Table 7. Stability of GA in plasma and tissue samples under different storage conditions (n = 6).
| Storage condition | QC (ng/mL) | R.S.D. (%) | |||||
|---|---|---|---|---|---|---|---|
| Plasma | Heart | Liver | Spleen | Lung | Kidney | ||
| Room temperature (25°C) for 24 h | 25.00 | 5.58 | 3.50 | 5.30 | 5.40 | 6.07 | 6.71 |
| 800.00 | 6.81 | 6.03 | 5.90 | 7.23 | 6.89 | 5.87 | |
| 2000.00 | 10.28 | 10.93 | 10.35 | 6.52 | 8.54 | 6.72 | |
| Frozen-thaw cycles at -20°C | 25.00 | 5.73 | 5.28 | 4.66 | 4.01 | 6.17 | 5.20 |
| 800.00 | 7.07 | 5.03 | 5.24 | 7.05 | 8.02 | 7.44 | |
| 2000.00 | 9.70 | 10.57 | 9.01 | 7.68 | 9.17 | 9.07 | |
| Frozen (-20°C) for 1 month | 25.00 | 4.46 | 4.72 | 5.63 | 4.60 | 5.80 | 5.02 |
| 800.00 | 5.10 | 4.23 | 9.10 | 5.06 | 4.73 | 4.82 | |
| 2000.00 | 8.87 | 12.70 | 6.41 | 9.40 | 7.88 | 8.17 | |
Note: R.S.D. (%) = (S.D./mean concentration) *100 %.
Abbreviations: GA, glycyrrhetinic acid; QC, quality control samples; R.S.D., relative standard deviation.