论文部分内容阅读
目的使用亲水性C_(18)硅胶反相色谱柱同时分离测定红茶中11种有机酸。方法经ACCHROM XAqua C_(18)柱(4.6 mm×150 mm,5μm)分离,以0.1%三氟乙酸-乙腈为流动相梯度洗脱,流速1.0 mL/min,柱温25℃,检测波长214 nm。结果 11种有机酸在13 min内实现基线分离,平均回收率为92.07%~101.64%,相对标准偏差为0.54%~1.93%,各有机酸线性相关系数r>0.9986。对不同产地6个红茶样品进行测定,云南凤庆红茶样品有机酸含量最高(668.62 mg/L),锡兰红茶样品含量最低(386.67 mg/L,);红茶有机酸以草酸为主,含量范围在119.67~193.18 mg/L;乳酸(0~193.43 mg/L)和乙酸(36.62~193.98 mg/L,)含量在不同产地红茶样品中相对差异较大。结论本实验建立了一种较准确、高效、简便的茶叶有机酸检测技术与方法,运用此方法测定不同产地红茶有机酸含量并分析与比较不同红茶的有机酸组分差异性,并为红茶品质风味的审评及加工工艺改良提供一定数据参考。
Objective To separate 11 kinds of organic acids in black tea by using hydrophilic C_ (18) silica gel reverse phase column. The method was separated by ACCHROM XAqua C_ (18) column (4.6 mm × 150 mm, 5 μm) and eluted with 0.1% trifluoroacetic acid-acetonitrile as mobile phase with a flow rate of 1.0 mL / min and a column temperature of 25 ° C. The detection wavelength was 214 nm . Results The results showed that the average recoveries of 11 organic acids were 92.07% ~ 101.64% within 13 min with the relative standard deviations of 0.54% ~ 1.93%. The linear correlation coefficients of organic acids were> 0.9986. The results showed that the content of organic acid in Fenghong black tea samples was the highest (668.62 mg / L) and that of Ceylon black tea samples was the lowest (386.67 mg / L). The main organic acids in black tea were oxalic acid, (119.67-193.18 mg / L); the contents of lactic acid (0-193.43 mg / L) and acetic acid (36.62-193.98 mg / L) were relatively different among the black tea samples from different areas. Conclusion This experiment established a more accurate, efficient and simple tea organic acid detection techniques and methods used to determine the organic acid content of black tea in different areas and analysis and comparison of different black tea organic acid composition differences, and for the black tea quality Flavor review and processing technology to provide some data to improve reference.