Sensitive HPLC-fluorescence detection of morphine labeled with DIB-Cl in rat brain and blood microdialysates and its application to the preliminarily study of the pharmacokinetic interaction between morphine and diclofenac.

A sensitive high-performance liquid chromatography (HPLC)-fluorescence method for determination of morphine (Mor) in rat brain and blood microdialysates was developed using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) as a label. Mor was labeled with DIB-Cl under mild reaction conditions (at room temperature for 10 min). The separation of DIB-Mor was carried out on an octadecylsilica (ODS) column with CH(3)CN/0.1 M acetate buffer (pH 5.4) within 14 min. The detection limits of Mor in brain and blood microdialysates at a signal-to-noise ratio of 3 were 0.4 and 0.6 ng mL(-1), respectively. The proposed method was successfully applied to the preliminarily study of potential pharmacokinetic interaction between Mor and diclofenac