3.2.5. Stability
As shown in Table 2, RA and A1 stabilities in the processed samples have been assessed after freeze-thaw cycles and long-term cold storage at −20 °C for 14 days. The results show that the three analytes can be kept stable for 24 h under the conditions of the autosampler after preparation, 14 days under refrigeration, and through 3 freeze-thaw cycles in plasma samples. Since the concentrations of RA and A1 have not significantly changed, the RA and A1 in plasma should be tested within a specified time under specified storage conditions.