VDSpher® Chromatography columns

Significance of the Topic

Liquid chromatography remains the workhorse of analytical chemistry, underpinning quality control in pharmaceuticals, environmental monitoring, food analysis and biochemistry. The choice of stationary phase directly influences selectivity, resolution and robustness. Modern applications demand materials that perform reliably from the nano-gram scale in UHPLC to multi-gram loads in preparative separations. VDSpher phases offer a versatile portfolio to meet diverse separation challenges.

Objectives and Study Overview

This document presents an overview of the VDSpher product family, detailing silica-based separation phases introduced by VDS optilab since 2007 and expanded in 2024 with the VDSpher II line. Key goals are to compare base silica purity (Classic vs. PUR), pore sizes, particle diameters (1.8–10 µm), surface chemistries (normal, reversed, HILIC, bio-phases) and to demonstrate chromatographic performance across analytical, UHPLC and preparative scales.

Methodology and Instrumentation

Separation phases were characterised by their pore size (100 Å, 120 Å, 300 Å), surface area, pore volume, metal content (<100 ppm for Classic, <20 ppm for PUR, <10 ppm for II) and carbon loading. Functional groups include unmodified silica, alkyl chains (C4, C8, C18 monomeric/polymeric), phenyl, diol, CN, amino and zwitterionic modifications. Endcapping approaches (liquid, gas, mixed) tune silanol activity. Performance evaluations employed:

• Reversed-phase isocratic runs with UV detection
• Engelhardt test for hydrophobic and silanophilic selectivity
• Plate count determinations in UHPLC format
• HILIC separations of polar analytes
• Preparative column packing trials

Main Findings and Discussion

• Base silica purity strongly affects retention: PUR phases with low metal content reduce unwanted analyte–metal interactions and offer consistent selectivity.
• Monomeric vs. polymeric bonding and endcapping modality govern hydrophobicity, silanol activity and pH stability (range pH 1–10 depending on phase).
• VDSpher II shows enhanced surface area (450 m2/g), pore volume (1.1 mL/g) and ultra-low metal content, delivering sharper peaks, broader pH tolerance and embedded polar-group selectivity.
• U-VDSpher PUR (1.8 µm) meets UHPLC demands, achieving plate counts >15 000 in sub-3 min runs at 380 bar.
• Core Shell Mode (CSM) phases (2.5 µm) combine high efficiency with moderate back pressure, bridging the gap between 3 µm and sub-2 µm materials.
• Specialized phases (OptiAqua, OptiBio, PUR HILIC) enable 100 % aqueous elution, biomolecule profiling and hydrophilic interaction chromatography for nucleobases, peptides and sugars.

Benefits and Practical Applications

VDSpher phases deliver:

• Outstanding batch-to-batch reproducibility
• Broad selectivity toolkit for polar, non-polar, aromatic and ionic species
• High chemical stability across long pH and temperature windows
• Chromatographic scalability from UHPLC to preparative HPLC
• Optimized endcapping for alkaline and chelating compound analysis

Typical applications span pharmaceutical impurity profiling, natural product isolation, environmental trace analysis and proteomics.

Future Trends and Potential Uses

Emerging directions include further miniaturization for nano-LC, advanced core–shell architectures with tailored pore networks, integrated polar embedded phases for seamless water-only operation, and expansion of biocompatible chemistries for protein, antibody and oligonucleotide separations. Sustainable chromatography will drive lower solvent consumption and recyclable phase designs.

Conclusion

The VDSpher family constitutes a comprehensive platform of silica-based stationary phases covering normal, reversed, HILIC and bio-analytical modes. With precise control of particle and pore characteristics, surface chemistry and endcapping, these materials satisfy rigorous analytical and preparative demands, offering high performance, reproducibility and flexibility for modern chromatographic workflows.