Determination of Eight Different Biogenic Amines in Pu'er Tea by HPLC

Abstract

Determination of the biogenic amines in Pu’er tea is very important for its production and quality control. An analytical method for the quantification of biogenic amines in Pu’er tea using high performance liquid chromatography (HPLC) has been developed. Eight biogenic amines (Methylamine, Ethylamine, Cadaverine, Putrescine, Tryptamine, Histamine, Tyramine, Spermidine) in 106 Pu’er ripe tea, 60 raw tea and 41 sun dried green tea and their corresponding boiled tea liquor were analyzed by this method. The tea sample solutions were pretreated with homogenization, liquid-liquid extraction and centrifugal ultrafiltration. Dansyl chloride (DnsIC) was employed as the pre-column derivatization reagent, and subsequent separation of eight biogenic amines was conducted on a Waters-Atlantisd C18 (PR-18e ID 5 μm) column with a mixture of acetonitrile and water (65:35, V/V) as the mobile phase. The analytes were monitored using a fluorescence detector with absorbance detection between 230 nm and 280 nm. The method was consistent (RSD 0.99). The recoveries from all kinds of Pu’er tea satisfactorily ranged from 94% to 102% and the lowest quantification limit was estimated to be 0.55-1.03μg /L. Our results showed that among 207 kinds of tea tested, Pu’er ripe tea contains the most kinds of and the highest content of the biogenic amines, followed by Pu’er sun dried tea, and Pu’er raw tea contains the least. The method should be helpful for the quantification of biogenic amines in the tea product and the tea quality control.