Two definitions of salinity have been in use since the early part of the present century (Knudsen 1901, Forch et al. 1902). According to the procedural definition, salinity is the amount (in grams) of dissolved solid material in a kilogram of seawater after all the bromine has been replaced by an equivalent quantity of chlorine, after all the carbonate has been converted to oxide, and after all of the organic matter has been destroyed....
Wooster, Warren S., Arthur J. Lee, and Gunter Dietrich. 1969. "Redefinition of salinity." Journal of Marine Research 27, (3). https://elischolar.library.yale.edu/journal_of_marine_research/1167