoparticles in suspension is becoming crucial to assess the potential biological as well as toxicological impact of nanoparticles. Amongst sizing techniques, asymmetric flow field flow fractionation (AF4) coupled to online size detectors represents one of the most robust and flexible options to quantify

A new hydrophilic interaction chromatography (HILIC) method was developed for free amino acid analysis in honey samples after pre-column derivatization of amino acids with dansyl chloride (Dns-Cl). This method consisted of the sample pretreatment with a modified QuEChERS extraction and liquid chromatographic analysis with UV detection. The derivatized amino acids were separated on a HILIC column (NH2-HILIC

Depolymerized real lignin products are very complex mixtures. Comprehensive assessment of the decomposition efficiency and characterizing of depolymerized products still remain extremely challenging. In this study, based on depolymerization solution of commercially available sodium lignosulfonate under mild conditions, an improved method was well established for characterization of real lignin depolymerized

Herein, we proposed a simple and efficient microwave-assisted preparation method for the fabrication of zirconium (IV) intercalated expanded graphite (Zr-EG). The synthetic approach could be completed in one step within 20 s, where KMnO4 was used as the oxidizing agent, H2SO4 and ZrOCl2 as the intercalating agents. The as-prepared Zr-EG exhibited thin multi-layered structure, plenty of small Zr-relevant

Detailed plots of diffusion coefficients, Dm, versus % methanol in CO2 and pressure, P, are presented. Using sub-2 µm particle columns with small ID connector tubing make for large pressure drops, ∆P, across both the system and the column. This creates low average Dm, and large gradients in Dm, slowing the chromatography. The ∆P with 75 µm ID tubing varies non-linearly with flow creating U shaped plots

The piscicide CFT Legumine is applied to freshwater systems around the world to control invasive fish species. Rotenone, a potent inhibitor of mitochondrial cellular respiration, is the active ingredient of the piscicide; however, other rotenoids of unknown persistence and toxicity account for an equivalent amount by weight. This work identified six distinct rotenoids in CFT Legumine using liquid chromatography

Cyclizine (CYZ) abuse is commonly reported, either through oral or intravenous routes, for its euphoric or hallucinatory effects. The concomitant misuse of CYZ among addicted teenagers leads to life-threatening neuromuscular disorders. Consequently, two green and validated chromatographic methods were developed for the determination of CYZ, an antiemetic drug, in its parenteral formulation in the presence

Approximate equations for the numbers of singlet peaks and total peaks in two-dimensional (2D) separations of randomly distributed component zones predict values of zero as the second-dimension peak capacity 2nc goes to zero. This is the result of deriving the equations for an unbounded 2D space. More rigorous equations are needed to assess how large 2nc must be before the error in the approximate

The study was dedicated to retention regularities and adsorption thermodynamics of enantiomers of aromatic hydroxy acids and their derivatives on chiral stationary phases (CSPs) Nautilus-E, Nautilus-R and Chirobiotic T with antibiotics eremomycin, ristomycin and teicoplanin from water–ethanol eluents under conditions of linear liquid chromatography. The enantioselective properties of the chiral adsorbents

Methamphetamine (MA) and amphetamine (AM) are central nervous system doping agents, listed in the WADA Prohibited List, which in the past years showed the highest prevalence among all stimulants. Specifically, concerning these stimulants, it is essential to distinguish between d and l-isomers of AM and MA due to their distinction in illicit or legal nonprescription use. The main separation methods

Abstract The CARISOMA™ consists of carisoprodol (CAR), paracetamol (PCM) and caffeine (CAF) used for fibromyalgia and osteoarthritis. The study discussed the comparative study of UV chemometrics (method A), ratio spectra derivative (method B) and HPLC-QbD (method C) for simultaneous estimation of the aforementioned drugs in API and marketed tablet formulation. From the listed methods, method A can

The separation of carbohydrate diastereomers by an ideal size-exclusion mechanism, i.e., in the absence of enthalpic contributions to the separation, can be considered one of the grand challenges in chromatography: Can a difference in the location of a single axial hydroxy group on a pyranose ring (e.g., the axial OH being located on carbon 2 versus on carbon 4 of the ring) sufficiently affect the

An analytical method for the accurate determination of carbamate pesticides, carbaryl, carbendazim, and carbofuran, in vegetables was established based on the isotope dilution liquid chromatography/tandem mass spectrometry (ID-LC/MS/MS) technique as a candidate reference method. For sample clean-up, a Carb/LC-NH2 solid-phase extraction (SPE) cartridge was employed to ensure an efficient recovery and

Liquid nonbeverage alcohol products including flavors/flavorings, dietary supplements, medicines, etc. can be complex mixtures of flavor chemicals, adjuvants, and solvents. Ethanol and propylene glycol (PG) are common solvents used in the manufacture of nonbeverage alcohol products and the quantification of these analytes is important for both regulatory and quality control purposes. Presented here

A new dimeric aporphine alkaloid, biscocsarmine, 2, together with lirioferine, 1, and cocsarmine, 3, were isolated from the ethanol extract of the stems of Triclisia dictyophylla Diels (Menispermaceae) using a preparative pH-zone refining CCC in a single step. The first solvent system family tested for this fractionation was hexane–ethyl acetate–methanol–water (HEMWat) at a series of solvent ratios

RP-HPLC-PDA method has been developed and validated for the quantification of Steviol glycoside: Rebaudioside A in aqueous extract of Stevia rebaudiana plant leaf. Rebaudioside A was separated on a Phenomenex Luna C18 analytical column with column temperature 40 °C using an isocratic solvent system consisting (70:30 v/v) mixture of 10 mmol/L sodium phosphate buffer and acetonitrile having pH-2.6 at

Estradiol valerate (EST) and Norethisterone acetate (NOR) are co-formulated as a hormone replacement therapy. Naturally occurring steroidal hormones like estradiol, estrone and estriol are also considered as impurities in drug substance. Chromatographic separation of these five steroidal hormones was developed by HPLC and TLC. Reversed-phase chromatography was applied using either acetonitrile–methanol

A novel approach is introduced for reliable prediction of the retention time of morphine and its derivatives, which have widespread use in medical and pharmaceutical applications. A core correlation is introduced based on the number of carbon and hydrogen atoms as well as the number of ester, noncyclic ether, and ketone functional groups from experimental data of 42 compounds. An improved correlation

New ion interaction chromatographic (IIC) system with RP column and boric acid plus tetra-n-butylammonium hydroxide (TBAOH) mobile phase was investigated. In the system: CPhenylHexyl—10 mM H3BO3/4 mM TBAOH, a large group of anions viz. F−,IO3−, Cl−, ClO2−, BrO3−, NO2−, Br−, NO3−, ClO3−, I−, HPO42−, SO42−, CrO42−, S2O32−, benzoate−, SCN−, ClO4− and phthalate2−, could be isocratically resolved. A study

As a result of the excipient materials added to the drug substance to create a formulated pharmaceutical product, the preparation of drug product samples for chromatographic or other quantitative analysis can be manually intensive and time-consuming. It is therefore important that enough focus is placed on this aspect of method development to ensure accurate and reproducible results are obtainable

In the present work, the development and application of two HPLC methods enabling the semipreparative enantioresolution of 1-(biphenyl-3-yl)-2-(1H-imidazol-1-yl)ethanol (1) and 1-[4-[(4-bromobenzyl)oxy]phenyl]-2-(1H-imidazol-1-yl)ethanol (2), two among the most potent and selective heme oxygenase-1 (HO-1) inhibitors known, are described. During the optimization step, different chiral stationary phase

In this work, the synthesis, characterization and chromatographic performance of a silica material chemically bonded with a liquid crystal based on terminal citronellol for HPLC separation were investigated. This bonded liquid crystal stationary phase denoted as LC-LCC8 resulted from the grafting of a mesogenic carboxylic acid, 3′-((3,7-dimethyloct-6-en-1-y1)oxy)-[1,1′-biphenyl]-4-carboxylic acid (LCC8)

An ultrasound-assisted deep eutectic solvent-based liquid-phase microextraction (UA-DES-LPME) was established, for the first time, for the extraction of carbamazepine (CBZ) from human plasma samples. The extract was determined by HPLC-ultraviolet detection (HPLC–UV). A deep eutectic solvent (DES) was readily synthesized by mixing choline chloride and phenol (ChCl:Ph) in the mole ratio of 1:2 in ambient

In this study, Radix Paeoniae Alba with different appearance traits and from three geographical regions was analyzed using a combination of high-performance liquid chromatography fingerprints, chemometrics, and content determination. Hierarchically clustered heatmap was developed for sample visualization. Principal component analysis was used to classify 47 Radix Paeoniae Alba samples with different

In this study, the influence of the different mobile phase compositions on the sensitivity and chromatographic performance of prohibited small peptides (< 2 kDa), their metabolites, and non-peptide substances (anamorelin, ibutamoren) were demonstrated using LC–electrospray ionization coupled with triple quadrupole tandem mass spectrometry (LC–ESI–MS/MS). In the mobile phase, widely used mobile phase

A method involving pyrolysis pretreatment followed by ion chromatography was developed to determine the residual thionyl chloride in levetiracetam. Levetiracetam was combusted at high temperature. After the pyrolysis gas was absorbed, the sulfur in thionyl chloride was converted to sulfate, which were determined by ion chromatography with conductivity detector using potassium hydroxide as the mobile

In this study, the chemical profile of Ling-Gui-Zhu-Gan Decoction (LGZGD) which was prepared by the method recorded in Synopsis of Golden Chamber was analyzed by LC–QTOF MS. A total of 89 compounds were identified, including flavonoids, pentacyclic triterpenes, glycosides, organic acids and others. Among them, nine major active components with high response value in chromatogram were selected for quantification

In this research, three novel ultra-hydrophobic, low-viscosity, non-ionic, and heavier-than-water deep eutectic solvents (DES) based on salol and terpenes are proposed. The prepared DESs were effectively used as extraction solvents in the solidification of settled organic drop (SSOD) microextraction. Despite other hydrophobic DESs, these sustainable bio-compatible extraction mediums are compatible

A novel HPLC method was developed and validated to simultaneously determine curcuminoids and dasatinib in a new dosage form. Excellent separation was achieved for a curcuminoids mixture and dasatinib with a ZORBAX Eclipse Plus Phenyl–Hexyl column (4.6 × 250 mm, 5 µm) and a mobile phase consisting of aqueous solution (0.2% acetic acid and 0.1% trifluoroacetic acid with the pH adjusted to 3.5) and acetonitrile

To explore the pharmacokinetic characteristics of the three monoterpene glycosides (paeoniflorin, albiflorin and oxypaeoniflorin) extracted from the Radix Paeoniae Rubra (RPR), we determined the plasma concentrations of these components in the cerebral ischemia–reperfusion (CIR) rats and the normal rats by a self-developed and validated ultra-performance liquid chromatography-tandem mass spectrometry

A new, sensitive, robust RP-HPLC method was developed using quality by design (QbD) approach for the determination of perampanel in pharmaceutical tablets. Screening of five independent factors; concentration and pH of the phosphate buffer, temperature, flow rate and % of the aqueous part of mobile phase; was performed by a fractional factorial design (FFD). Optimization of the significant variables

To determine deferasirox in human breast milk a novel, sensitive high-performance liquid chromatographic method with fluorescence detection has been developed. Precolumn derivatization process is applied to achieve fluorescent analyte using 4-bromomethyl-7-methoxy coumarin (BrMmC) as a reagent and dibenzo-18-crown-6-ether as catalyst. The method depends on reverse phase chromatography. C18 column has

The solubility of curcumin in the pure water subcritical and water–ethanol solution (water + (5–10) % (v/v) ethanol) subcritical is investigated for the first time. The design approach taken from this study is the response surface methodology due to the Box Behnken. The experiments were performed in the temperature range of (90–150) °C, (0–10) volumetric percent of ethanol and the flow rate of (0.2–0

Synthetic cannabinoids (SCs) are the most rapidly growing class of recreational designer drugs. The rapid growth in popularity of SC use among teens and adults is of serious in our country as all of the world. These products are saturated in various plants crumb in order to make herbal appearence. They are not for human consumption and also their chemical structures are rapidly evolving. They are known

Abstract A quality by design-based stability indicating HPLC method has been developed for hydroxychloroquine sulfate impurities. The optimized HPLC method can detect and quantify the hydroxychloroquine sulfate and related organic impurities in pharmaceutical solid oral dosage forms. Nowadays, for the quantification of impurities in drug products demands more comprehensive way of analytical method

A simple, rapid and robust protocol for the characterisation of strong cation exchange columns for the analysis of small molecular weight bases is described. A range of ten different phases were characterised, and the resultant selectivity and retention factors analysed using Principal Component Analysis. The score plots for the first and second principal components described 83% of the variability

There is a growing need for chemical analyses to be performed in the field, at the point of need. Tools and techniques often found in analytical chemistry laboratories are necessary in performing these analyses, yet have, historically, been unable to do so owing to their size, cost and complexity. Technical advances in miniaturisation and liquid chromatography are enabling the translation of these

Graphene oxide (GO)-based dispersive solid phase extraction (D-SPE) method combined with multi-step preparation has been put forward for the evaluation of trace ochratoxin A (OTA) in chicken liver. The homogenized tissue sample was initially clean-up and extracted with petroleum ether, ethyl acetate and 0.1 mol/L sodium bicarbonate solution and then adsorbed using GO originally targeting for OTA. The

A composite material featuring a zirconium-based metal–organic framework and graphene oxide (Zr-MOF@GO) was synthesized by a hydrothermal method and bonded to a stainless steel wire with an inorganic binder as a solid-phase microextraction (SPME) fiber for the derivatization-free extraction and analysis of nonsteroidal anti-inflammatory drugs (NSAIDs) coupled with gas chromatography (GC). The force

In this article, we depicted the structure of the investigated fat-and water-soluble vitamins in Fig. 2.

Previously developed three-phase retention model has been extensively used to understand the partition behaviors of solutes in micellar liquid chromatography (MLC). The model has been used to explain the linear plots of the reciprocal of the solute retention factor versus the micelle concentration in the mobile phase. Because a phase equilibrium model of micellization is assumed, the retention model

Dapagliflozin (DAP) is therapeutic agent for diabetes mellitus type II patients with insufficient glycemic control by exercise and diet. Stability-indicating LC–MS method was developed and validated on C8 column and method was able to separate DAP and three major hydrolytic degradation products. Structure elucidation of three major identified hydrolytic degradation products (DPs) and establishment

The combined implementation of quality by design principles and green analytical chemistry leads to development of green micellar HPLC method for analysis of atorvastatin calcium and amlodipine besylate in binary mixtures and in their tablet dosage forms within 8 min. A two-level fractional factorial design was implemented for screening of different method parameters affecting chromatographic responses

We developed a novel, rapid, sensitive, and stability-indicating UHPLC method for quantification of Perindopril (PER), Amlodipine (AML), and their impurities in pharmaceutical formulations. The optimum chromatographic separation was achieved in gradient elution mode using Agilent SB C18 (50 × 3.0 mm, 1.8 μm) column. A buffer containing 0.1% perchloric acid and acetonitrile was used as a mobile phase

Human–elephant conflicts continue to escalate as African elephants (Loxodonta africana) attempt to forage on cultivated crops. Chili pepper fencing is used as a deterrent but has varying success rates. These fences are constructed with crushed chili peppers, typically mixed in motor oil, placed on cloths, and strung around crop fields. This mixture is made using different formulas involving oil and

A simple, inexpensive, rapid and novel stability-indicating reversed-phase high-performance liquid chromatographic method employing Zorbax-CN column has been developed and validated for the determination of both, assay and related substances of Solifenacin Succinate (SOL) drug substance and in its drug product. Forced degradation study of SOL was performed at acid, base, oxidative, photolytic and thermal