A universal procedure of modeling chromatography separation, based on the plate model, has been developed. On each plate, the equilibrium between the analyte in the mobile and stationary phases is established. This equilibrium may be described by the concentration-dependent partition coefficient. The establishment of the equilibrium on each plate is followed by the displacement of the analyte in the

Molecularly imprinted cryogels for protein recognition have received much attention in recent years with the development of supermacroporous polymer systems. Molecularly imprinted cryogels, which offer great advantages for the selective and effective purification and separation of biomacromolecules from their sources, have become an important candidate for affinity matrix. Cryogels with their macroporous

Colistin is an old antibiotic reintroduced in response to an increased incidence of multi-resistant Gram-negative bacterial infections. It has a narrow therapeutic window, and dose optimization is required. Dose optimization requires accurate method of measurement. The goal of this manuscript is to review previously developed methods, their advantages and disadvantages, and problems to be addressed

Reactive oxygen species including free radicals are responsible for noxious changes in living organisms which can be associated with many diseases for e.g. cardiovascular, neurodegenerative, and inflammatory diseases or cancer. In the struggle against free radicals the organism is supported by antioxidants. As they are often provided by nature, they can be considered safe. 5-Caffeoylquinic acid is

Cloud point extraction (CPE) is a simple, inexpensive and green sample enrichment technique for different analytes in different matrices. In this technique surfactant solution is used at concentration above critical micelle concentration to extract the analytes from various matrices. Capillary electrophoresis (CE) and family of related techniques have emerged as powerful analytical techniques for pharmaceutical

The green glycine ionic liquid functionalized β-cyclodextrin polymer material (AAIL-β-CDCP) was synthesized and characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM). A novel method of solid phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC) for separaton/detection of pyrethroids (permethrin and fenpropathrin) was established

A new simple extraction method has been developed for determination 20 banned organochlorine (OC) pesticide residues and 16 Environmental Protection Agency (EPA) priority pollutant polycyclic aromatic hydrocarbons (PAHs) using gas chromatography equipped with a mass-spectrometric detector (GC-MS). Various extraction processes were studied, the final extraction method was applied by liquid-liquid partition

A nonlinear and non-isothermal two-dimensional lumped kinetic model (2D LKM) is solved numerically to simulate the transport of multi-component mixtures in fixed-bed liquid chromatographic columns of cylindrical geometry packed with core-shell particles. The model considers axial and radial dispersions, interfacial mass, and heat transfers, nonlinear adsorption, and rectangular pulse injections. It

A simple and reliable analytical method was established for the quantitative determination of five phosphates (orthophosphate, pyrophosphate, trimetaphosphate, tripolyphosphate, and hexametaphosphate) in dairy products by ion chromatography (IC). The samples were deproteinized with 2% trifluoroacetic acid, defatted with n-hexane, and then purified on a C18 solid phase extraction cartridge. Five phosphates

3,4-Methylenedioxymethamphetamine (MDMA) is a popular illicit drug. Given its adverse effects, the growing abuse of MDMA worldwide, and the need for forensic chemistry methods that minimize environmental issues, here we report a green approach for quantitative MDMA analysis in ecstasy tablets based on phenyl reversed-phase liquid-chromatography coupled to a diode-array detector. Water with 0.1% formic

The photodegradation of pranoprofen (PP), which is a member of the 2-arylpropionic acid family of non-steroidal anti-inflammatory drugs, in aqueous media under ultraviolet light (UV) irradiation was studied herein. Our purpose is to clarify the photostability and photochemical behavior of PP. The photodegradation of PP and the generation of its photoproducts were monitored by means of high-performance

Sixty picomoles of human serum albumin (HSA) was immobilized on a glycidylmethacrylate (GMA) capillary column previously developed by our group to study its binding with two universal cancer peptides (UCPs). Zonal HPLC experiments demonstrated that UCP2 and UCP4 have 1:1 interaction at the well-known site I of HSA with similar affinities in the micromolar range. At pH 7.4 UCP2 and UCP4 bound to HSA

A universal procedure of modeling chromatography separation, based on the plate model, has been developed. On each plate, the equilibrium between the analyte in the mobile and stationary phases is established. This equilibrium may be described by the concentration-dependent partition coefficient. The establishment of the equilibrium on each plate is followed by the displacement of the analyte in the

The quality of 12 basils (Ocimum basilicum L.) extracts was evaluated based on content of phenolics, antioxidant activity, high-performance liquid chromatography (HPLC) fingerprint combined with chemometrics. Evaluation of antioxidant activity was performed using DPPH technique and total phenolic was determined using Folin–Ciocalteau reagent. Highest antioxidant activity was obtained for O. basilicum

A high-performance liquid chromatography-electrochemical detection method was developed to determine the concentration of homocysteine and cysteine in the diabetes mellitus Sprague-Dawley male rats’ cortex and hippocampus. The cortex and hippocampus of control and diabetes model rats were collected. After pretreatment, the analysis of total homocysteine and cysteine were performed on a C8 column. Under

Veterinary drugs are widely used in animal husbandry to prevent and treat animal diseases, to promote animal growth, and to improve the conversion rate of feed. However, the use of veterinary drugs in food-producing animals may leave residues of the parent compounds, and/or their metabolites in food products resulting in harmful effects to humans. To ensure food safety, sensitive and effective analytical

A new magnetic field-assisted solid-phase extraction (MFA-SPE) procedure was developed by merging the features of magnetic solid-phase extraction and magnetic in-tube solid-phase microextraction. The MFA-SPE method was coupled with HPLC-UV and applied for the separation and determination of anti-HIV drugs in biological fluids. Magnetic Fe3O4@PANI nanocomposite with core/shell structure was synthesized

A green chromatographic method is proposed for the enantioseparation of Esmolol (Amino alcohol) in which aqueous solution of the mixed surfactants is used as the alternative of organic solvents. In this work, the diastereomeric derivatives of racemic esmolol were prepared, under microwave heating conditions, using highly reactive activated chiral esters of the (S)-levofloxacin, (S)-ketoprofen, and

Polycyclic aromatic hydrocarbons (PAHs) are one species of persistent organic pollutants (POPs) with strong carcinogenicity and teratogenicity. They can be widely found in the environment, which cause great harm to the ecological environment. In addition, they endanger human health by polluting food from the natural environment and food processing. Therefore, it is necessary to accurately detect PAHs

Colistin is an old antibiotic reintroduced in response to an increased incidence of multi-resistant Gram-negative bacterial infections. It has a narrow therapeutic window, and dose optimization is required. Dose optimization requires accurate method of measurement. The goal of this manuscript is to review previously developed methods, their advantages and disadvantages, and problems to be addressed

5-fluorouracil (5-FU) refers to a fluorinated pyrimidine analogue that has been widely used as an anticancer agent for colon, head, and neck cancers. Detection of 5-FU and its metabolites; 5-fluorouridine and 5-fluoro-2-deoxyuridine in biological samples allows optimization of pharmacotherapy and encourages fundamental investigations of this medication. The development of accurate and reliable sample

Artemether; a sesquiterpene lactone is widely used for the treatment of malaria as artemisinin-based combination therapy (ACT). The present work involves the development and validation of sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method for quantification of artemether (ART) in polymeric nanoparticles. ART was transformed to α, β-unsaturated decalones by pre-column acid

Four main glucosinolates (progoitrin, epiprogoitrin, gluconapin, and neoglucobrassicin) were isolated and identified from Isatis indigotica roots (Isatidis Radix). Among these, neoglucobrassicin was the first indole glucosinolate isolated from this herb, and its structure was elucidated by NMR, MS, and X-ray diffraction analysis. The glucosinolate components of Isatidis Radix have been profiled by

Allium paradoxum, Buxus hyrcana, Convolvulus persicus, Cyclamen coum, Eryngium caucasicum, Heracleum persicum, Pimpinella affinis, Parrotia persica, Primula heterochroma, Pyrus boissieriana, Ruscus hyrcanus, and Smilax excelsa are some medicinal and food flavoring plants found in the Hyrcanian forests in Iran. This study was designed to determine the most potent antibacterial compounds from the plants

Separation of amino acids (AAs) and their simple and inexpensive determination/identification is an interesting topic in biological and protein science, different food industries, and drug factories. Also, the presentation of the chromatographic behavior of compounds in a predictive model can be effective to estimate the structural/chemical properties of analyte and mobile phases. In this work for

In this study, lipophilicity of five newly designed molecules with antibiofilm properties was estimated for the first time. The overall goal of lipophilicity evaluation in lead generation phase is to decrease the traditionally high attrition rates for compounds entering clinical trials. Lipophilicity was assessed using RP-HPLC and in silico methods. Chromatographic analyses were performed on BDS Thermo

A new approach for the simultaneous separation and indirect ultraviolet detection of four common fluorine-containing anions using 1-hexyl-3-methylimidazolium chloride as a mobile phase additive in reversed-phase chromatography was developed. The principle of separation and detection is that fluorine-containing anions and imidazolium cations form ion-pairs with ultraviolet absorption. Under the optimal

A new and simple RP-HPLC-UV method was developed for well-separation of vildagliptin raw material and its degradation products at different conditions; it uses of ammonium acetate buffer at pH= 7.5 and methanol with Athena C18 -WP (250 mm) column. Results show that six degradants have been identified using LC–MS technique, in addition to the NMR approach in some cases. One degradant at relative retention

With environmental health and safety becoming a concern for people, supercritical fluid chromatography has been regarded as a “green chemistry” method that gradually has peaked people’s interest. The purpose of this study was to establish a method to screen and quantify the quality markers of Duhuo (DH) through an environmentally friendly ultra-performance convergence chromatography (UPC2) method.

With environmental health and safety becoming a concern for people, supercritical fluid chromatography has been regarded as a “green chemistry” method that gradually has peaked people’s interest. The purpose of this study was to establish a method to screen and quantify the quality markers of Duhuo (DH) through an environmentally friendly ultra-performance convergence chromatography (UPC2) method.

A simple extraction and sensitive simultaneous analysis method for metoprolol and its metabolite alpha-hydroxy metoprolol in latent fingerprint using liquid chromatography-mass spectrometry was developed. The extraction procedure was optimized as scrubbing using cotton swabs for 30 times followed by ultrasonic assistance in 30 °C methanol for 5 min with power of 2000 W. Drug analysis was performed

Olive oils may provide health benefits, including the prevention of coronary heart diseases, cancers, and the modification of immune and inflammatory responses. These benefits mainly originate from the phenolic compounds found in olive oil. There has been no study on the advanced characterization of Albanian olive oils from various cultivars regarding phenolic compounds. Hence, a comprehensive characterization

Thermochromic inks, materials that change color at a certain temperature, are increasingly used on papers and other materials in the areas of design, commercials, and security printing. Pseudo-estrogen bisphenol A (BPA) may be one of their main compounds present in mass fractions of up to several percent. In this work, the mass fractions of BPA in thermochromic prints on seven types of paper were determined

Objectives: The objective of this study was the investigation of age- and sex-associations in a set of blood plasma metabolites in healthy male and female subjects. Methods: A comparison study design with male and female subjects of various ages was used. Metabolic profiling was performed using electrospray ionization tandem mass spectrometry that yielded 186 metabolite concentrations for each study

Different USA-origin cannabis samples were analyzed by GC-FID to quantify all possible cannabinoids and terpenoids prior to their clustering. Chromatographic analysis confirmed the presence of seven cannabinoids and sixteen terpenoids with variable levels. Among tested cannabinoids, Δ9-Tetrahydrocannabinol Δ9-THC and cannabinol CBN were available in excess amounts (1.2–8.0 wt%) and (0.22–1.1 wt%),

A simple and rapid method employing ultra-high performance liquid chromatography tandem mass spectrometry has been developed for the direct determination of acrylic acid in tap water for the first time. The method worked on a ultra-high-performance liquid chromatography system and utilized the direct injection of 10 μL volumes. Aqueous samples were filtered with 0.22 μm membrane after diluting with

Covalent organic frameworks (COFs) show excellent property, such as high porosity and excellent structure stability and were well applied in fields such as catalysis and adsorption, but most of the COFs showed similar structure and thus similar adsorption performance. Modification of simple COFs to enhance its adsorption performance in separation technique is an important issue. In this study, quaternary

Abstract A nonlinear general rate model (GRM) of liquid chromatography is formulated to analyze the influence of temperature variations on the dynamics of multi-component mixtures in a thermally insulated liquid chromatographic reactor. The mathematical model is formed by a system of nonlinear convection–diffusion reaction partial differential equations (PDEs) coupled with nonlinear algebraic equations

A rapid and reliable method based on supercritical fluid chromatography (SFC) technology was established for the analysis of 14 ultraviolet (UV) absorbents in plastic food contact materials. The separation was optimized by employing different chromatographic conditions including stationary phases, organic modifiers, column temperatures and back pressures to achieve appropriate selectivity and resolution

A fishing platform was developed using immobilized capillary enzyme reactors in combination with liquid chromatography-mass spectrometry (LC-MS) to fish acetylcholinesterase inhibitor (AChEI) from Mahonia bealei (Fort.) Carr. (M. bealei) extract. Four potential AChEIs (columbamine, jatrorrhizine, berberine, and palmatine) were successfully screened out and identified. Their AChE inhibitory activities

A two-dimensional general rate model of non-isothermal reactive column chromatography is formulated considering homogenous and heterogeneous reaction rates, slow rates of adsorption–desorption kinetics, and enthalpies of adsorption and reaction. The model is expressed by a system of six nonlinear partial differential equations (PDEs) coupled with algebraic expressions for the adsorption and reaction

The elution behavior of four sesquiterpenoids in volatile oil of Curcumae Rhizoma on reverse-phase high-performance liquid chromatography with methyl-β-cyclodextrin as mobile phase additive was studied, including germacrone, curzerene, furanodiene, and β-elemene. Stoichiometric ratio and apparent formation constants of inclusion complex formed by methyl-β-cyclodextrin and each analyte were calculated

A rapid, precise and reproducible high-performance thin-layer chromatography-mass spectroscopy (HPTLC-MS) method was developed and validated for identification and quantification of toxic aryl azo amines from chili oils, pickles and related food matrices using Merck thin-layer chromatography (TLC) silica gel F-254 plates, as a stationary phase adsorbent by CAMAG HPTLC system. Extraction of azo food

Poria cocos is an edible medicinal mushroom with the effects of inducing diuresis, excreting dampness, invigorating the spleen and tranquilizing the mind. The triterpenoids of Poria cocos as the main active ingredients have shown health benefits of the central nervous system of the human body. Accordingly, this study aimed at further understanding the antidepressant-like effect and a potential mechanism

Abstract Aerial parts of Plectranthus amboinicus (Lour.) were collected in the Northern Mexico City for a comprehensive effect-directed profiling. Its hydrodistilled P. amboinicus essential oil (PAEO) was separated on HPTLC silica gel plates with n-hexane—ethyl acetate—ethanol, 95:3:2, followed by derivatization with the anisaldehyde – sulfuric acid reagent. The UV/Vis/FLD detection was expanded by

An important part in the research of separation of various compound classes is the study of relationship between structure and property by describing the effect of structure on compounds’ chromatographic retention. The aim of this work was to study the chromatographic retention of the firstly synthesized benzimidazoles from water-acetonitrile and water-methanol solutions on hypercrosslinked polystyrene

A multiple columns and detections liquid chromatography system, including size exclusion chromatography (SEC) and reversed phase liquid chromatography (RPLC), for the analysis of macromolecules and micromolecules in ginseng root and leaf was developed. The columns were connected by two switching valves. Macromolecules were separated on a SEC column (TSK gel SuperMultipore PW-H column, 6 mm× 150 mm

The use of electromagnetic waves to improve the efficiency of analytical separation methods has received high attention in recent years. This is done in two ways, one involving the use of a magnetic absorbents and the other one using an external magnetic field to enhance the extraction efficiency. In this review, the application of magnetic field for enhancing the selectivity and sensitivity of analytical

Computational methods increasingly provide access for Quantitative-Structure-Activity Relationship (QSAR) models to molecular descriptors that have minimal identifiable or experimentally accessible chemical/physical properties. However, molecular information inherent in chromatographic data suggests chromatography as a convenient experimental platform for legitimizing newly proposed molecular descriptors

Molecularly imprinted polymers (MIPs) of melamine (MEL) were synthesized by non-covalent approach with precipitation polymerization. In this research, MEL was used as the template molecule, acrylamide (AAm) as the functional monomer, divinylbenzene (DVB) as the cross-linker, 2,2′-azobisisobutyronitrile (AIBN) as an initiator, and the mixture of dimethyl sulfoxide (DMSO) and acetonitrile (ACN) was used

The retention behavior, lipophilicity of 16,17-secoestrone derivatives and efficiency in the separation of halogenated derivatives by HPLC with pentafluorophenyl-propyl stationary phase (F5) were studied. Methanol-water (MeOH-W) and acetonitrile-water (ACN-W) were used as mobile phases in proportions according to nomograph of iso-eluotropic binary solvent mixtures. Since mobile phase ACN-W was more

Analytical techniques with sound scientific understanding and assured regulatory flexibilities for post-approval change management are the need of the current pharma scenario. In the present study, the recent concept of analytical procedure development is utilized along with quality management concepts to address the above issue. A new chromatographic method was developed for quantifying a novel antipsychotic

The azithromycin is a semisynthetic derivative of erythromycin A, and commercially produced by a series of chemical reaction involved Beckmann rearrangement followed by reductive methylation. Several azithromycin related compounds (ARCs) have been identified as impurity in the commercial products and the processes. These ARCs probably generated from impure starting material; a mixture of different

Two precise and selective stability-indicating RP-LC methods have been developed and validated for simultaneous determination of metolazone in its binary mixture with losartan potassium (method 1) and spironolactone (method 2) in the presence of their degradation products. For method 1, the chromatographic separation was achieved on Kromasil C18 column, the mobile phase consisted of a mixture of 0

The present study focused on developing a rapid, efficient, and eco-friendly method for the analysis of perfluoroalkyl carboxylic acids (PFCAs) in aqueous matrices. The proposed method was based on esterification of PFCAs by isobutyl chloroformate followed by dispersive liquid–liquid microextraction (DLLME) of the derivatives. Quantitation of the isobutyl esters of PFCAs was carried out by gas chromatography-mass

Shankhpushpi, traded in the Indian market is having different controversial botanical sources, that is, Convolvulus pluricaulis Choisy (Convulvulaceae), Clitoria ternatea Linn. (Papilionaceae), and Evolvulus alsinoides Linn. (Convulvulaceae). Simple, accurate and precise RP-HPLC-PDA method was established for quality assessment and discrimination of Shankhpushpi samples using chromatographic profiling

Quality evaluation of herbal drugs requires the assessment of identity and possible adulterations, as well as the determination of the content of active principles or markers. For that, normally, different methods, using different chromatographic techniques are prescribed in the Pharmacopeia monographs. The goal of this work is to propose a new method for evaluation, based on “comprehensive high-performance

Carpaine, the major alkaloid present in Carica papaya leaves, have recently been shown to have antiplasmodial activity. Traditionally, water decoctions of papaya leaves (boiling in water) have been used as a malaria preventative. In this paper Carpaine from the shade-dried leaves of C. papaya have been isolated, characterized, and quantified. A rapid, sensitive, and reproducible high-performance thin-layer

Over the last years, thin layer chromatography (TLC) has become an increasingly important tool in the analysis of natural compounds, being used not only as a simple method of separation, identification, and quantitative determination of natural constituents, but also as a method for evaluating the potential applications of the separated compounds, different bioassays being compatible with TLC. This

In this context, a simple RP-HPLC method is presented for the concurrent determination of Ofloxacin (OFX), Gatifloxacin (GFN), Dexamethasone sodium phosphate (DSP), and Prednisolone acetate (PA). The method has the strengths of being green, rapid, accurate, reproducible and cost-effective. The chromatographic separation utilized sodium phosphate as buffer with pH 3.0 ± 0.1 and acetonitrile 70:30 v/v