Determination of troglitazone stereoisomers in rat plasma using semi-micro HPLC with electrochemical detection

A highly sensitive determination method for troglitazone stereoisomers was developed by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The oxidation behavior of troglitazone was investigated for the application of ECD by measuring the cyclic voltammogram. The separation was performed on a semi-micro chiral column (Chiralcel OJ-RH) using a mobile phase consisting of methanol-acetic acid (1000:1, v/v) containing 50mM LiClO4 at a flow rate of 20 microl/min. The peak areas of the stereoisomers separated from 0.1 to 50 ng/ml of troglitazone had good linearity with correlation coefficients of >0.999, and had similar response. The limit of detection was 1.3 fmol (signal-to-noise ratio of 3). This method was applied to the determination of troglitazone stereoisomers in rat plasma. The levels of troglitazone stereoisomers in rat plasma could be monitored until 24h after the oral administration.