High-Purity Stationary Phases for MS-Compatible Acidic Analyte Retention
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Solution Overview
Problem
Current chromatographic techniques face challenges in effectively retaining and selectively isolating acidic, polar analytes such as organic acids, sugars, and phosphorylated compounds, often requiring ion-pair reagents, ion chromatography, or hydrophilic interaction chromatography, which can be incompatible with mass spectrometric detection and limited by sample or diluent restrictions.
Innovation Solution
A method using high purity chromatographic materials with a hydrophobic surface group and ionizable modifiers, excluding quaternary ammonium ions, to selectively adsorb and elute acidic, polar molecules like succinic acid, malic acid, and others, by adjusting pH, facilitating their isolation and analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion-pair reagents are used to retain acidic analytes, then retention is improved, but compatibility with mass spectrometric detection deteriorates
Solution Approach 1:
The patent introduces a stationary phase with embedded basic groups (such as amine-functionalized silica) as an intermediary mechanism. Instead of using ion-pair reagents in the mobile phase that interfere with MS detection, the basic groups are permanently embedded in the stationary phase to provide ion-exchange retention for acidic analytes. This separates the retention function (performed by the stationary phase) from the detection function (performed by the MS), allowing compatibility between both.
2Reliability
If ion chromatography is used to retain acidic analytes, then retention is improved, but device complexity and specialized equipment requirements increase
Solution Approach 1:
The patent combines reversed-phase chromatography and ion-exchange chromatography into a single stationary phase system. The stationary phase contains both hydrophobic groups (for reversed-phase retention) and embedded basic groups (for ion-exchange retention of acidic analytes). This merging of two chromatographic mechanisms into one system eliminates the need for separate ion chromatography equipment while achieving retention of acidic analytes.
3Reliability
If hydrophilic interaction chromatography is used to retain acidic analytes, then retention is improved, but sample and diluent restrictions increase
Solution Approach 1:
The patent changes the fundamental retention mechanism from hydrophilic interaction (HILIC) to a combined reversed-phase/ion-exchange mechanism. By embedding basic groups in the stationary phase, the system achieves retention of acidic analytes through ion-exchange interactions rather than relying on hydrophilic interactions that require specific sample and diluent conditions. This parameter change in the retention mechanism broadens sample and diluent compatibility.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances retention and selectivity for acidic, polar molecules, allowing for improved analysis through LC and LC-MS without the need for specialized equipment, while maintaining compatibility with mass spectrometric detection.
Implementation Method 1
the chromatographic surface comprises a hydrophobic surface group and one or more ionizable modifiers such that the acidic, polar molecule is selectively adsorbed
Implementation Method 2
the chromatographic surface comprises a hydrophobic surface group and one or more ionizable modifiers
Implementation Method 3
wherein the acidic, polar molecule is eluted by an upward shift in pH
Data Source
Figure 1
Figure 2
Figure 3(a)~3(c)
AI summary
The present invention provides the use of charged surface reversed phase chromatographic materials along with standard reversed-phase LC and mass spectrometry compatible conditions for the retention, separation, purification, and characterization of acidic, polar molecules, including, but not limited to, organic acids, α-amino acids, phosphate sugars, nucleotides, other acidic, polar biologically relevant molecules. The chromatographic materials of the invention are high purity chromatographic materials comprising a chromatographic surface wherein the chromatographic surface comprises a hydrophobic surface group and one or more ionizable modifier.