3-(1-Pyridinio)propane­sulfonate and 3-(benzyl­dimethyl­ammonio)propane­sulfonate monohydrate

3-(1-Pyridinio)propane­sulfonate, C₈H₁₁NO₃S, and 3-(benzyl­dimethyl­ammonio)propane­sulfonate monohydrate, C₁₂H₁₉NO₃S·H₂O, used as additives during protein refolding and crystallization, both crystallize in the monoclinic system in the P2₁/c space group, with one mol­ecule (or one set of mol­ecules) per asymmetric unit. The solvent water mol­ecule present in the second crystal structure results in the formation of a dimer through hydrogen bonds. The conformation of the propane­sulfonate moiety is similar in both structures.