Mobile Phase Delivery System; Flow Cells - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

4.6.2 Mobile Phase Delivery System

The pumping system should deliver continuous flow while ensuring intermixing of the mobile
phase (if gradient elution is used). Fluctuations in pump backpressure can cause baseline
noise. If the noise is synchronized with the pump stroke, check your HPLC pump.
The plastics present in some solvent delivery systems from third-party manufacturers are not
fully compatible with the solvents commonly used in chromatography. Therefore, plastic
components may dissolve, and thus impair fluorescence detection.
For UV wavelengths, these guidelines are recommended:
• The mobile phase reservoir should be glass.
• All tubing connections should be made of materials suitable for HPLC applications (for
example, PTFE, ETFE, PEEK, stainless steel, or titanium), as required for the operating
pressures and application.
• Some pump seals incorporate a band spring to preload the seal during the vacuum stroke
of the piston. The band spring should be made of stainless steel, a fluoropolymer
(perfluoroelastomer or fluorosilicone), or another material of known quality.
If you are working with an UltiMate 3000 system, using original Dionex parts only, all the
above recommendations are met.

4.6.3 Flow Cells

To ensure optimum performance of the flow cells, observe the following guidelines:
• The backpressure on the flow cell must not exceed 20 bar (analytical flow cell) or 40 bar
(micro flow cell). Do not connect any capillaries or instruments to the flow cell out line
as this might generate a higher backpressure. Even if the pressure exceeds the upper limit
for a very short time only, the flow cell may be permanently damaged. If it is required to
connect a valve at the flow cell outlet, the valve may only be switched while the flow is
stopped. When switching valves while the flow is turned on, pressure peaks may occur
and destroy the flow cell. Thermo Fisher Scientific recommends using a capillary or tube
with an internal diameter of at least 0.5 mm at the flow cell out line.
• When connecting the flow cells, make sure not to invert input and output. This will
deteriorate the measured results and may destroy the flow cell due to the increased
backpressure in the cell.
• The contacts for the flow cell identification chip and the temperature control are located
on the rear of the flow cell. To ensure proper functionality, be careful not to touch the
sensitive electronics. If liquid comes into contact with the electronics, dry it immediately.
Operating Instructions
Fluorescence Detectors FLD-3100 and FLD-3400RS
UltiMate 3000 Series:
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