Duration for first extraction | Ξ (mean ± sd) | Number of metabolites (mean ± sd) | |||
---|---|---|---|---|---|
a) Solvents | |||||
1:0 CH3OH:CH2Cl2 | 0 h | 0.74 ± 0.02 | a | 1544 ± 49 | A |
1 day | 0.85 ± 0.03 | b | 1980 ± 47 | B | |
1 week | 0.71 ± 0.02 | c | 574 ± 23 | C | |
3:1 CH3OH:CH2Cl2 | 0 h | 0.78 ± 0.03 | d | 1677 ± 46 | D |
1 day | 0.77 ± 0.02 | d | 647 ± 16 | E | |
1 week | 0.75 ± 0.02 | ade | 602 ± 23 | E | |
2:1 CH3OH:CH2Cl2 | 0 h | 0.83 ± 0.02 | d | 1730 ± 52 | F |
1 day | 0.86 ± 0.05 | bef | 616 ± 13 | CE | |
1 week | 0.72 ± 0.02 | c | 605 ± 12 | CE | |
1:1 CH3OH:CH2Cl2 | 0 h | 0.82 ± 0.03 | g | 1712 ± 52 | DF |
1 day | 0.88 ± 0.01 | f | 2040 ± 20 | G | |
1 week | 0.72 ± 0.01 | ac | 649 ± 25 | E | |
b) pH a | |||||
pH 2 - pH 2 - pH 2 | 0.81 ± 0.06 | abc | 1501 ± 20 | AB | |
pH 2 - pH 6 - pH 9 | 0.85 ± 0.16 | cd | 1509 ± 16 | AB | |
pH 2 - pH 9 - pH 6 | 0.90 ± 0.03 | e | 1513 ± 28 | AB | |
pH 6 - pH 6 - pH 6 | 0.91 ± 0.04 | e | 1538 ± 29 | AB | |
pH 6 - pH 2 - pH 9 | 0.93 ± 0.02 | e | 1545 ± 14 | A | |
pH 6 - pH 9 - pH 2 | 0.89 ± 0.02 | de | 1380 ± 226 | B | |
pH 9 - pH 9 - pH 9 | 0.81 ± 0.26 | bc | 1498 ± 10 | AB | |
pH 9 - pH 2 - pH 6 | 0.80 ± 0.05 | bc | 1510 ± 29 | AB | |
pH 9 - pH 6 - pH 2 | 0.79 ± 0.02 | b | 1505 ± 46 | AB | |
c) Phase separation method of three extraction steps | |||||
A) Extraction in CH3OH:CH2Cl2, H2O added to pooled supernatant (2:1:1) | 0.99 ± 0 | a | 1662 ± 14 | A | |
B) Extraction in CH3OH:CHCl3, H2O added to pooled supernatant (2:1:1) | 0.93 ± 0.02 | b | 1594 ± 20 | B | |
C) Extraction in CH3OH:CH2Cl2, H2O added to every supernatant (2:1:1)b | 0.97 ± 0.01 | a | 1627 ± 18 | AB | |
D) Extraction in CH3OH:CH2Cl2 (2:1), removal of aqueous phase and addition of new solvent mixture after every extraction stepb | 0.97 ± 0 | a | 1656 ± 23 | A | |
d) Storage c | |||||
-80°C | 0.85 ± 0.04 | a | 831 ± 5 | A | |
4°C | 0.91 ± 0.01 | b | 849 ± 25 | A |