Fluorimetric Determination of Morphine in Codeine

Two easy to handle, sensitive and specific fluorimetric methods for the detection and determination of morphine in codeine are described. In method A the codeine sample investigated is treated with alkaline potassium ferricyanide, whereby morphine when present will produce the fluorescent dimer pseudomorphine. In method B, the codeine sample is thermally treated with gaseous ammonia on a chromatographic plate where morphine, if present, is converted to a highly fluorescent derivative. The limits of detection were 10 ng and 20 ng for methods A and B respectively.