Detecting the concentration of chlorpromazine
A cursory online search furnished  


Graphene paste electrode for detection of chlorpromazine by Mohammad Hadi Parvin in Electrochemistry Communications, 2011, 13, 366-369 (DOI).
A multipurpose Voltammetric Sensor for the Determination of 
Chlorpromazine in Presence of Acetaminophen, Uric Acid, 
Dopamine and Ascorbic Acid by Binesh Unnikrishnan, Pei-Chi Hsu, and Shen-Ming Chen in Int. J. Electrochem. Sci., 2012, 7, 11414-11425 (PDF).