The Thermo Scientific Dionex UltiMate^™ 3000 Quaternary Rapid Separation Pump LPG-3400RS provides the highest degree of flexibility in solvent proportioning for UHPLC applications. This pump is recommended for a wide range of research and routine applications, and for method development.

• Serial dual-piston operating principle, low-pressure gradient proportioning
• Wide operating flow rate range from 100 μL/min to 8 mL/min with high flow rate accuracy
• Support of operating pressures of up to 1034 bar (15,000 psi)
• SmartFlow^™ technology automatically ensures optimal chromatographic performance at any operation condition
• Automatic compressibility compensation, no manual solvent setting needed
• Unique SpinFlow^™ mixing design perfectly balances gradient delay volume against mixing efficiency
• Extensive mixer portfolio (35–1550 μL) to cover all application needs
• Reliable vacuum degassing with an internal four-channel micro membrane degasser
• Active rear-seal wash for maximum seal lifetime, and reduced instrument down time

The LPG-3400RS is recommended for any UHPLC and conventional LC applications in the pharmaceutical, food and beverage, and environmental industries.

Optimum Mixing of Solvents with the UltiMate RSLC Pump

Ultrafast gradient separations require a small gradient delay volume to ensure the gradient is correctly applied to the column. However, high mixing volumes are typically required to ensure the mobile phase components are completely mixed.This is particularly important when working with UV detectors, as incomplete mixing may lead to ripple effects in the chromatography baseline.

With very fast separations even small fluctuations in the mobile phase composition can compromise the precision of the peak retention time. Therefore, complete mixing is necessary to achieve a constant, flat baseline, high signal-to-noise ratios, and accurate peak identification.

Different types of applications have different requirements regarding mixing efficiency. Some require almost no mixing, while others require additional mixing volume to achieve a smooth baseline. A water/acetonitrile gradient using TFA as a modifier is an example of this type of gradient that requires precise mixing efficiency

The new proprietary mixing concept from Dionex addresses all these needs with:

• A two-step process of radial mixing followed by longitudinal mixing to ensure the highest possible mixing efficiency.
• Mixing volume that can be easily adapted to fit specific method requirements. The default mixing volume (400 µL) can be easily changed using mixing kits of 35, 200, 800, or 1500 µL (effective mixing volume).
• Available for the UltiMate^® 3000 Binary, Quaternary, and Dual-Gradient RSLC pumps providing ultrahigh resolution and ultrafast separations.