摘要：Efficient and simple extraction method for cocaine in human urine was developed by the addition of tri-n-propylamine to the urine sample and by the use of GC/MS for the determination. The quantitative extraction of trace amounts of cocaine in the human urine is very hard with conventional organic solvents. However, in the present study, tri-n-propylamine was found to extremely raise the extractability of trace amounts of cocaine. The recommended procedure is as follows : to 20 ml urine containing less than 1.2 μg of cocaine in 50 ml separatory funnel, 1 ml of 15% sodium carbonate aqueous solution, 1 ml of aqueous solution saturated with tri-n-propylamine, and 10 ml of dichloromethane are added. It is shaken for 3 min and centrifuged for further 3 min at 3500 rpm in a 50 ml centrifuge tube. To a part (5 ml) of the resulting dichloromethane phase, 1 ml of n-tricosane dichloromethane solution (537 ng/ml) is added as an internal standard. The solution is then concentrated on a water bath to 0.2 ml at 60±5°C and the cocaine is determined by GC/MS. The extraction efficiency was 97% at least of 20 ng of cocaine·HCl tested. In human urine containing less than 1.2 μg of cocaine, the extraction efficiency was always higher in the presence of tri-n-propylamine than in the absence of the base.
