In vitro monitoring of nanogram levels of puerarin in human urine using flow injection chemiluminescence

A rapid and sensitive chemiluminescence (CL) determination of puerarin with the flow injection technique was presented. It was found that puerarin could enhance the CL generated from luminol–KIO4 system significantly. The increment of CL intensity was linear over the concentration of puerarin ranging from 0.3 to 100.0 ng mL−1 (r2=0.9963), offering a detection limit as low as 0.1 ng mL−1 (3σ). At a flow rate of 2.0 mL min−1, one analysis cycle, including sampling and washing, could be accomplished in 20 s with a relative standard deviation of less than 5.0%. The experimental results demonstrated that the excretive amounts of puerarin reached its maximum in 3 h after taking 250 mL green drink containing 275 mg puerarin, and the puerarin excretive ratio during 24 h was 9.70% in the body of volunteers.