Quantitative determination of amitriptyline in blood.

An assay was developed and standardized for amitriptyline and its hydroxylated tertiary amine metabolites in blood and other biological tissues. This method is capable of determining 5--15 ng of these compounds/ml and is based on reacting the drug as base with 9-bromomethylacridine to form a quaternary product which, on photolysis, yields fluorescence in a stoichiometric fashion. The precision of the method is usually around +/-5%.