1 材料与方法
1.1 试验材料与试剂
1.2 试验仪器
1.3 试验方法
1.3.1 色谱条件
表1 高效液相色谱流动相梯度程序 |
| 时间/min | 溶剂A/% | 溶剂B/% |
|---|---|---|
| 0 | 5.0 | 95.0 |
| 14 | 14.5 | 85.5 |
| 15 | 15.0 | 85.0 |
| 25 | 20.0 | 80.0 |
| 35 | 25.0 | 75.0 |
| 45 | 35.0 | 65.0 |
| 50 | 90.0 | 10.0 |
1.3.2 样品和标准溶液的制备
1.3.3 线性关系检验
1.3.4 精密度
1.3.5 稳定性
1.3.6 重复性
1.3.7 加样回收率
1.3.8 化合物含量
1.3.9 颜色变化与pH
1.4 数据处理
2 结果与分析
2.1 方法学检验
2.1.1 线性关系
表2 7种成分的线性关系 |
| 成分 | 线性回归方程 | R 2 | 线性范围/(mg/mL) |
|---|---|---|---|
| GA | y=495.38x + 26.922 | 1.000 0 | 1.994 1~12.001 0 |
| C | y=280.87x + 11.782 | 0.999 7 | 1.980 0~12.073 8 |
| EC | y=199.04x + 18.897 | 1.000 0 | 1.977 8~11.986 1 |
| EGCG | y=1 388.20x + 5.412 | 0.997 6 | 2.000 2~11.908 2 |
| GCG | y=194.39x-18.644 | 0.999 9 | 1.960 3~11.941 8 |
| ECG | y=1 145.30x + 3.582 | 0.999 6 | 2.073 8~12.062 1 |
| 咖啡因 | y=1 733.30x + 229.480 | 0.999 5 | 1.891 7~11.996 7 |
2.1.2 精密度
2.1.3 稳定性
2.1.4 重复性
2.1.5 加样回收率
表3 普洱茶中GA、C、EC、EGCG、GCG、ECG和咖啡因的回收率 |
| 成分 | 原有量/mg | 加入量/mg | 测得量/mg | 回收率/% | 平均回收率/% | RSD/% |
|---|---|---|---|---|---|---|
| GA | 11.148 5 | 10.560 0 | 21.759 0 | 100.45 | 101.07 | 0.97 |
| 11.091 3 | 10.560 0 | 21.743 3 | 100.83 | |||
| 11.073 6 | 10.560 0 | 21.738 2 | 100.94 | |||
| 11.011 7 | 10.560 0 | 21.745 1 | 101.57 | |||
| 10.929 2 | 10.560 0 | 21.786 5 | 102.72 | |||
| 11.237 0 | 10.560 0 | 21.787 2 | 99.91 | |||
| C | 13.111 7 | 13.166 0 | 26.404 6 | 100.97 | 100.96 | 0.09 |
| 13.112 4 | 13.166 0 | 26.408 1 | 100.99 | |||
| 13.134 4 | 13.166 0 | 26.415 2 | 100.87 | |||
| 13.168 1 | 13.166 0 | 26.448 5 | 100.86 | |||
| 13.171 1 | 13.166 0 | 26.458 9 | 100.92 | |||
| 13.148 1 | 13.166 0 | 26.461 5 | 101.12 | |||
| EC | 11.419 5 | 11.312 0 | 22.985 6 | 102.23 | 101.89 | 0.65 |
| 11.418 5 | 11.312 0 | 22.989 0 | 102.26 | |||
| 11.465 4 | 11.312 0 | 22.990 8 | 101.86 | |||
| 11.460 9 | 11.312 0 | 23.009 4 | 102.06 | |||
| 11.453 5 | 11.312 0 | 23.033 8 | 102.34 | |||
| 11.477 3 | 11.312 0 | 22.857 3 | 100.59 | |||
| EGCG | 10.181 2 | 10.160 0 | 20.496 5 | 101.53 | 101.27 | 0.69 |
| 10.184 4 | 10.160 0 | 20.508 7 | 101.61 | |||
| 10.221 2 | 10.160 0 | 20.527 7 | 101.43 | |||
| 10.216 4 | 10.160 0 | 20.537 5 | 101.58 | |||
| 10.224 2 | 10.160 0 | 20.547 7 | 101.60 | |||
| 10.246 0 | 10.160 0 | 20.391 3 | 99.86 | |||
| GCG | 12.275 1 | 12.366 0 | 24.689 1 | 100.39 | 99.43 | 1.99 |
| 12.254 2 | 12.366 0 | 24.771 3 | 101.23 | |||
| 12.312 9 | 12.366 0 | 24.152 0 | 95.72 | |||
| 12.306 7 | 12.366 0 | 24.698 9 | 100.21 | |||
| 12.300 5 | 12.366 0 | 24.700 0 | 100.27 | |||
| 12.334 5 | 12.366 0 | 24.546 8 | 98.75 | |||
| ECG | 13.230 4 | 13.290 0 | 26.683 6 | 101.23 | 100.96 | 0.83 |
| 13.237 2 | 13.290 0 | 26.700 6 | 101.31 | |||
| 13.295 1 | 13.290 0 | 26.754 0 | 101.27 | |||
| 13.297 7 | 13.290 0 | 26.754 8 | 101.26 | |||
| 13.304 0 | 13.290 0 | 26.781 1 | 101.41 | |||
| 13.328 5 | 13.290 0 | 26.519 0 | 99.25 | |||
| 咖啡因 | 12.081 6 | 12.072 0 | 24.303 9 | 101.24 | 101.35 | 0.08 |
| 12.086 7 | 12.072 0 | 24.312 6 | 101.27 | |||
| 12.093 4 | 12.072 0 | 24.336 8 | 101.42 | |||
| 12.122 7 | 12.072 0 | 24.355 2 | 101.32 | |||
| 12.124 5 | 12.072 0 | 24.366 5 | 101.40 | |||
| 12.110 4 | 12.072 0 | 24.358 3 | 101.45 |