Hollow-fiber suppressor conductivity

Fig. 3-38. Comparison of detection sensitivities for the application of a conventional suppressor column and a hollow fiber suppressor. — Separator column IonPac AS4 eluent 0.0028 mol/L NaHC03 + 0.0022 mol/L Na2C03 flow rate 2 mL/min detection conductivity with a) ASC-1, and b) hollow fiber suppressor AFS-1 regenerent 0.0125 mol/L H2S04 injection 50 pL anion standard.

The regeneration of a micromembrane suppressor occurs in much the same way as for a hollow fiber suppressor. The regenerent is delivered pneumatically from the reservoir, since the required flow rate cannot be obtained simply via gravity feed. While a sulfuric acid concentration of c = 0.01 mol/L suffices for isocratic operation, a twofold regenerent concentration is recommended for gradient techniques. The flow rate should be adjusted to ensure a sufficiently low background conductivity when the maximum eluent conentration is reached. Maintaining these conditions, one can then switch to the initial eluent concentration. 

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