Simultaneous identification and determination of biogenic amines in Pueraria lobata by ultra-high performance liquid chromatography

A method of ultra-performance liquid chromatography (UPLC) with precolumn derivatization has been established for identification and simultaneous determination of nine biogenic amines as tryptamine, phenethylamine, putrescine, cadaverine, histamine, octopamine, tyramine, spermidine and spermine in pueraria lobata. Samples were extracted with perchloric acid solution, derivitazation with dansyl chloride, added ammonia water for termination reaction and then made up to the desired volume with acetonitrile. The chromatographic separation was performed on Acquity UPLC BEH C18 column (2.1 mm x 100 mm, 1.7 mu m) using 5 mmol/L ammonium acetate and acetonitrile as mobile phase for gradient elution at the flow rate of 0.4 mL/min. Photo-diode array detector was set at wavelength of 254 nm for all of the biogenic amines. Nine biogenic amines had good linear relationships in the concentration range of 0.1-20 mu g/mL with correlation coefficients larger than 0.999. The recoveries of samples spiked at levels of 20, 50 and 100 mg/kg were 75.6-97.2% with the relative standard deviations of 0.12-5.32% (n=6). The limits of detection of the nine biogenic amines were all 10 mg/kg. The established method is simple, rapid and sensitive, which can be used for simultaneous determination of nine biogenic amines residues in Pueraria lobata and other plant medicine. By the established method, it was the first time to verify that there are biogenic amines in Pueraria lobata all over the world, which would be used to study the health care mechanism of Pueraria lobata for people.