Ionizable Modifier Chromatographic Materials for pH Stability
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Solution Overview
Problem
Current chromatographic materials, such as silica and hybrid materials, face issues with poor peak shape for bases at low pH and changes in analyte retention times when exposed to repeated pH changes in liquid chromatography, leading to reduced loadability and peak capacity.
Innovation Solution
Development of high purity chromatographic materials with a hydrophobic surface group and ionizable modifiers, specifically excluding quaternary ammonium ions, which provide improved stability and retention characteristics across varying pH conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silica or hybrid materials are used as chromatographic packing materials, then high efficiency and mechanical stability are achieved, but poor peak shape for bases occurs at low pH and retention time drift occurs after repeated pH changes
Solution Approach 1:
The invention modifies the surface chemistry parameters of the chromatographic material by introducing ionizable modifier groups (carboxylic acid, sulfonic acid, phosphoric acid, boronic acid, amino, imido, amido, pyridyl, imidazolyl, ureido, or aminosilane groups) that can protonate or deprotonate depending on pH conditions. This dynamic parameter change allows the material to maintain optimal interaction characteristics across different pH ranges, resolving the peak shape issues at low pH and retention stability issues during pH transitions.
Solution Approach 2:
The invention creates a composite chromatographic material by combining the base silica or hybrid material structure with surface-grafted ionizable modifier groups. This composite approach integrates the mechanical stability and high efficiency of silica with the pH-adaptive surface chemistry of ionizable groups, achieving both structural reliability and operational ease across varying pH conditions.
2Strength
If conventional chromatographic materials are used, then good mechanical strength is maintained, but column efficiency decreases for low molecular-weight analytes
Solution Approach 1:
The invention applies local quality modification by maintaining the robust silica core structure for mechanical strength while introducing ionizable modifier groups specifically at the surface level where analyte interactions occur. This localized functionalization ensures that the bulk material provides mechanical support while the surface provides optimized separation characteristics for high column efficiency.
3Stability of the object's composition
If organic chromatographic materials are used, then chemical stability against strongly alkaline and acidic mobile phases is achieved, but columns exhibit shrinking and swelling behavior
Solution Approach 1:
The invention creates a composite structure combining the dimensional stability of inorganic silica with the chemical stability of organic ionizable modifier groups. The silica framework provides rigid structural support that prevents shrinking and swelling, while the grafted organic modifier groups provide chemical stability across a wide pH range, resolving both issues simultaneously.
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
The new materials exhibit enhanced peak shape and reduced retention time drift, resulting in improved chromatographic performance and stability across a wide pH range.
Implementation Method 1
the chromatographic surface comprises a hydrophobic surface group and one or more ionizable modifiers
Implementation Method 2
the chromatographic surface comprises a hydrophobic surface group
Data Source
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Figure 3(a)~3(c)
AI summary
The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for its preparation and separations devices containing the chromatographic material; separations devices, chromatographic columns and kits comprising the same; and methods for the preparation thereof. 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.