A GC-MS study of the stability of rat serum metabolome during the sample preparation procedure
In GC-MS-based metabolomic analysis of serum samples, differential sample handling and storage can induce systematic bias hiding the original metabolic state. Here, several sample sets were examined to characterize the effects of several potential sources of bias. These factors were the thawing temperature (4 °C and 25 °C) and time (0.5–24 h) of the primary sample, storage temperature (4 °C and 25 °C) and time (0–48 h) of the nitrogen dried sample, storage temperature (4 °C and 25 °C), time (0–48 h) and refrigerating/warming cycle of the derivatized sample. The results showed that the primary sample thawed at both 4 °C and 25 °C for up to 24 h appeared to be stable. The storage of nitrogen dried samples and derivatized samples at 4 °C for up to 48 h still provided useable samples. However, the nitrogen dried samples denatured after 24 h storage at 25 °C. And the derivatized samples apparently changed after 10 h storage at 25 °C, or after undergoing two refrigerating/warming cycles.