If suitable adsorbents can be developed, solid-phase extraction using antibodies to selected analytes is potentially much more selective than liquid-liquid or solid-phase extraction. This preliminary study uses antisera to morphine immobilized on controlled-pore glass to investigate the feasibility of developing a selective extraction procedure. Columns are washed with 0.3% HCl and primed with phosphate-buffered saline. Phosphate-buffered saline of different pH and with different organic modifiers was investigated as elution solvent. The results indicate that morphine could be extracted from aqueous solution using an immune-extraction column and desorbed in a 1-mL fraction using 60% ethanol in phosphate-buffered saline of pH 2