Which compound may be detected by observing its orange-red fluorescence in acid solution?

Which compound may be detected by observing its orange-red fluorescence in acid solution?

• A. Porphobilinogen
• B. Uroporphyrinogen
• C. Aminolevulinic acid
• D. Coproporphyrin

Answer: (D)

Orange-red fluorescence in acid solution is a telltale signal of certain porphyrin compounds. Coproporphyrin is a porphyrin derivative that emits a strong orange-red glow when dissolved in acidic conditions, which is why this property is used for its detection in clinical tests. The acid environment enhances the porphyrin’s fluorescence, making it visible with simple fluorescence observation. The other listed substances do not produce this same orange-red signal under the same acid conditions; porphobilinogen and uroporphyrinogen either lack strong fluorescence or fluoresce differently, and aminolevulinic acid is not known for orange-red fluorescence in acid.

Orange-red fluorescence in acid solution is a telltale signal of certain porphyrin compounds. Coproporphyrin is a porphyrin derivative that emits a strong orange-red glow when dissolved in acidic conditions, which is why this property is used for its detection in clinical tests. The acid environment enhances the porphyrin’s fluorescence, making it visible with simple fluorescence observation.

The other listed substances do not produce this same orange-red signal under the same acid conditions; porphobilinogen and uroporphyrinogen either lack strong fluorescence or fluoresce differently, and aminolevulinic acid is not known for orange-red fluorescence in acid.