Exploring Injection Principles; Defining Pressure-Assisted Sample Aspiration - Waters 2707 Operator's Manual

Exploring injection principles

The autosampler has three injection modes:
• Full loop– For maximum injection volume precision
• Partial loop needle overfill – For maximum flexibility
• Partial loop – For zero sample loss

Defining pressure-assisted sample aspiration

For all injection modes, the instrument method can enable loop injection with
pressure-assisted sample aspiration. This option pairs an on-board
compressor with intelligent valve switching and highly accurate syringe
control, resulting in these benefits:
• Helps aspirate viscous samples
• Reduces the risk of bubbles in the sample line
• Prevents unwanted sample movement in the needle
Pressurizing vial
Syringe
1-6 Understanding Operating Principles
Buffer tubing
Air pressure
HPLC pump
Sample loop
HPLC column