Fehlingreaktioner
Fehlingreaktioner are qualitative tests used to detect the presence of reducing sugars and aldehydes. Developed by Hermann von Fehling in 1849, these reactions rely on the reducing properties of these compounds. The Fehling's solution is typically prepared as two separate solutions, Fehling's solution A (an aqueous solution of copper(II) sulfate) and Fehling's solution B (an alkaline solution of potassium sodium tartrate). When these two solutions are mixed, they form a complex of copper(II) ions in an alkaline environment.
When a sample containing a reducing sugar or aldehyde is added to the Fehling's solution and heated,