Sodium salt was one of the substances revealed by USS Enterprise-D spectral analysis to comprise the sentient inorganic microbrain lifeform of Velara III. According to Worf, this compound meant that the microbrain was a conductor. (TNG: "Home Soil")
The use of the combined term "sodium salt" is a bit unusual. This most likely means that the salt is not sodium chloride (table salt), but another sodium based salt.