Mass screening and confirmation of codeine and morphine in urine by radioimmunoassay-GLC.

A rapid, sensitive, and specific procedure is described for the mass screening and confirmation of codeine and morphine in urine specimens. The method is sensitive to 0.5-mug/ml levels of both opiates in free and/or conjugate forms. The raw urine is screened directly by radiommunoassay, which is reactive to both free and glucuronide forms of codeine and morphine. Specimens that are screened positive are confirmed by GLC using a flame-ionization detector. The opiates are analyzed as their acetyl derivat-ves on two different columns, OV-25 and Poly-A 103. This multiple approach eliminates false positives caused by interfering substances or structurally similar compounds present in the urine.