Table 1 The data of 20% ( v/v ) MeOH with calculation method
From: pKa determination of oxysophocarpine by reversed - phase high performance liquid chromatography
No. | pH of mobile phase | t R | Tailing factor of peak | k | pH ( i+ 1)–pH i | k ( i+ 1) – k i | (k ( i+ 1) – k i ) / (pH ( i+ 1)–pH i ) |
|---|---|---|---|---|---|---|---|
1 | 2.3 | 5.322 | 1.288 | 0.844 | - | - | - |
2 | 2.6 | 5.328 | 1.279 | 0.846 | 0.3 | 0.002 | 0.007 |
3 | 3.9 | 5.594 | 1.308 | 0.938 | 1.3 | 0.092 | 0.071 |
4 | 5.1 | 6.236 | 1.493 | 1.161 | 1.2 | 0.223 | 0.186 |
5 | 6.2 | 8.748 | 2.802 | 2.031 | 1.1 | 1.870 | 0.791 |
6 | 7.1 | 15.978 | 4.367 | 4.536 | 0.9 | 2.505 | 2.784 |
7 | 7.6 | 22.01 | 4.370 | 6.626 | 0.5 | 2.090 | 4.180 |
8 | 8.0 | 22.755 | 4.408 | 6.885 | 0.4 | 0.258 | 0.645 |
9 | 9.1 | 23.219 | 3.945 | 7.045 | 1.1 | 0.161 | 0.145 |