IonPac CS14 Manual
Doc. No. 034848-10
Page 43 of 54
6.1
High Back Pressure
6.1.1 Finding the Source of High System Pressure
Total system pressure for the IonPac CG14 (4-mm) Guard Column plus the CS14 (4-mm) Analytical Column when using the test
chromatogram conditions should be equal or less than 1,650 psi (11.37 MPa). If the system pressure is higher than 1,750 psi
(12.06 MPa), it is advisable to determine the cause of the high system pressure. The system should be operated with a High-
Pressure In-Line Filter (P/N 044105) which is positioned between the Gradient Pump pressure transducer and the injection
valve. Make sure you have one in place and that it is not contaminated.
A.
Make sure that the pump is set to the correct eluent flow rate.
Higher than recommended eluent flow rates will cause
higher pressure. Measure the pump flow rate if necessary with a stop watch and graduated cylinder.
B.
Determine which part of the system is causing the high pressure.
High pressure could be due to a plugged tubing
or tubing with collapsed walls, an injection valve with a clogged port, a column with particulates clogging the bed
support, a clogged High-Pressure In-Line Filter, the suppressor or the detector cell.
To determine which part of the chromatographic system is causing the problem, disconnect the pump eluent line from
the injection valve and turn the pump on. Watch the pressure; it should not exceed 50 psi (0.34 MPa). Continue
adding system components (injection valve, column(s), suppressor and detector) one by one, while monitoring the
system pressure. The pressure should increase up to a maximum when the Guard and Analytical columns are
connected (see Table 9, “Typical CS14/CG14 Operating Back Pressures”).
The Cation Self-Regenerating Suppressor ULTRA may add up to 100 psi (0.69 MPa). No other components should
add more than 100 psi (0.69 MPa) of pressure. Refer to the appropriate manual for cleanup or replacement of the
problem component.
Table 9
Typical CS14/CG14 Operating Back Pressures
Column
Typical Back Pressure
Flow Rate
psi (MPa)
mL/min
CS14 4-mm Analytical
< 1,200 (8.27)
1.0
CG14 4-mm Guard
< 450 (3.10)
1.0
CS14 + CG14 4-mm columns
< 1,650 (11.37)
1.0
CS14 2-mm Analytical
< 1,200 (8.27)
0.25
CG14 2-mm Guard
< 450 (3.10)
0.25
CS14 + CG14 2-mm columns
< 1,650 (11.37)
0.25