Comparison of isocratic retention models for hydrophilic interaction liquid chromatographic separation of native and fluorescently labeled oligosaccharides

Abstract

In this work, we have investigated retention of maltooligosaccharides and their fluorescent derivatives in hydrophilic interaction liquid chromatography using four different stationary phases. The non-derivatized maltooligosaccharides (maltose to maltoheptaose) and their derivatives with 2-aminobenzoic acid, 2-aminobenzamide, 2-aminopyridine and 8-aminonaphthalene-1,3,6-trisulfonic acid were analyzed on silica gel, aminopropyl silica, amide (carbamoyl-bonded silica) and ZIC-HILIC zwitterionic sulfobetain bonded phase. The partitioning of the analytes between the bulk mobile phase and adsorbed water-rich layer, polar and ionic interactions of analytes with stationary phase have been evaluated and compared. The effects of the mobile phase additives (0.1% (v/v) of acetic acid and ammonium acetate in concentration range 5-30 mmol L(-1)) on retention were described. The suitability of different models for prediction of retention was tested including linear solvent strength model, quadratic model, mixed-mode model, and empirical Neue-Kuss model. The mixed-mode model was extended to the parameter describing the contribution of monomeric glucose unit to the retention of non-derivatized and derivatized maltooligosaccharides, which was used for evaluation of contribution of both, oligosaccharide backbone and end-group to retention.

Optimizing separations in online comprehensive two‐dimensional liquid chromatography

“…A crucial aspect of using predictive tools is experimental verification to validate the established retention parameters. For example, for HILIC it is known that the stationary and mobile phase, significantly influence the type of interactions between analyte and stationary‐phase packing . As a result, the selected retention model may not adequately describe the retention behavior, resulting in incorrect predictions.…”

“…See Supporting Information S3 for a more detailed clarification on the chromatographic conditions, analyte mixture, and the optimization parameters used to arrive at this PO-plot. Plot created using the Program for Interpretive Optimization of 2D Resolution (PIOTR) [187] and mobile phase, significantly influence the type of interactions between analyte and stationary-phase packing [105,188]. As a result, the selected retention model may not adequately describe the retention behavior, resulting in incorrect predictions.…”

Mobile phase effects on the retention on polar columns with special attention to the dual hydrophilic interaction–reversed‐phase liquid chromatography mechanism, a review

“…Equation (12) provides improved fit to the experimental HILIC data of oligosaccharides with respect to the two-parameter model equations (Eqs. (10) and (11)) [60]. In spite of different conclusions of some studies, it is highly probable that the adsorption and the partition retention mechanisms actually coexist in HILIC.…”

Variability of temperature dependences of the retention of strongly polar compounds under ZIC‐HILIC liquid chromatographic mechanism

“…Retention of polar analytes on HILIC stationary phase depends on the intesity of polar interactions between polar groups of analytes and polar moieties from stationary phase . At their turn, these interactions depend on the composition of the mobile phase and temperature . Zwitterionc liquid chromatography (ZIC‐HILIC) is a particular HILIC mechanism in liquid chromatography that uses a stationary phase containing both anionic and cationic groups in their structure, such as embedded quaternary amine and sulfonic or carboxyl terminal groups .…”