Organometallic intermediates in Böttger test for glucose in urine

The reaction mechanism in organometallic chemistry is not always correctly understood or it is missing. In this communication the reaction route in the Böttger test for glucose is provided. The reagent can be bismuth subnitrate or bismuth meta-hydroxide (also called hydrated oxide of bismuth), since in alkaline medium (sodium carbonate) the nitrate ion is displaced by hydroxyl. The basic medium is essential in order to activate the glucose molecule. The reaction goes through a series of organometallic intermediates in a redox process. Finally, elemental bismuth separation occurs via one electron transfer in a bimolecular reaction. The white insoluble solid formed in situ blackens since it is covered by metallic bismuth.