I couldn’t find a reasonable use for it in surgery in thirty seconds of googling, but it’s not that uncommon to have to change an organic compound slightly in order to either separate it from the rest of the sample or just to detect it properly. (Apparently a cyanide compound (sodium nitroprusside) is used to help measure ketones in urine, but I don’t see how that would be used in surgery.)
I remember having to modify a pesticide we were studying with a mildly explosive compound in order to do the analysis. Not only would the damn thing explode if you shook it, but you had to make it fresh at least twice a week. It was an enormous pain in the ass.
(The name of the compound is escaping me at the moment–this was thirty years ago.)
