Fig. 1 Electropherogram obtained under optimized conditions for the
analysis of nitrate and nitrite. Concentration of each anion, 10 mg L−1.
Separation conditions: fused silica capillary column, 75-μm i.d.×360-
μm o.d., 48.5-cm total length (40 cm to detector); running buffer,
60 mmol L−1 borate and 0.2 mmol L−1 CTAB; hydrodynamic
injection, 12 s at 30 mbar; separation voltage, −10 kV; T=29 °C;
direct UV detection at 210 nm. Peak labels: 1 Nitrite, 2 Nitrate, 3
Sulfite (internal standard