PDA-100 Photodiode Array Detector
3-2
Doc. 031644-02 9/03
•
When changing from a buffer to a different operating mobile phase,
be sure the solvents are miscible and will not induce precipitation of
the buffers. Flush the cell with deionized water immediately after the
analysis; do not let buffers remain in the cell for extended periods.
3.1.2
Solvent Delivery System
•
The pumping system should deliver continuous flow while
maintaining a consistent mobile phase composition (if gradient
elution is used). Fluctuations in system backpressure may cause
baseline disruptions. High sensitivity applications require a smooth,
low-pulsation pump. To ensure optimal results, follow the
maintenance schedule recommended in the pump user’s manual.
•
All materials in the solvent delivery system must be fully compatible
with the mobile phases required for the analysis. For example, IC and
BioLC analyses frequently use mobile phases with extremes of pH or
with high salt concentration. A PEEK pumping system and PEEK
flow cell are required when running these mobile phases because the
presence of stainless steel in the flow path would contaminate the
system.
•
Reversed-phase solvents (methanol, moderate concentrations of
acetonitrile, etc.) are acceptable for a PEEK system. Other solvents
(and high concentrations of acetonitrile) require a stainless steel
system.
•
All tubing connections should be Teflon
®
, Tefzel
®
, PEEK, stainless
steel, or titanium as required for the operating pressures and
application.
•
All mobile phase reservoirs should be compatible with the solvents
used with your application. Some plasticizers in blow-molded
components leach and are strong UV absorbers.
