Determination of adsorption isotherms by means of HPLC: Adsorption mechanism elucidation and separation optimization

Marchetti, Nicola; Cavazzini, Alberto; Pasti, Luisa; Dondi, Francesco

doi:10.1002/jssc.200800425

Cited by 26 publications

(14 citation statements)

References 53 publications

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“…There are many evidences for determination of adsorption isotherms and mechanism by means of HPLC . Like in nonaqueous normal phase, φ is the principal factor controlling the result of separation in the HILIC mode, besides the selection of a suitable stationary phase.…”

Section: Resultsmentioning

confidence: 99%

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Taheri

Bagheri

Moazeni-Pourasil

et al. 2017

J of Separation Science

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Hydrophilic interaction liquid chromatography on bare silica presents some benefits for analysis and purification of ionizable basic alkaloids. This mode was used to separate five major opium alkaloids: morphine, codeine, thebaine, papaverine, and noscapine. Central composite design based on response surface methodology was applied for experimental design, modeling, and optimization in a single-step gradient method. The main effects and their interactions (initial percentage of modifier, changing range of modifier in run time, pH of buffer, and its concentration) were investigated in 30 experiments. Multivariate curve resolution-alternating least squares, by resolving overlapped curves, helped in the accurate calculation of baseline resolution factors to be modeled and optimized more accurately. Then three crucial resolution factors besides elution time were modeled in quadratic and cubic equations and optimized. In addition to the four factors, five extra logarithmic, and nonlogarithmic factors extracted from the four factors to give nine factors overall were inspected on mechanism of retention. It was shown that a linear combination consist of four independence variables successfully describes morphinans retentivity in a single-step gradient method.

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Section: Resultsmentioning

confidence: 99%

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Taheri

Bagheri

Moazeni-Pourasil

et al. 2017

J of Separation Science

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“…The column dead volume, measured by using KNO 3 as a marker, was 1.93 mL. A solution of Spi(τ‐dec) 0.9% w/v in MeOH/H 2 O 60:40, buffered at pH* = 7.2 with phosphate buffer 10 –2 M, was run through the column (previously equilibrated with the solvent and thermostatted at 30°C), at 0.2 mL/min, in frontal mode , until the breakthrough step was observed and the detector response proved stable. The chiral‐selector load, calculated from the Spi(τ‐dec) breakthrough time, graphically measured, and corrected for the column dead volume, was 0.63 mmol.…”

Section: Methodsmentioning

confidence: 99%

Direct chiral resolution of underivatized amino acids on a stationary phase dynamically modified with the ion‐exchanger N^τ‐decyl‐l‐spinacine

Remelli

Pozzati

Conato

2015

J of Separation Science

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Increasing attention has been devoted in the last decades to chiral chromatography, principally to high-performance liquid chromatography techniques using a chiral stationary phase. Many chiral high-performance liquid chromatography columns are commercially available, but, unfortunately, they are most often rather expensive. A cheap alternative to the commercial chiral columns is the dynamic-coating procedure of a standard achiral stationary phase with a chiral selector containing both a chiral domain and a chain or a group able to tightly (but noncovalently) bind the achiral support. This is the case of N(τ) -decyl-l-spinacine, already successfully employed to dynamically cover a reversed-phase column to separate racemic mixtures of amino acids through the ligand-exchange mechanism. In the present work, the same chiral selector is employed to separate racemic mixtures of amino acids and oligopeptides, in the absence of metal ions: no coordination complex is formed, but only electrostatic and weak nonbonding interactions between the chiral phase and the analytes are responsible for the observed enantioselectivity. The new method is simpler than the previous one, very effective in the case of aromatic amino acids and oligopeptides and also suitable for preparative purposes.

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“…Due to different interactions between stationary phase and different sample, the molecules move to different rate, therefore separation can be done [20]. B.…”

Section: Fig2 Separation Mechanismmentioning

confidence: 99%

HPLC: Principle and Maintenance with Application

Kumar¹,

Mumtaz²,

Ahmad³

2018

IJTSRD

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High performance liquid chromatography (HPLC) is a significant qualitative and quantitative technique, usually used for the estimation of pharmaceutical and biological samples. The chromatography term is derived from the Greek words namely chroma (colour) and graphein (to write). The chromatography is very accepted technique and it is mostly used analytically. It is the most resourceful, safest, reliable and fastest chromatographic technique for the quality control of drug components. This technique involves 2 phases' stationary and mobile phases. There are different types of chromatographic techniques. The separation of constituents is based on the variation between the partition coefficients of the two phases. This article is primed with an aim to review different aspects of HPLC, such as principle, types, instrumentation and application with maintenance.

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Determination of adsorption isotherms by means of HPLC: Adsorption mechanism elucidation and separation optimization

Cited by 26 publications

References 53 publications

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Direct chiral resolution of underivatized amino acids on a stationary phase dynamically modified with the ion‐exchanger N^τ‐decyl‐l‐spinacine

HPLC: Principle and Maintenance with Application

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Determination of adsorption isotherms by means of HPLC: Adsorption mechanism elucidation and separation optimization

Cited by 26 publications

References 53 publications

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids

Direct chiral resolution of underivatized amino acids on a stationary phase dynamically modified with the ion‐exchanger Nτ‐decyl‐l‐spinacine

HPLC: Principle and Maintenance with Application

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Product

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About

Direct chiral resolution of underivatized amino acids on a stationary phase dynamically modified with the ion‐exchanger N^τ‐decyl‐l‐spinacine