3,5-Dinitrosalicylic acid (DNS or DNSA, IUPAC name 2-hydroxy-3,5-dinitrobenzoic acid) is an aromatic compound that reacts with reducing sugars and other reducing molecules to form 3-amino-5-nitrosalicylic acid, which strongly absorbs light at .
Synthesis 3,5-Dinitrosalicylic acid can be prepared by the nitration of salicylic acid:
Uses
It was first introduced as a method to detect reducing substances in urine by James B. Sumner. It has since been widely used (for example) for quantifying carbohydrate levels in blood. It is mainly used in assay of alpha-amylase, however enzymatic methods are usually preferred due to DNS's lack of specificity.
Safety Although specific sensitivity information is not given, Sigma-Aldrich lists the storage class of the free acid as "other explosive materials".
Various metal salts of DNS are explosives of varying sensitivity. The copper salt explodes on rapid heating, while the lead salt is a primary explosive as impact sensitive as mercury fulminate. The barium salt is friction sensitive and both it and the dipotassium salts are impact sensitive (though not extremely so).
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