Modelling retention in liquid chromatography of polyphenolic acids

Şanlı, Nurullah; Fonrodona, G.; Barbosa, J.; Özkan, Güleren; Beltrán, José Luís

doi:10.1016/j.aca.2005.01.006

Cited by 26 publications

(9 citation statements)

References 38 publications

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“…Gradient elution has usually been mandatory in recognition of the complexity of the phenolic profile. Binary systems comprising an aqueous component (acetic, formic, or phosphoric acid) and a less polar organic solvent such as acetonitrile or methanol are commonly used [17]. Most of the analysis methods for phenolic acids using conventional silica-based columns typically take between thirty minutes and one hour [11,12,15].…”

Section: Introductionmentioning

confidence: 99%

Analysis of phenolic acids in fruits by HPLC with monolithic columns

Biesaga¹,

Ochnik

Pyrzyńska

2007

J of Separation Science

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Reversed-phase HPLC was optimised for simultaneous determination of several derivatives of benzoic and hydroxycinnamic acids (so-called phenolic acids) in plums using a commercially available monolithic column. Mobile phase pH and concentration of organic modifier (methanol and acetonitrile) were tested in order to obtain the best resolution. Satisfactory separation was achieved in gradient mode with a mobile phase consisting of 50 mM phosphate buffer at pH 2.2 (solvent A) and acetonitrile (solvent B). The limits of detection for a UV detector ranged between 0.098 and 2.04 microg/mL for vanillic acid and p-hydroxyphenylacetic acid, respectively. The developed method was used for monitoring the content of polyphenolic acids in plums during their ripening process. The presence of these constituents was confirmed by checking their MS spectra.

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Section: Introductionmentioning

confidence: 99%

Analysis of phenolic acids in fruits by HPLC with monolithic columns

Biesaga¹,

Ochnik

Pyrzyńska

2007

J of Separation Science

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“…The coefficients described a retention behavior of this solute using Eqs. (8), (9) and (10) are listed in Table 2. The retention behavior of SSZ was accurately modeled as a function of pH and polarity of the mobile phase with the equations proposed.…”

Section: Resultsmentioning

confidence: 99%

“…(8), (9) and (10) were evaluated statistically for SSZ at different conditions. In this way, a complete description of the retention behavior of compound in the space defined by the pH of the mobile phase and variables was obtained.…”

Section: Resultsmentioning

confidence: 99%

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RPLC determination of acid dissociation constants and quantitative estimation for sulfasalazine

2015

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disease-modifying antirheumatic drug (DMARD) used in the treatment of patients with rheumatoid arthritis. Clinical studies during the last two decades have provided evidence of the drug's efficacy in the treatment of both ulcerative colitis and Crohn's disease [1].Acid dissociation constant values (pK a ) are useful physicochemical measurements describing the extent of ionization of functional groups with respect to pH. This parameter is important in pharmaceutical drug discovery and development [2]. Various experimental modalities have been used for the determination of the pK a values, comprising potentiometric titration [3], spectrophotometry [4], high performance liquid chromatography (HPLC) [5, 6] and capillary electrophoresis (CE) methodology [7]. Among these techniques, most of the drugs can be analyzed by reversed-phase liquid chromatography (RPLC) technique because of the several advantages like rapidity, specificity, accuracy, precision and ease of automation in this method.Analysis of the change in retention time of the analyte versus the change in pH of the mobile phase is given an indirect measure of the acid dissociation constant. The theory for studying the pH dependence of chromatographic retention for ionizable compounds in LC was proposed by Horvath et al. and verified by different authors for different type of compounds [8-10]. For a triprotic acid (H 3 A), Eqs. (1), (2) and (3) represent the variation of the retention factors at different pH values.(Abstract Acid dissociation constant value (pK a ) is key parameter for predicting the extent of the ionization of a drug molecule at different pH. The effect of the mobile phase composition on the acid dissociation constant values was studied by measuring the pK a values at different acetonitrile concentrations, ranging from 25 to 35 % (v/v). pK a values and limiting retention factors of SSZ were calculated chromatographically using equations derived. From calculated pK a values, the aqueous pK a values of SSZ were calculated by various approaches. Moreover, the correlation established between retention factors and the pH of the water-acetonitrile mobile phase was used to determine the optimum separation condition. Optimized condition was also validated with respect to system suitability, linearity, precision, accuracy, limit of detection and limit of quantitation, respectively. A Gemini NX C18 column (250 × 4.6 mm I.D., 5 µm particles) was used for all the determinations.

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“…The chromatographic retention of acids and bases depends on their ionization, and thus on the pH of the buffered mobile phase. In reversed-phase liquid chromatography this retention profile has been widely studied by our research group [1][2][3][4][5][6][7] and others [8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Retention-pH profiles of acids and bases in hydrophilic interaction liquid chromatography

Alvarez-Segura

Subirats

Rosés

2019

Analytica Chimica Acta

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The high proportion of acetonitrile used in many HILIC mobile phases significantly changes the acid-base properties of pH buffers and analytes foreseen from available data in water. In this paper, the recommended stability pH range for chromatographic columns is examined with various acetonitrile water mixtures, resulting in a significant broadening in the operational pH window with the content of organic solvent. Additionally, the challenge of buffer selection in HILIC is also addressed. Commonly used ammonium acetate shrinks its pH buffering range in acetonitrile-rich mobile phases due to variations in the dissociation constants of the buffer constituents (acetic acid and ammonium). Thus, other organic acids such as formic acid, TFA, and succinimide have been studied as buffers in order to fully cover the pH range of use of the column. Also the retention-pH profiles of several acids and bases have been studied in 80% and 90% acetonitrile using the proposed buffers and their behavior compared to that obtained with buffers prepared from oxalic acid, pyrrolidine, and triethylamine. The latter two show additional interactions in 80% acetonitrile that distort the expected retention-pH profiles of acid analytes, but not the ones of bases. In 90% acetonitrile the profiles are affected by significant additional solute-buffer interactions that might be caused by ion pairing, homo-and heteroassociation in this low ion solvating medium. Highlights The stability pH range of a column depends on the mobile phase composition. The aqueous buffering pH range of ammonium acetate shrinks in HILIC conditions. Proposed buffers cover the stability pH range of HILIC columns. Acid-base reversed-phase partition retention models can be applied to HILIC. Acetonitrile rich mobile phases shift pKa values of analytes and buffering species. Interactions between ionized analytes and buffers can distort expected retention profiles.

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Modelling retention in liquid chromatography of polyphenolic acids

Cited by 26 publications

References 38 publications

Analysis of phenolic acids in fruits by HPLC with monolithic columns

Analysis of phenolic acids in fruits by HPLC with monolithic columns

RPLC determination of acid dissociation constants and quantitative estimation for sulfasalazine

Retention-pH profiles of acids and bases in hydrophilic interaction liquid chromatography

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