[kapital]

Is it possbile to separate sodium and chloride ions, if we inject sodium chloride solution in HPLC apparatus?

[Arkcon]

If you Google for ion chromatography, you will find something similar to what you suggest.  I did try to Google for a demonstration chromatogram of someone who has separated mixed anions and cations, and generated a IC chromatogram identifying such peaks, as a demonstration, but I'm not finding it.  Anyway, yes, mixed anions and cations are separable on an ion chromatograph.  They are typically detected with a conductivity detector, and such a system needs an ion suppressor post-column, but before the detector, because the eluent is usually an ionic solution itself.  Give the terms a Google and see if you can find what you're looking for.