ProtumLink Union Series
ProtumLink Union 50cm
Product Description
Maximum Resolving Capacity
Core Benefit: Ultra-Deep PTM and Structural Proteomics
The 50 cm column is the most resolving option in the series, intended for the highest-depth analyses, where maximum peak capacity and sensitivity are required.
Chromatographic Excellence (FWHM Resolution)

Measured at 250 nL/min, the column achieves ~5.7 s FWHM over ~95 min gradients, offering the separation space necessary to distinguish low-abundance and closely eluting peptides. This is particularly impactful for PTM mapping, deep clinical proteomics, and complex structural studies.
Backpressure Flexibility & Workflow Versatility
With an operational range of 100–400 nL/min, the 50 cm column performs reliably over long analytical sequences and requires stable UHPLC pressure capability. It is the preferred option when analytical depth, precision, and confidence take priority over throughput.
Pressure profiles

Compatibilities
Union columns feature an integrated liquid junction that enables straightforward connection to nano-LC systems using standard 10-32 threaded fittings. This configuration provides a robust, zero-dead-volume interface and allows fast column exchange without additional adapters. The integrated junction can also serve as the grounding or high-voltage application point when required by the instrument configuration. Union columns are fully compatible with setups using Thermo Scientific Nanospray Flex ion sources, where the high voltage can be applied through the liquid connection. This standardized connectivity enables a direct and reliable link between the column outlet and the UHPLC system while preserving excellent chromatographic performance. Specific adapter configurations may be required depending on the vendor ion source when operating emitter-integrated columns with a pre-mounted liquid junction. Users should consult instrument documentation where compatibility with blank-emitter columns is explicitly described.
Compatible Connection Systems
• Thermo Scientific nanoViper™ Fingertight Fittings • IDEX Health & Science MarvelXACT™ UHPLC Connection Systems • Waters ZenFit™ Connection Technology (compatibility pending verification)
C18 Bead Specification
Specification Table
| Property | Specification |
|---|---|
| Silica Brand | ReproSil-Pur 120 C18-AQ (Dr. Maisch GmbH) |
| Chromatographic Mode | Reversed-phase |
| Particle Size | 1.9 µm |
| Pore Size | 120 Å |
| Surface Area | 300 m²/g |
| Bonding / Phase | C18 (ODS), fully end-capped, aqueous-compatible |
| Carbon Load | 15% |
| pH Stability Range | 2 – 8 |
| Max Operating Pressure | ≤ 1200 bar |
| Max Operating Temperature | 60 °C* |
*Ultra-fast gradients may be operated up to 70 °C.
Why We Use a Trusted C18 Phase
We rely on a well-established C18 material from Dr. Maisch because it has been widely used in LC–MS–based proteomics for nearly two decades and is known for its stable bonding chemistry, consistent material quality, and reproducible performance. This makes it a dependable foundation for achieving high-quality peptide separations across diverse workflows. The 1.9 µm C18 particles provide a balanced combination of peak capacity, mechanical robustness, and retention stability, supporting sharp and predictable peak shapes under the aqueous mobile-phase conditions typical for proteomics.
Application Notes
Ultra robust performance stability of 25 cm × 75 µm Emitter-Integrated Nanoflow Column with 1.9 µm C18 Material over 800 Samples
PDF - 1.5 MB
High-Sensitivity and Reproducible DIA Performance of a 15 cm × 75 µm Emitter-Integrated Nanoflow Column on the Orbitrap Astral System
PDF - 1.1 MB
Packages
Column ID (Diameter)

