Determination of puerarin in biological samples and its application to a pharmacokinetic study by flow-injection chemiluminescence

A simple and sensitive flow injection-chemiluminescence (FI-CL) method has been developed for the determination of puerarin, based on the fact that puerarin can greatly inhibit CL of the luminol-H2O2-haemoglobin system. The inhibition of CL intensity was linear to the logarithm of the concentration of puerarin in the range 0.08-10.0 mu g/mL (r(2) = 0.9912). The limit of detection was 0.05 mu g/mL (3 sigma) and the relative standard deviation (RSD) for 1.0 mu g/mL (n = 11) of puerarin solution was 1.4%. Coupled with solid-phase extraction (SPE) as the sample pretreatment, the determination of puerarin in biological samples and a preliminary pharmocokinetic study of puerarin in rats were performed. The recoveries for plasma and urine at three different concentrations were 89.2-110.0% and 91.4-104.8%, respectively. The pharmacokinetics of puerarin in plasma of rat coincides with the two-compartment open model. The T-1/2a, T-1/2 beta, CL/F, V-Z/F, AUC((0 - t)), MRT(0 - infinity), T-max and C-max were 0.77 +/- 0.21 h, 7.55 +/- 2.64 h, 2.43 +/- 1.02 L/kg/h, 11.40 +/- 3.45 L/kg, 56.67 +/- 10.65 mg/h/L, 5.04 +/- 2.78 h, 1.00 +/- 0.35 h and 19.70 +/- 4.67 mu g/mL, respectively. Copyright (C) 2011 John Wiley & Sons, Ltd.