HPLC-MS/MS Determination of Residual Amounts of 28 Abused Drugs in Human Urine

A method of HPLC-MS/MS for the determination of 28 abused drugs, such as opioids, amphetamines and cocaines, in human urine was proposed. The sample was extracted with ethyl acetate, after centrifugation, the supernatant was taken and evaporated to dryness by N2-blowing at 40 ℃. The residue was taken up with 1.0 mL of a mixture of methanol and water (30+70) and analyzed by HPLC-MS/MS. Linear relationships between values of peak area and mass fraction of 28 abused drugs were kept in the same range of 2.0-200 μg·kg-1, with detection limits (3S/N) in the range of 1.0-2.0 μg·kg-1. Recovery and precision of the method were tested by addition of mixed abused drugs standards at 3 concentration levels of 5,10,50 μg·kg-1, giving values of recovery in the range of 61.0%-117% with RSD′s (n=6) in the range of 3.0%-14%.