HPLC Theory

Kazakevich, Yuri

doi:10.1002/9780470087954.ch2

Cited by 7 publications

(6 citation statements)

References 46 publications

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“…Figure shows how the RT can be shifted into a response surface. It is observed that increases in the polarity of the mobile phase reduce its affinity for the analyte, which is retained on the column for a longer time, as expected (Kazakevich, ). Additionally, negative interactions were identified between the FR and W , and T and W, indicating that simultaneous changes in these variables reduce RT (Table ).…”

Section: Resultssupporting

confidence: 74%

Chromatographic method for clobetasol propionate determination in hair follicles and in different skin layers

Ângelo

Cunha-Filho

Gelfuso

2016

Biomedical Chromatography

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Clobetasol propionate (CLO) is a potent steroid used for the treatment of several dermatological diseases. Recent studies suggest its additional use in alopecia topical treatment, generating a demand for novel formulations with specific delivery into hair follicles. Hence, a selective analytical method for drug quantification in follicular structures and skin layers is required. For this, a simple HPLC-UV method was developed. Quantification was performed using a RP-C column (4.6 mm × 15 cm, 5 μm), with a mixture of methanol-acetonitrile-water (50:15:35 v/v) as mobile phase, a flow rate of 1.2 mL/min, oven temperature of 30°C, injection volume of 50 μL and detection at 240 nm. The optimized conditions enabled a 12 min running with CLO elution at 10.1 min and resolution of 2.424 from skin matrix interferences. Validation was performed in accordance with International Conference on Harmonization guidelines and fulfilled the criteria of selectivity, linearity (0.5-15.0 μg/mL), robustness, precision, accuracy and limits of detection and quantification (0.02 and 0.07 μg/mL, respectively). The validated method was successfully applied for CLO quantification following in vitro skin permeation experiments and differential tape-stripping for hair follicle deposition determination, demonstrating its suitability.

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Section: Resultssupporting

confidence: 74%

Chromatographic method for clobetasol propionate determination in hair follicles and in different skin layers

Ângelo

Cunha-Filho

Gelfuso

2016

Biomedical Chromatography

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“…This is indeed the case with acetonitrile (e r 5 36.64 at 201C [31], as compared with 80.20 for water [32]), the solvent typically used in HILIC and also in this work. Lower relative static permittivity is accompanied by decreased stabilization of ions, and this will be manifested in increased values for both s s pK a and s s pK b as the acetonitrile content in an aqueous acetonitrile eluent is increased [33]. Correspond-ingly, when the acid/base equilibrium of an amine base is expressed as the dissociation of the protonated amine ([BH 1 ]#[B]1[H 1 ]; cf.…”

Section: Effect Of Ph On Retentionmentioning

confidence: 99%

“…Acids are generally more affected than bases, and linear relationships have been found at acetonitrile concentrations up to 60% v/v for most acids studied. Bases show more complex relationships and can show a minimum in the s s pK a for dissociation of its corresponding salt at intermediate acetonitrile concentrations [33]. Above 60% v/v acetonitrile, strong deviations start to take place, explained by homo-and heteroconjugation when the amount of water available for forming hydrogen bonds with the buffer compounds and solutes decreases [34].…”

Section: Effect Of Ph On Retentionmentioning

confidence: 99%

Tris(hydroxymethyl)aminomethane‐functionalized silica particles and their application for hydrophilic interaction chromatography

Bui

Verhage

Irgum

2010

J of Separation Science

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A new method is presented for synthesizing a highly hydrophilic silica-based material for use in hydrophilic interaction chromatography. Porous silica particles used as a starting substrate were modified with 3-bromopropyl trichlorosilane and grafted with glycidyl methacrylate by controlled ("living") atom transfer radical polymerization in order to introduce an oxirane-carrying reactive tentacle layer on the silica surface. The grafted material was thereafter subject to an oxirane ring opening reaction with tris(hydroxy-methyl)aminomethane in dimethylformamide to yield a polymer-bound equivalent of the well known and highly hydrophilic "TRIS" buffering substance. Chemical characterization was done by diffuse reflectance FT-IR, X-ray photoelectron spectroscopy, elemental analysis, and (1)H NMR. Porosity and surface area examination was done with Brunauer-Emmett-Teller. Chromatographic application of the material was evaluated by separations of nucleic bases, small organic acids, and common nucleotides under mixed hydrophilic interaction chromatography and weak anion exchange conditions.

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“…Strengthened signals are transmitted to the computer, where the obtained data are registered and properly processed [19]. The separation is based on competition of the molecules of the eluent and the substance being analyzed for the space on the adsorbent surface in the column [63,64].…”

Section: Chromatographic Techniques For the Analysis Of Luteolin Dmentioning

confidence: 99%

Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives

Juszczak

Zovko-Končić

2019

Biomolecules

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Luteolin is a flavonoid often found in various medicinal plants that exhibits multiple biological effects such as antioxidant, anti-inflammatory and immunomodulatory activity. Commercially available medicinal plants and their preparations containing luteolin are often used in the treatment of hypertension, inflammatory diseases, and even cancer. However, to establish the quality of such preparations, appropriate analytical methods should be used. Therefore, the present paper provides the first comprehensive review of the current analytical methods that were developed and validated for the quantitative determination of luteolin and its C- and O-derivatives including orientin, isoorientin, luteolin 7-O-glucoside and others. It provides a systematic overview of chromatographic analytical techniques including thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), liquid chromatography (LC), high performance liquid chromatography (HPLC), gas chromatography (GC) and counter-current chromatography (CCC), as well as the conditions used in the determination of luteolin and its derivatives in plant material.

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HPLC Theory

Cited by 7 publications

References 46 publications

Chromatographic method for clobetasol propionate determination in hair follicles and in different skin layers

Chromatographic method for clobetasol propionate determination in hair follicles and in different skin layers

Tris(hydroxymethyl)aminomethane‐functionalized silica particles and their application for hydrophilic interaction chromatography

Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives

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