Phosphorimetric determination of procaine,phenobarbital, cocaine,and chlorpromazine in blood serum,and cocaine and atropine in urine

A new sensitive and rapid method is proposed for the determination of procaine, cocaine, phenobarbital and chlorpromazine in blood serum, and cocaine and atropine in urine. The drug is extracted from the biological fluid using chloroform or ether, the solvent is evaporated and the resulting residue is dissolved in EPA; the EPA solution is measured phosphorimetrically. Recoveries of 100 ± 6% and relative standard deviations of 2–5% are obtained for most drugs.