Fluorometric determination of isonicotinic acid hydrazide in serum.

Abstract

Abstract A protein-free filtrate of serum was treated with salicylaldehyde to give a hydrazone of INH. Excess salicylaldehyde was removed with bisulfite. The hydrazone in the presence of reducing agents gave an isobutanol-soluble, highly fluorescent compound of unknown structure. The method developed will measure as little as 0.01 μg INH per milliliter of serum.