4
– Example Applications
Thermo Scientific
Product Manual for the ERS 500 Suppressor
Page 44 of 84
031956-11
For Research Use Only. Not for Use in Diagnostic Procedures.
4.
Example Neutralizer Mode Applications
The following examples are presented to highlight the analysis of trace anions or cations found
in the concentrated matrices that have been treated using a Dionex Electrolytically Regenerated
Suppressor (Dionex ERS 500e) in Neutralizer Mode.
The analysis may be done on any one of a number of Dionex anion or cation exchange column
sets. Please refer to the Product Manual for the particular anion or cation exchange column set
installed in your system for detailed operation and troubleshooting information.
Because of its low operating pressure, the Dionex UTAC-XLP2 (Item # 072781) or Dionex
TCC-XLP1 (Item # 063889) should be used to concentrate the trace anions or cations in the
sample neutralized by the Dionex ERS 500e. The use of other concentrators may result in
excessive back pressure to the Dionex ERS 500e, thus damaging the Dionex ERS 500e.
The Dionex ERS 500 suppressor is not recommended for use with the Neutralization Mode
of Operation. The Dionex ERS 500e should be used.
4.1
System Blank
4.1.1
Anion System Blank
Trace anion contamination in the deionized water used for the carrier solution, the Dionex
AERS 500e and eluent create the analytical blank. For trace analysis, the analytical blank
usually determines the detection limits of the system. Anion contaminants in deionized water
can be removed by installing Dionex IonPac ATC-HC column between the sample carrier pump
and the Sample Valve. The major source of sulfate contamination is usually from the Dionex
AERS 500e. Since this device uses high capacity surface sulfonated ion exchange screens and
membranes, sulfate is released from the screen and membrane surfaces, especially in a newly
installed Dionex AERS 500e.
To reduce the sulfate blank, follow the Dionex ERS 500e startup procedure in Section 3.3,
“Start-up Procedure for the Dionex Electrolytically Regenerated Suppressor (Dionex ERS
500e).” The sulfate blank is normally reduced to a constant level after 24 hours of operation.
Typical blanks are shown in Figure , “Dionex IonPac AS11 Gradient Analysis of Blank,
Standard, 10% NaOH Sample and spiked 10% NaOH Sample” and Figure , “Dionex IonPac
AS12A Isocratic Analysis of Blank, Standard, 25% NaOH Sample and Spiked 25% NaOH
Sample.” Finally, anion contaminants in the eluent (e.g., Na2CO3/NaHCO3 and NaOH) also
contribute to the analytical blank. A choice of high purity chemicals helps to reduce the blank
concentrations.
4.1.2
Cation System Blank
Trace cation contamination in the deionized water used for the carrier solution, the Dionex
CERS 500e and eluent create the analytical blank. For trace analysis, the analytical blank
usually determines the detection limits of the system. Cation contaminants in deionized water
can be removed by installing Dionex CTC-1 Column between the sample carrier pump and the
Sample Valve. The major source of ammonia and amine contamination is usually from the
Dionex CERS 500e. Since this device uses high capacity aminated ion exchange screens and
NOTE
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