碧螺春茶叶中无机阴离子的离子色谱测定法

目的建立能够同时检测绿茶中几种无机阴离子的方法,测定碧螺春中无机阴离子的含量。方法将20份碧螺春和一级炒青分别浸泡于70℃左右的去离子水中,经过超声和脱色处理后用离子色谱仪分析。结果以氟化物指标为例,相对标准偏差(RSD)范围在4%以内,加标回收率范围在90%～105%;F-含量为1.0～3.0 mg/L,Cl-含量为1.0～4.00mg/L,NO3-含量为0.5～1.50 mg/L,SO42-含量为0.5～2.00 mg/L。结论离子色谱法可同时检测茶叶中4种无机阴离子。该法准确性高,精度高,稳定性好。

Determination of Inorganic Anions in Biluochun Tea by Ion chromatography

Objective]To establish the method for simultaneous determination of several kinds of inorganic anions in green tea,to determine the inorganic anions levels in Biluochun Tea.Methods]Twenty samples of Biluochun and a roasted sample were soaked in deionized water about 70 ℃,then treated by ultrasound and decolorization,and analyzed by ion chromatography.Results]For indicator of fluoride,the relative standard deviation（RSD） was within the range of 4%;recoveries were in the range 90%～105%;F-was 1.0～3.0 mg/L;Cl- 1.0～ 4.00 mg/L;NO3- 0.5～ 1.50 mg/L;SO42-0.5～2.00 mg/L.Conclusion]Ion chromatography can simultaneously determine 4 kinds of inorganic anions with characteristics of high accuracy,high precision and good stability.