Single- and two-step extraction and thin-layer detection procedures for benzoylecgonine (cocaine metabolite) alone or in combination with a wide variety of commonly abused drugs in urine screening programs.

Three extraction procedures for the detection of benzoylecgonine (a major metabolite of cocaine) in urine are presented. Each technique has its advantages, depending on the needs of a clinical operation. Procedures I and II involve the use of ion-exchange resin-loaded paper. Procedure I has a sensitivity of 1 microng/ml and requires 20 ml of urine, and is recommended when the aim is to test for the abuse of cocaine only. Procedure II is a two-step extraction method in which a wide variety of abused drugs are extracted by the first step and the benzoylecgonine left in the aqueous buffer phase is extracted in the second step. The sensitivity for benzoylecgonine using this procedure is 2 microng/ml and it requires 20-50 ml of urine. Procedure III involves the direct extraction of benzoylecgonine using 5 ml of urine and has a sensitivity of 0.5 microng/ml.