Abstract: Objective Disk solid phase extraction(SPE)was assessed for tramadol hydrochloride from serum. Methods The SPE was performed with SPEC C18 AR/MP3 Disk SPE cartridge, offering hydrophobic C18 and strong cation ionic exchange interactions for the analytes, before being added into extraction column, 1mL serum was diluted by 2 mL 0.1 mol/L phosphate buffer solution (pH 6) and the eluent was ethyl acetate containing 2% ammonia. Then SKF525 was added as internal standard into samples, which would be extracted simultaneously with analyte,quantitatively, determined by GC/MS/SIM. Results The extraction recovery of tramadol hydrochloride was 98.9%, 92.5% and 84.8% for serum samples with corresponding amounts of standard addition of 0.1 μg/mL, 0.2 μg/mL and 0.5 μg/mL. And RSD measured 5 times was 3.2%, 8.7% and 10.9% respectively. The linear range varied from 0.1 μg/mL to 4 μg/mL. The multinomial regression correlation coefficient (r2) equaled 0.9939, and the detection limit was 21 ng/mL. After the same extraction column was continuously used for 5 times, there was no jam, pollution and decline of recovery and RSD. Conclusion This method is suitable for forensic toxicological analysis.

Key words: tramadol hydrochloride, disk SPE, GC/MS/SIM, forensic toxicological analysis