Recommended Fittings for HPLC and LC‑MS Columns: Why Choose the Di‑Ad™ Connector

Selecting the right fitting for an HPLC or LC‑MS column is essential for ensuring leak‑free operation, maintaining chromatographic efficiency, and simplifying column changes. MICROSOLV recommends using Direct Adaptive Di‑Ad™ column connectors in place of conventional fittings that require repeated ferrule re‑swaging whenever a column is removed or replaced.

The Di‑Ad™ system provides a reliable, easy‑to‑use mechanical interface that improves consistency and reduces downtime—making it ideal for laboratories that routinely change columns or alternate between different stationary phases.

Why MICROSOLV Recommends Di‑Ad™ Over Re‑Swaged Fittings

1. Eliminates the Need for Ferrule Re‑Swaging

Standard HPLC fittings often rely on metal or polymer ferrules that permanently deform when tightened. Each time a column is replaced, the ferrule may need to be re‑cut or re‑swaged, which can:

• Create variability in seating depth
• Increase risk of leaks
• Introduce potential dead volume
• Cost time and material during frequent column changes

The Di‑Ad™ connector avoids these issues entirely, enabling a clean, repeatable installation every time.

2. Ideal for Standard Cogent Phases (4 µm & 2.o™ Columns)

MICROSOLV specifically highlights Di‑Ad™ connectors as the preferred choice for its Cogent-type columns—both the standard 4 µm and advanced 2.o™ stationary phases. These columns benefit greatly from consistent, low‑dead‑volume connections, particularly when switching between column chemistries or guard cartridges.

The Di‑Ad™ design helps maintain chromatographic fidelity by ensuring:

• Proper seating depth
• Excellent peak shape
• Reduced risk of dead‑volume‑related distortions

3. Supports Clean, Easy, and Fast Column Changes

The Di‑Ad™ connector is engineered for tool‑free, user‑friendly operation. Its design minimizes the chance of damaging ferrules, fittings, or column hardware during repeated changes. This is especially beneficial in:

• High‑throughput analytical labs
• Method development environments
• Multimethod LC‑MS suites where columns are rotated frequently

Important Limitation: Not Recommended for UHPLC

While Di‑Ad™ connectors work exceptionally well for HPLC and LC‑MS, MICROSOLV notes an important limitation:

❌ Do NOT use Di‑Ad™ or PEEK fittings for UHPLC.

Due to the extremely high pressures associated with UHPLC (>15,000 psi in many systems), polymer‑based or adaptive fitting systems are not suitable. Stainless‑steel hardware specifically designed for UHPLC is required to avoid leaks or fitting failures.

When to Use Di‑Ad™ Connectors vs. Other Fittings

Additional Resources

Ordering information and images for the Di‑Ad™ column connector are available through the this website:  Click HERE for Di-Ad™ column connector information and pictures.