Ultrasensitive determination for picomolar-level midecamycin in human serum by flow injection chemiluminescence using luminol-BSA system

摘要

An ultrasensitive method for determining picomolar midecamycin (MID) by flow injection (FI) chemiluminescence (CL) was first described based on the inhibitory effect of MID on luminol-BSA reaction. It was found that the CL intensity decrements were linear with the logarithm of MID concentrations in the range of 1.0-5000 pmol · l~(-1) with a detection limit as low as 0.3 pmol · l~(-1) (3σ). The relative standard deviation of seven repetitive measurements for 10 pmol · l~(-1) MID was 3.0%. At a flow rate of 2.0 ml · min~(-1), the whole analysis procedure including sampling and washing could be finished in 30 s, offering the sample efficiency of 120 h~(-1). This proposed method was successfully applied to determine MID in human serum samples with the recoveries from 96.0 to 110.0%. The CL mechanism of luminol-BSA-MID reaction was also given.