A method for detection in urine of narcotic drugs, quinine, barbiturates, amphetamines, and some tranquilizers appears to be applicable to a wide range of diagnostic problems and epidemiological studies. The drugs are first absorbed on ion-exchange paper and then eluted with a series of buffer-solvent systems. An aliquot of the solvent phase is concentrated and chromatographed. A series of detection sprays have been developed to provide both sensitive detection and confirmation of positive results.
Dole VP, Kim WK, Eglitis I. Detection of Narcotic Drugs, Tranquilizers, Amphetamines, and Barbiturates in Urine. JAMA. 1966;198(4):349-352. doi:10.1001/jama.1966.03110170061017