Hytritium

Hytritium is the only compound able to neutralize tricyanate contamination. It is highly unstable, expensive to produce, and too dangerous to deliver by transporter, so many traders stopped buying and selling it. Fortunately, Zibalian trader Kivas Fajo was in possession of a quantity of the substance aboard his ship Jovis when the USS Enterprise-D required it to clean the water table of the planet Beta Agni II in 2366.

In reality, Fajo had actually created the contamination, using the transfer of the substance to kidnap Data in order to add him to his collection of rare treasures, destroying the shuttlecraft Data had used and putting enough of the material from which the android was created to make Enterprise believe he had perished in the explosion. Unfortunately for Fajo, the hytritium neutralized the tricyanate so quickly that it became clear that the water had been poisoned, leaving the Enterprise crew quite suspicious of the trader who happened to have exactly the right amount of the very rare compound just when it was needed most - after discovering just a few of the objects he possessed, the crew deduced that Data had been abducted and his death faked, at which point they tracked the Jovis, rescued Data, and arrested Fajo. (TNG: "The Most Toys")