离子色谱法测定云南普洱茶中的NO_2^-·NO_3^-和PO_4^(3-)含量

Determination of NO_2^-NO 2- 、·NO_3^- and PO_4^(3-) Contents in Yunnan Pu’er Tea by Ion Chromatography

[目的]研究几种云南普洱茶中NO2-、NO3-、PO43-3种阴离子的色谱分析条件。[方法]选取云南省临沧、勐海、普洱3个主要茶区的茶样为研究对象,以浓度0.063 6 g/L Na2CO3与1.008 0 g/L NaHCO3的混合液为流动相,1 ml/min的流动相流速,对样品进行色谱分析。[结果]该方法回归方程的线性相关系数均达到0.999 9以上,NO2-、NO3-、PO43-3种阴离子的检出限均在0.01～0.03 mg/L。[结论]该方法测定茶叶样品中的阴离子简便快速,所得结果令人满意。

[Objective]To study the chromatographic analysis conditions of three anions NO 2-,NO 3-and PO34-in several varieties of Yunnan Pu’er tea.[Method]With the tea sampled from Lincang,Menghai and Pu’er of Yunnan Province as the study objects,they were chromatographically analyzed with 0.063 6 g/L Na2CO3 and 1.008 0 g/L NaHCO3 as the gradient eluant at a flow rate of 1 ml/min.[Result]The correlation coefficients of linear regression equations were all above 0.999 9,and the detection limits of the three anions were in the range of 0.01-0.03 mg/L.[Conclusion]The method was simple and fast with satisfactory results in detecting the anions in tea samples.