Rapid, efficient procedure for extraction of drugs for toxicological analysis.

In most cases isolation of drugs from biological samples taken from drug overdose cases has been performed by solvent extraction, for example at pH 9.5 (1), pH 7 (2), or without pH adjustments (3). These techniques do not efficiently extract both strong bases (such as amphetamine) and strong acids (such as acetylsalicylic acid). A two-step extraction of the biological sample at different pH values (4/5 ) increases efficiency but is longer. A single-step isolation based on the extraction of the amines as ion pairs with bromcresol purple at pH 6 has recently been described (6). We wished to develop a fast, efficient procedure for isolating drugs for subsequent analysis by gas chromatography-.mass spectrometry by using a column chromatographic extraction technique involving extraction of the acids in a nonionized form and the amines as ion pairs.