ANIONS: IC columns used with chemical suppression

Carbonate eluent (standard eluent)

Sodium hydrogen carbonate: 1.0 mmol/L ;168 mg/2 L
Sodium carbonate: 3.2 mmol/L ; 678 mg/2 L

Hydroxide eluent, modified

Sodium hydroxide: 120.0 mmol/L ; 600 mg/2 L
p-Cyanophenol: 4.0 mmol/L ; 476 mg/2 L

Chromate eluent

Sodium hydrogen carbonate: 4.0 mmol/L ; 168 mg/2 L
Sodium carbonate: 12.8 mmol/L ; 2712 mg/2 L

Contamination by low-valency hydrophilic ions:

a) Rinse with ultrapure water (25 min at 0.3 mL/min)
b) Rinse with 10-fold concentrated eluent (100 min at 0.3 mL/min)
c) Rinse with ultrapure water (25 min at 0.3 mL/min)
d) Rinse with eluent (100 min at 0.3 mL/min)

Contamination by high-valency hydrophilic ions:

a) Rinse with ultrapure water (25 min at 0.3 mL/min)
b) Rinse with 5% acetonitrile (20 min at 0.3 mL/min)
c) Rinse with 100% acetonitrile (60 min at 0.3 mL/min)
d) Rinse with 50% acetonitrile (10 min at 0.3 mL/min)
e) Rinse with ultrapure water (50 min at 0.3 mL/min)
f) Rinse with eluent (100 min at 0.3 mL/min)

System peak shifted (regeneration method with column oven):

a) Rinse with concentrated eluent 1 mol/L (25 min at 0.4 mL/min)
b) Keep at 45 ... 50 °C for 10 ... 12 hours (no rinsing)
c) Rinse with standard eluent (minimum 40 min at 0.4 mL/min)

Applications

• standard anions
• F^-, Cl^-, Br^-, I^-
• ClO₂^-, ClO₃^-, ClO₄^-, BrO₃^-
• ClO₄^-
• BrO₃^-
• Cr (VI) (CrO₄^2-)
• method development
• difficult matrices
• difficult separating problems