Analysis of opiates in urine using microextraction by packed sorbent and gas Chromatography- Tandem mass spectrometry

•Rapid extraction process using a small sample volume (250 µL);•First developed method to quantify tramadol, codeine, morphine, 6-acetylcodeine, 6-monoacetylmorphine and fentanyl in urine using microextraction by packed sorbent and GC/MS-MS;•The method was fully validated, and good limits were obtained (1–10 ng/mL)