IonPac NS1 Manual
Document No. 034024-06
Page 26 of 35
Standard
Column
Typical Back Pressure
Flow Rate
psi (MPa)
mL/min
IonPac NS1 analytical
900 (6.21) - 1,400 (9.66)
1.0
IonPac NG1 guard
200 (1.38) - 300 (2.07)
1.0
IonPac
NS1 + NG1 columns
1,100 (7.59) - 1,700 (11.73)
1.0
IonPac NS1-5 µm analytical
1,700 (11.73) - 2,500 (17.24)
1.0
IonPac NG1 guard
200 (1.38) - 300 (2.07)
1.0
IonPac
NS1-5
µ
m + NG1 columns
1,900 (13.11) - 2,800 (19.31)
1.0
5.1
High Back Pressure
5.1.1 Finding the Source of High System Pressure
Total system pressure when using the IonPac NG1 Guard and IonPac NS1 analytical columns at 1.0 mL/min should be less than
1,600 psi (11.03 MPa) when using the eluent used to generate the test chromatogram. Total system pressure when using the IonPac
NG1 Guard and IonPac NS1 analytical columns at 2.0 mL/min should also be less than 1,600 psi (11.03 MPa) when using the eluent
used to generate the test chromatogram. If the system pressure is higher than 1,600 psi (11.03 MPa), it is advisable to find out what
is causing the high system pressure.
The system should be used with a High-Pressure In-Line Filter (P/N 035331) for eluents.
The filter should be positioned
between the gradient pump pressure transducer and the injection valve. Since the liquid lines on the gradient pump have 10-32
ferrule/bolt fittings and the High-Pressure In-Line Filter has one male 1/4-28 fitting and one female 1/4-28 port, it is necessary
to install two adaptor assemblies on the filter. On the end of the filter with the 1/4-28 male fitting, place a 1/4-28 to 10-32 union
(P/N 042806). On the end of the filter with the 1/4-28 female port place a 1/4-28 male to 10-32 female port adaptor assembly (P/
N 043291). Make sure you have a High-Pressure In-Line Filter 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. Find out what part of the system is causing the high pressure.
It could be a piece of tubing that has plugged or whose
walls are collapsed, an injection valve with a plugged port, a column with particulates plugging the bed support, a
plugged High-Pressure In-Line Filter, the suppressor, or the detector cell.
To find out 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 the system’s components
(injection valve, column(s), suppressor, and detector) one by one, while watching the system pressure. The pressure should increase
up to a maximum of 1,500 psi (10.34 MPa) at a flow rate of 2.0 mL/min when the column(s) are connected. The suppressor 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 5
Typical NS1/NG1 Operating Back Pressures
