Retention characteristics of some antibiotic and anti-retroviral compounds in hydrophilic interaction chromatography using isocratic elution, and gradient elution with repeatable partial equilibration

Abstract

Retention characteristics of some antibiotic and antiretroviral compounds in hydrophilic interaction chromatography using isocratic elution, and gradient elution with repeatable partial equilibration. ANALYTICA CHIMICA ACTA.

Determination of d-Cycloserine Impurities in Pharmaceutical Dosage Forms: Comparison of the International Pharmacopoeia HPLC–UV Method and the DOSY NMR Method

“…The dimer was also shown to exist in a pH-dependent equilibrium (pH 1-2) with cycloserine [22]. The addition of citrate or ethylenediaminetetraacetic acid into the mobile phase might prevent the potential on-column dimerization of d-cycloserine, as reported by Heaton et al (2019) [24]. Therefore, a future study, where the sample solvent and the pH are carefully controlled might solve some of the issues with the quantification of d-cycloserine and its related substances in pharmaceutical dosage forms.…”

“…However, it has become imperative to purify cycloserine from the dimer, which is nowadays considered to be a contaminant [23]. Recently, a new study reported on severe peak tailing of a d-cycloserine peak, due to its on-column dimerization, promoted by stationary phase metal oxides, which was resolved by addition of citrate (chelating agent) to the HILIC mobile phase [24].…”

High-Throughput and Ultrafast Liquid Chromatography

“…The former approach has been most effective to utilizing reversed phase columns in the second dimension with only 2–3 column volumes required to achieve high retention time repeatability. − Hydrophilic interaction chromatography (HILIC) has not been utilized as frequently for high-speed separations in the second dimension or for ultrafast separations in general, partially due to the perceived need for lengthier re-equilibration times to achieve retention time repeatability . However, recent results on this topic have demonstrated that partial re-equilibration strategies compatible with reversed phase columns can also be implemented with HILIC columns, with re-equilibration times as short as 3 s being feasible on shorter columns typical of ultrafast methods. − …”

Impact of conditioning runs on hydrophilic interaction chromatography repeatability and its application as a second dimension in online comprehensive two‐dimensional liquid chromatography

“…The HILIC technique relies on the adsorption of a water layer on the stationary phase, necessitating extended equilibration times, especially when used in gradient mode. For example, the literature suggests a minimum of 40 column volumes for a complete equilibration, depending on the stationary phase and solutes [4,5]. Nevertheless, shorter partial equilibration periods are also feasible [4,[6][7][8].…”

“…For example, the literature suggests a minimum of 40 column volumes for a complete equilibration, depending on the stationary phase and solutes [4,5]. Nevertheless, shorter partial equilibration periods are also feasible [4,[6][7][8]. For example, McCalley showed that an equilibration step of 12.2 column volumes yields satisfactory retention time repeatability [6], while even as few as five column volumes were sufficient for consistent separation of antibiotic and antiretroviral compounds [4].…”