Separation of Test Mixture Containing Nitrate, Nitrite & Oxalic Acid
Organic acids and anions play an essential role in both environmental and biological processes. Determination of
these molecules is important for both quality control and research laboratories. This application note shows the
efficiency of CElixirOA to separate Nitrites from Nitrates and Oxalic Acid using pH 2.5.
Capillary: MicroSolvCE Bare Fused Silica, 75µm x 60cm
Injection: 5 sec pressure
Run Buffer: CElixirOA pH 2.5 Kit
Detection: UV 200nm
Polarity: Reverse Mode
Using a Beckman P/ACE MDQ HPCE System and 75µm ID bare fused silica capillary, the analysis and
separation of Nitrate from Nitrite from Oxalic Acid is easily achieved. The concentration of the analytes was below
10mg/ml and was hydrodynamically injected for 5 seconds. The capillary was conditioned according the
CElixirOA manual. The separation was completed in less than 5 minutes.
Discussion and Rationale:
Many small anions are UV absorbing and the proper choice of the absorbing background electrolyte is important for
good peak shape and sensitivity. CElixirOA pH 2.5 Kit contains phosphoric acid as the background electrolyte. Using
a polycationic, dynamic coating technology of CElixir the separation shown is possible and easy with no hassles of
mixing solutions or preparing any run buffers on your own. There is no problem determining trace levels of nitrite
in the presence of large amounts of nitrate.
CElixirOA provides simple, reliable and rapid separations covering a wide range of applications. With good
linearity and reproducibility below 0.5% RSD for migration times (click here to view chart) CElixirOA is a
valuable alternative to traditional techniques such as Ion Chromatography.