An HPLC-fluorescence detection method for simultaneous determination of N-benzylpiperazine (BZP) and 1-(3-trifluoromethylphenyl)piperazine (TFMPP) labeled with 4-(4,5-diphenyl-1 H-imidazol-2-yl)benzoyl chloride (DIB-Cl) was described. DIB-BZP and -TFMPP were well separated within 13 min without interference of peaks from plasma components. The lower detection limits of BZP and TFMPP at a signal-to-noise ratio of 3 were 0.9 and 4.6 ng/mL, respectively. Precisions of the proposed method for intra- and inter-day assays were less than 4.8 and 9.1% as %RSD (n =5). Furthermore, the method could be successfully applied to monitor both compounds in plasma after their sole or co-administration to rats (each dose, 2 mg/kg). Clearance of TFMPP was significantly different under the conditions (P=0.047).
Copyright © 2011 John Wiley & Sons, Ltd.