Studies on the Use of XAD-2 Resin for Detection of Abused Drugs in Urine

Abstract

Abstract We describe a procedure for extracting weakly acidic, neutral, and basic drugs from urine by using a column of XAD-2 resin. Adsorption of drugs from 20 ml of urine buffered at pH 8.5 ± 0.5 at a controlled flow rate of 2.5 ml/min was greater than 89% for all drugs tested except aspirin. On eluting the drugs tested with acetone and methanol/chloroform, recoveries ranged from 75 to 93%. Overall recoveries of drugs from urine to a thin-layer chromatography plate were between 63 and 78%. The concentration of morphine added to normal urine that can be detected 99% of the time (95% confidence limits) by this method was 80 (65-100) µg/liter. We evaluated three methods for recovering morphine from morphine glucuronide added to urine, by using appropriate modifications of the XAD-2 resin extraction method. Hydrolysis of urine, hydrolysis of urine extracts adsorbed on XAD-2 resin, and hydrolysis of urine extracts from the XAD-2 resin followed by a solvent extraction gave 75%, 40%, and 10% recoveries of morphine, respectively.