Determination of picogram-levels of acetylspiramycin in human urine and serum by flow injection chemiluminescence

A sensitive chemiluminescence method for the determination of acetylspiramycin is presented. It is based on the greatly enhancive effect of acetylspiramycin on the chemiluminescence reaction between luminol and hydrogen peroxide in the flow system. The increase in chemiluminescence intensity was linearly proportional to the acetylspiramycin concentration in the range from 10 pg . mL(-1) to 2.0 ng . mL(-1) (r(2) = 0.9979). The detection limit was 3 pg . mL(-1) ( 3sigma). At a flow rate of 2.0 mL . min(-1), the process of determination, including sampling and washing, could be performed in 0.5 min, and the relative standard deviations of seven replicates are less than 5.0%. The proposed method was applied successfully to the determination of acetylspiramycin in pharmaceutical preparations, human urine and serum without pre-treatment. It was found that the excretive ratio of acetylspiramycin reached its maximum 2.0 hours after having been administered orally, and the excretive ratio in 12.0 hours was 8.4parts per thousand.