Add 1 or 2 drops or 50 mg of unknown to 5 mL of water. If necessary, 1 or 2 drops of conc. HCl may be added to dissolve the amine. Add 0.5 mL of amine solution to 3 mL of the nickel chloride and 5-nitrosalicylaldehyde reagent. To make reagent: to 15 mL of triethanolamine is added a solution of 0.5 g of 5-nitrosalicylaldehyde dissolved in 25 mL of water. Then 0.5 g of nickel chloride hexahydrate dissolved in 10 mL of water is added, and the total volume of the solution is brought to 100 mL.
1o aliphatic amines- immediate copious precipitate is a positive test.
1o aromatic amines- copious precipitate (after 2 - 3 minutes) is a positive test.
Extremely sensitive reagent and could give erroneous results.
Hydroxyl amines and hydrazines give positive test.
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