Hydrazoic acid was originally prepared by the reaction of aqueous hydrazine with nitrous acid. Other oxidizing agents, such as hydrogen peroxide, nitrosyl chloride, trichloramine or nitric acid, can also be used. In its properties hydrazoic acid shows some analogy to the halogen acids, since it forms poorly soluble (in water) lead, silver and mercury(I) salts. The metallic salts all crystallize in the anhydrous form and decompose on heating, leaving a residue of the pure metal. It is a weak acid (p"K" = 4.75.) Its heavy metal salts are explosive and readily interact with the alkyl iodides. Azides of heavier alkali metals (excluding
Fulvic acid only method that the California departments of agriculture will accept when registering a product. California does not recognize fulvic acid as separate substance from humic acid and requires that all label registrations list the content as humic acid only. Until 2017, Oregon also required using this method but has recently switched to the Lamar Method of fulvic acid quantification and now allows the label registration of fulvic acid as a substance apart from humic acid. The Verploegh and Brandvold method (V&B) quantifies both humic and fulvic acid and is a quick, cost effective, and easy test to perform. It does