Combustion ion chromatography introduces a much smaller amount of sample gases into a relatively larger volume of water, resulting in low concentrations of analytes at injection. In addition, for sulfate analysis, addition of hydrogen peroxide is necessary to oxidize different sulfur species to sulfate. However, peroxide may interfere with the fluoride peak.
Several solutions are available to overcome these problems:
- Increase of initial sample size
- Increase of injection volume applied to IC
- Sample preconcentration, which can be a better option