sensitive method for simultaneous determination of four macrolides by CE with electrochemiluminescence detection and its applications in human urine and tablets

A sensitive method for simultaneous determination of azithromycin (AZI), acetylspiramycin (ACE), erythromycin (ERY), and josamycin (JOS) was developed by CE coupled with electrochemiluminescence detection with Ru(bpy)₃ ²⁺. The parameters related to separation and detection were investigated in detail. The four macrolides were well separated and detected within 6 min under the optimized conditions. The LOD (S/N=3) of AZI, ACE, ERY, and JOS were 1.2x10⁻⁹, 7.1x10⁻⁹, 3.9x10⁻⁸ and 9.5x10⁻⁸ mol/L, respectively. The LOQ (S/N=10) of AZI, ACE, ERY, and JOS in human urine were 8.2x10⁻⁸, 2.5x10⁻⁷, 8.9x10⁻⁷ and 1.2x10⁻⁶ mol/L, respectively. The recoveries of the four macrolides in human urine and pharmaceutical tablet samples were 85.0-104.0% at different concentration levels.