茶饮料中微量色素物质的HPLC分析方法研究

以含乙腈的流动相作为洗脱剂,对茶饮料中微量色素物质的HPLC分析方法进行了研究。结果显示,在色谱柱长为15cm、柱温为35℃、总流量为1ml、检测波长450nm条件下,最佳的洗脱参数为:①以3/0.5/96.5(v/v/v)的乙腈、乙酸和水的混合液为流动相A,以75/15/10(v/v/v)的乙腈、甲醇和氯仿混合液为B相;②梯度洗脱,即前20min内B相由80%上升到100%,并保持15min。在该条件下新黄质、紫黄质、叶黄素、叶绿素b、叶绿素a、脱镁叶绿素b、β-胡萝卜素和脱镁叶绿素a等色素物质均可获得基线分离。同时研究还显示,该方法重复性较好,检测限低,可满足绿茶饮料中微量色素物质的分析。

Study on HPLC Method for the Analysis of Trace Pigments in Ready-to-drink Tea

Study on HPLC method for analyzing of trace pigments in ready-to-drink tea was conducted by using different eluants with acetonitrile as mobile phase. Result showed that gradient elution was suitable for analyzing by using acetonitrile/acetic acid/water in ratio of 3/0.5/96.5(v/v/v) as mobile phase A, and using acetonitrile /methanol /chloroform in ratio of 75/15/10(v/v/v) as mobile phase B. The optimized elution time program could be described that phase B increased gradiently from 80% to 100% in early 20 minutes, then remained 100% for 15 minutes. The main pigments, i.e. neoxanthin, violaxanthin, lutein, chlorophyll b, chlorophyll a, phaeophytin b, β-Carotene and phaeophytin a, could be separated upto baseline under that condition. Verification test showed that the optimized HPLC method with good repeatability and low detection limits was suitable for measurement of trace pigments in ready-to-drink tea.