Anion system blank - ERD 500 - ERS 500e - ERS 500 Carbonate - DRS 600 - Anion system blank - ERD 500 - ERS 500e - ERS 500 Carbonate - DRS 600

Trace anion contamination in the deionized water used for the carrier solution, the Dionex ADRS 600 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 ADRS 600. 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 ADRS 600.

To reduce the sulfate blank, follow the Dionex DRS 600 startup procedure in Start-up. The sulfate blank is normally reduced to a constant level after 24 hours of operation. Typical blanks are shown in Dionex IonPac AS11 Gradient Analysis of 10% Sodium Hydroxide.

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.