Generic placeholder image

Current Chromatography


ISSN (Print): 2213-2406
ISSN (Online): 2213-2414

Research Article

Sulfated Polyborate, a Novel Buffer for Low pH Mobile Phase on a Nonend Capped Stationary Phase in Reverse Phase Liquid Chromatography

Author(s): Purushottam Sutar, Pravin Khedkar and Ganesh Chaturbhuj*

Volume 8, Issue 1, 2021

Published on: 13 September, 2021

Article ID: e130921196421 Pages: 11

DOI: 10.2174/2213240608666210913110849

Price: $65


Background: Sulfated Polyborate, a novel inorganic material primarily designed as a catalyst, has shown properties such as high solubility in organic solvents, low U.V. cut-off, and pKa ≈2.0, which suggests its potential as a mobile phase buffer for reverse-phase liquid chromatography.

Objective: This study aims to substantiate the role of Sulfated Polyborate as mobile phase buffer for reverse-phase liquid chromatographic analysis of basic drugs with high pKa values viz. Bisoprolol fumarate, Timolol maleate, Verapamil hydrochloride, and Carvedilol.

Methods: Solubilities, U.V. cut-offs, and pKa of Sulfated Polyborate were first experimentally confirmed. The behaviour of Sulfated Polyborate as mobile phase buffer at pH 3.0 was ascertained by varying the buffer concentration, flow rates, and percent organic modifier for elution of the four basic drugs on a non-end capped octyl silyl (C8) column. Similarly, the study was performed with KH2PO4 as a reference buffer. The column performance and conductometric measurements ascertained the impact of Sulfated Polyborate on the stationary phase.

Results: Sulfated Polyborate and KH2PO4 buffers showed correlation coefficients of 0.99 and 1.00 for analyte retention factors for variation of buffer concentration and organic modifier composition, respectively. Peak symmetries and the number of theoretical plates were improved from > 2.0 to < 2.0 and ≈1000 to ≈3000, respectively, for variation in buffer concentrations. Similar Van Deemter plots indicated equivalency of Sulfated Polyborate and KH2PO4 buffers. The column performance and conductometric measurements depicted no adsorption on the stationary phase.

Conclusion: The present study demonstrates Sulfated Polyborate as a novel buffer for analytes with higher pKa on reverse-phase liquid chromatography.

Keywords: Sulfated polyborate, potassium dihydrogen phosphate, basic drugs, buffer, non-end capped, inorganic material.

Graphical Abstract
Snyder, L.R.; Kirkland, J.J.; Glajch, J.L. Practical HPLC method development.Wiley: New York,, 1997.
Dolan, J.W.; Snyder, L.R.; Djordjevic, N.M.; Hill, D.W.; Waeghe, T.J. Reversed-phase liquid chromatographic separation of complex samples by optimizing temperature and gradient time I. Peak capacity limitations. J. Chromatogr. A, 1999, 857(1-2), 1-20.
[] [PMID: 10536823]
Pesek, J.J.; Matyska, M.T.; Boysen, R.I.; Yang, Y.; Hearn, M.T.W. Aqueous normal-phase chromatography using silica-hydride-based stationary phases. Trends Analyt. Chem., 2013, 42, 64-73.
Abbott, S.R. Practical aspects of normal-phase chromatography. J. Chromatogr. Sci., 1980, 18(10), 540-550.
[] [PMID: 6256401]
Jungbauer, A.; Hahn, R. Ion-exchange chromatography. Methods in enzymology, guide to protein purification 2nd ; Burgess, R.R.; Deutscher, M.P., Eds.; Academic Press: San Diego, 2009, 463, pp. 349-371.
Mori, S.; Barth, H.G. Size exclusion chromatography.Springer:. Verlag: Berlin Heidelberg, 1999.
Mallik, R.; Hage, D.S. Affinity monolith chromatography. J. Sep. Sci., 2006, 29(12), 1686-1704.
[] [PMID: 16970180]
Beesley, T.E.; Scott, R.P.W. Chiral chromatography.Wiley: New York,. , 1998.
McCalley, D.V. Is hydrophilic interaction chromatography with silica columns a viable alternative to reversed-phase liquid chromatography for the analysis of ionisable compounds? J. Chromatogr. A, 2007, 1171(1-2), 46-55.
[] [PMID: 17931636]
Hanai, T. Definition of HILIC system and quantitative analysis of retention mechanisms. Curr. Chromatogr., 2018, 5, 43-52.
Ali, I.A.; Al-Othman, Z.; Al-Warthan, A.Y.; Aboul-Enein, H. Recent trends in chiral separations by nano liquid chromatography and nano capillary electrophoresis. Curr. Chromatogr., 2014, 1, 81-89.
Aboul-Enein, H.Y.; Ali, I. Studies on the effect of alcohols on the chiral discrimination mechanisms of amylose stationary phase on the enantioseparation of nebivolol by HPLC. J. Biochem. Biophys. Methods, 2001, 48(2), 175-188.
[] [PMID: 11356487]
Aboul-Enein, H.Y.; Ali, I. Optimization strategies for HPLC enantioseparation of racemic drugs using polysaccharides and macrocyclic glycopeptide antibiotic chiral stationary phases. Farmaco, 2002, 57(7), 513-529.
[] [PMID: 12164206]
Aboul-Enein, H.Y.; Ali, I. HPLC enantiomeric resolution of nebivolol on normal and reversed amylose based chiral phases. Pharmazie, 2001, 56(3), 214-216.
[PMID: 11265585]
Al-Othman, Z.A.; Al-Warthan, A.; Ali, I. Advances in enantiomeric resolution on monolithic chiral stationary phases in liquid chromatography and electrochromatography. J. Sep. Sci., 2014, 37(9-10), 1033-1057.
[] [PMID: 24634395]
Ali, I.; Al-Othman, Z.A.; Al-Warthan, A.; Asnin, L.; Chudinov, A. Advances in chiral separations of small peptides by capillary electrophoresis and chromatography. J. Sep. Sci., 2014, 37(18), 2447-2466.
[] [PMID: 25044566]
Aboul-Enein, H.Y.; Ali, I. Comparison of the chiral resolution of econazole, miconazole, and sulconazole by HPLC using normal-phase amylose CSPs. Fresenius J. Anal. Chem., 2001, 370(7), 951-955.
[] [PMID: 11569882]
Hoffman, N.E.; Liao, J.C. Separating ability of some polar mobile phases in reverse phase high performance liquid chromatography. Anal. Lett., 1978, 11, 287-306.
Tindall, G.W.; Dolan, J.W. Mobile-Phase Buffers, part II- Buffer Selection and Capacity. LC GC N. Am., 2002, 20, 1114-1118.
Lorenz, L.J. High-Performance Liquid chromatography.Modern methods of pharmaceutical analysis, 2nd ; Schirmer, R.E., Ed.; CRC Press: Boca Raton, 1991, 2, pp. 308-309.
Schoenmakers, P. Programmed analysis.Handbook of HPLC; Katz, E.; Eksteen, R.; Schoenmakers, P.; Miller, N., Eds.; Marcel Dekker: New York, 1998, p. 221..
Khatri, C.K.; Rekunge, D.S.; Chaturbhuj, G.U. Sulfated polyborate: a new and eco-friendly catalyst for one-pot multi-component synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones via Biginelli reaction. New J. Chem., 2016, 40, 10412-10417.
Indalkar, K.S.; Patil, M.S.; Chaturbhuj, G.U. An efficient, environmentally benign, and solvent-free protocol for the synthesis of 4-substituted 1,5-benzodiazepines catalyzed by reusable sulfated Polyborate. Tetrahedron Lett., 2017, 58, 4496-4502.
Patil, M.S.; Mudaliar, C.; Chaturbhuj, G.U. Sulfated polyborate catalyzed expeditious and efficient three-component synthesis of 3-methyl-4-(hetero)arylmethylene isoxazole-5(4H)-ones. Tetrahedron Lett., 2017, 58, 3256-3261.
Khatri, C.K.; Chaturbhuj, G.U. Sulfated polyborate-catalyzed N-formylation of amines: a rapid, green, and efficient protocol. J. Iran. Chem. Soc., 2017, 14, 2513-2519.
Khatri, C.K.; Satalkar, V.B.; Chaturbhuj, G.U. Sulfated polyborate catalyzed Kabachnik-Fields reaction: An efficient and eco-friendly protocol for synthesis of α-amino phosphonates. Tetrahedron Lett., 2017, 58, 694-698.
Rekunge, D.S.; Khatri, C.K.; Chaturbhuj, G.U. Sulfated polyborate-catalyzed efficient and expeditious synthesis of (un)symmetrical ureas and benzimidazolones. Tetrahedron Lett., 2017, 58, 4304-4307.
Rekunge, D.S.; Khatri, C.K.; Chaturbhuj, G.U. Sulfated polyborate: An efficient and reusable catalyst for one pot synthesis of Hantzsch 1,4-dihydropyridines derivatives using ammonium carbonate under solvent free conditions. Tetrahedron Lett., 2017, 58, 1240-1244.
Indalkar, K.S.; Khatri, C.K.; Chaturbhuj, G.U. Rapid, efficient, and eco-friendly procedure for the synthesis of quinoxalines under solvent-free conditions using sulfated polyborate as a recyclable catalyst. J. Chem. Sci., 2017, 129, 141-148.
Indalkar, K.S.; Khatri, C.K.; Chaturbhuj, G.U. Sulfated polyborate: A mild, efficient catalyst for synthesis of N-tert-butyl/N-trityl protected amides via Ritter reaction. J. Chem. Sci., 2017, 129, 415-420.
Khatri, C.K.; Patil, M.S.; Chaturbhuj, G.U. Sulfated polyborate: mild, efficient, and eco-friendly catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones. J. Iran. Chem. Soc., 2017, 14, 1683-1689.
Khatri, C.K.; Mali, A.S.; Chaturbhuj, G.U. Sulfated polyborate catalyzed Kindler reaction: a rapid, efficient, and green protocol. Monatsh. Chem., 2017, 148, 1463-1468.
Indalkar, K.S.; Khatri, C.K.; Chaturbhuj, G.U. Expeditious and efficient synthesis of Strecker’s α-aminonitriles catalyzed by sulfated Polyborate. Tetrahedron Lett., 2017, 58, 2144-2148.
Rekunge, D.S.; Khatri, C.K.; Chaturbhuj, G.U. Rapid and efficient protocol for Willgerodt–Kindler’s thioacetamides catalyzed by sulfated Polyborate. Monatsh. Chem., 2017, 148, 2091-2095.
Patil, M.S.; Palav, A.V.; Khatri, C.K.; Chaturbhuj, G.U. Rapid, efficient, and solvent-free synthesis of (un)symmetrical xanthenes catalyzed by recyclable sulfated Polyborate. Tetrahedron Lett., 2017, 58, 2859-2864.
Patil, M.S.; Khatri, C.K.; Chaturbhuj, G.U. Three-component, solvent-free synthesis of Betti base catalyzed by sulfated Polyborate. Monatsh. Chem., 2018, 149, 1453-1457.
Jejurkar, V.P.; Khatri, C.K.; Chaturbhuj, G.U.; Saha, S. Environmentally benign, highly efficient, and expeditious solvent‐free synthesis of trisubstituted methanes catalyzed by Sulfated Polyborate. ChemistrySelect, 2017, 2, 11693-11696.
Mali, A.S.; Sharma, A.B.; Chaturbhuj, G.U. Sulfated Polyborate catalyzed selective Friedlander annulation for synthesis of highly functionalized quinolines. Org. Prep. Proced. Int., 2020, 52, 297-303.
Mao, Y.; Carr, P.W. Separation of selected basic pharmaceuticals by reversed-phase and ion-exchange chromatography using thermally tuned tandem columns. Anal. Chem., 2001, 73(18), 4478-4485.
[] [PMID: 11575796]
Al-Jammal, M.K.H.; Al Ayoub, Y.; Assi, K.H. Development and validation of microemulsion high performance liquid chromatography (MELC) method for the determination of nifedipine in pharmaceutical preparation. Pharm. Anal. Acta, 2015, 6, 347.
Law, B. Basic drugs: Liquid chromatography.Encyclopedia of Separation Science ; Wilson, I.D.; Adlard, E.R.; Cooke, M.; Poole, C. F., Eds.; Academic Press, 2000, pp. 3701-3708.
Bartha, A.; Vigh, G.; Varga-Puchony, Z. Basis of the rational selection of the hydrophobicity and concentration of the ion-pairing reagent in reversed-phase ion-pair high-performance liquid chromatography. J. Chromatogr. A, 1990, 499, 423-434.
LoBrutto, R.; Jones, A.; Kazakevich, Y.V.; McNair, H.M. Effect of the eluent pH and acidic modifiers in high-performance liquid chromatography retention of basic analytes. J. Chromatogr. A, 2001, 913(1-2), 173-187.
[] [PMID: 11355811]
Jones, A.; LoBrutto, R.; Kazakevich, Y. Effect of the counter-anion type and concentration on the liquid chromatography retention of β-blockers. J. Chromatogr. A, 2002, 964(1-2), 179-187.
[] [PMID: 12198846]
Tindall, G.W.; Dolan, J.W. Mobile-Phase Buffers, part III- Preparation of Buffers. LC GC N. Am., 2003, 21, 28-30.
In, G.N. United States Pharmacopeia, 2018, USP41, 5.
Snyder, L.R.; Kirkland, J.J.; Dolan, J.W. Introduction to Modern Liquid Chromatography.3rd; John Wiley & Sons: New York, 2010;
Stephens, S.J.; Jonich, M.J. Determination of pKa, using the half-volume method: A laboratory experiment. J. Chem. Educ., 1977, 54, 711.
Adoubel, A.A.; Guenu, S.; Elfakir, C.; Dreux, M. Separation of underivatized small peptides on a porous graphitic carbon column by ion-pair chromatography and evaporative light scattering detection. J. Liq. Chromatogr. Relat. Technol., 2000, 23, 2433-2446.
Cox, G.B.; Stout, R.W. Study of the retention mechanism for basic compounds on silica under “pseudo-reversed-phase” conditions. J. Chromatogr. A, 1987, 384, 315-336.
Nawrocki, J. The silanol group and its role in liquid chromatography. J. Chromatogr. A, 1997, 779, 29-71.
McCalley, D.V. Effect of temperature and flow-rate on analysis of basic compounds in high-performance liquid chromatography using a reversed-phase column. J. Chromatogr. A, 2000, 902(2), 311-321.
[] [PMID: 11192164]

Rights & Permissions Print Export Cite as
© 2022 Bentham Science Publishers | Privacy Policy