Capillary electrophoresis coupled with electrochemiluminescence for determination of atomoxetine hydrochloride and the study on its interactions with three proteins.

A simple, rapid and sensitive method for the determination of atomoxetine hydrochloride (AH) by capillary electrophoresis with electrochemiluminescence detection (CE-ECL) using tris(2,2'-bipyridyl) ruthenium (II) was developed. Under optimized conditions, the determinations of AH in capsules and rat plasmas and the study on its interactions with three plasma proteins, including bovine serum albumin, cytochrome c and myoglobin were performed successfully. Relative to some previous studies, in this paper the methodologies for the determination of AH in aqueous solution and spiked plasma systems were established, respectively. By comparing the difference between the two work curves of two systems, the matrix effect in plasma samples on the determination of AH by the CE-ECL method was discussed in detail. The results indicated that the effect of the matrix in plasma samples should not be ignored even if no obvious interference was found in the electropherograms and the establishment of method validation in complex samples by the CE-ECL method was necessary.