Very sensitive and specific determination of sufentanil in human serum applying liquid chromatography–two stage mass spectrometry

Sufentanil is the most potent synthetic opioid currently in use. Extremely low serum concentrations have to be determined for therapeutic drug monitoring and to support brain death diagnosis by excluding opioid induced coma. The described method utilizes a HPLC–MS–MS system with an electrospray ion source and an ion-trap mass spectrometer. The serum samples were extracted under basic conditions with toluene–2-propanol (10:1, v/v). Chromatographic separation was achieved on a RP-18 70×2 mm column with a 0.02% trifluoroacetic acid in a water–acetonitrile gradient as mobile phase. The limits of detection and quantification are 3 and 10 pg/ml, respectively. At the limit of quantification, the intra-day relative standard deviation of the assay is 12.6% and the inter-day relative standard deviation is 14%.