Liquid chromatographic determination of cyclosporin A using aryl oxalate chemiluminescence detection

A new liquid chromatographic method based on aryl oxalate chemiluminescence detection for the determination of immunosuppressing drugs like cyclosporin A is described. Cyclosporin A was separated using a Zorbax C8 analytical column with 0.1 M hydrogen peroxide in methanol-water (95 + 5) as eluent, and could be determined from 5.0 × 10−9 to 2.0 × 10−2 M (signal-to-noise ratio = 3, 500 μl injection of serum sample) by bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate (TDPO) and sulphorhodamine 101 chemiluminescence detection. The relative standard deviation was 5.1% at 1.0 × 10−6 M cyclosporin A (n = 6). The recovery was 89.1% with 1.0 × 10−6 M serum sample (n = 6). Serum and whole blood samples were measured by liquid chromatography with ultraviolet detection and and fluorescence polarization immunoassay, and correlation coefficients of 0.97 (n = 20) and 0.92 (n = 16), respectively, were obtained.