Table 7 Mass-shift–amino-acid pairs with elevated frequency in stationary phase

+1 Da

N

1

1273/45738 (2.78%)

2260/52371 (4.32%)

2.49×10⁻³⁸

2

1133/31975 (3.54%)

1663/36568 (4.55%)

3.02×10⁻¹¹

3

988/40658 (2.43%)

1313/43285 (3.03%)

8.55×10⁸

+42 Da

S

1

176/585 (30.09%)

322/534 (60.30%)

2.08×10⁻²⁴

2

143/461 (31.02%)

287/509 (56.39%)

2.02×10⁻¹⁵

3

195/597 (32.66%)

269/570 (47.19%)

4.77×10⁻⁰⁷

+42 Da

A

1

55/261 (21.07%)

59/135 (43.70%)

4.15×10⁻⁰⁶

2

55/202 (27.23%)

68/125 (54.40%)

1.22×10⁻⁰⁶

3

38/210 (18.10%)

63/165 (38.18%)

2.08×10⁻⁰⁵

+48 Da

C

1

15/1604 (0.94%)

51/1217 (4.19%)

1.18×10⁻⁰⁸

2

14/1285 (1.09%)

30/770 (3.90%)

4.80×10⁻⁰⁵

3

1/964 (0.10%)

22/707 (3.11%)

6.93×10⁻⁰⁸

+42 Da

T

1

0/244 (0.00%)

57/363 (15.70%)

3.54×10⁻¹⁴

2

5/263 (1.90%)

51/321 (15.89%)

1.31×10⁻⁹

3

11/326 (3.37%)

40/423 (9.46%)

1.11×10⁻³