Look for solubility data of H2S(g) in NaCl-solutions, e. g. here Article Solubility of hydrogen sulfide in pure water and in NaCl sol...

Adopting a Henry constant at the given temperature you can derive Pitzer coefficients for the interaction lambda (Na, HS) setting lambda (Cl-HS) = zero.

Other values can be found here (german report): https://www.grs.de/content/grs-195

Cheers

Helge

Thank You for literature sources and valuable tips. I'll try to derive the parameters from solubility data.

However, I'm surprised that such parameters are not given "on a silver platter" like for example in: Kim i Frederick Jr, „Evaluation of Pitzer ion interaction parameters of aqueous electrolytes at 25. degree. C. 1. Single salt parameters”.

Best regards,

Marcin Stec

Also you can see publications of Walter Furst, Xavier Ball and Henri Renon