GLC/TLC analysis of codeine and morphine in urine via derivatization techniques.

A procedure has been developed for the TLC and GLC analysis of codeine and morphine derivatives in urine in cases where there is too much interference for TLC analysis as free drugs. Urine is hydrolyzed, then split into two fractions. One fraction is extracted with a polar solvent, concentrated, and acetylated. An aliquot is injected in a 3% OV-17 column and the rest is spotted on a plate developed in hexane:chloroform:diethylamine (50:30:6). The other fraction is ethylated (converting morphine to ethylmorphine), extracted with a nonpolar solvent, concentrated, acetylated, concentrated, and then spotted on a plate developed in hexane:n-butanol:acetonitrile:diethylamine (80:5:5:10). Codeine and morphine can be detected without interference at concentrations as low as 0.3 micrograms/mL.