osmium tetroxide

American  

noun

Chemistry.

1. a crystalline or amorphous, colorless, poisonous compound, OsO 4 , soluble in water, alcohol, and ether: used for microscopic staining, in photography, and as a catalyst in organic synthesis.

---

osmium tetroxide British  

noun

1. a yellowish poisonous water-soluble crystalline substance with a penetrating odour, used as a reagent and catalyst in organic synthesis. Formula: OsO 4

---

Etymology

Origin of osmium tetroxide

First recorded in 1875–80

Example Sentences

Police allege that Phillips possessed osmium tetroxide for a dangerous purpose.

From Washington Post

Police say Christopher B. Phillips, 42, possessed a chemical called osmium tetroxide for a dangerous purpose.

From Washington Post

For secondary fixation, we used 2% osmium tetroxide in 1.25% sodium bicarbonate for 2–3 h at room temperature.

From Nature

After a secondary fixation in 1% osmium tetroxide, 1.5% potassium ferricyanide, samples were dehydrated through a graded ethanol series, and embedded in situ in an epon analogue resin.

From Nature