The quantification was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The blank blood and urine spiked with SCMs and non-spiked real case (authentic) specimens were incubated at 37 ℃ up to 56 days and at 22, 4 or - 30 ℃ up to 168 days. The non-spiked authentic blood and urine specimens were also stored at - 30 or - 80 ℃ for 1, 3 or 5 years to investigate stabilities during very long time frames.
All the 24 SCMs were much more stable in urine than in blood at 37, 22 or 4 ℃. All 24 SCMs spiked into blood or urine were stable at - 30 ℃ for up to 168 days. The 6 SCMs in the authentic specimens exhibited long stabilities at - 30 or - 80 ℃ for 3-5 years. Some tendencies were observed according to the relation between the structures of SCMs and their stabilities.
The long-term stabilities of 24 SCMs in spiked samples and those of 6 SCMs in the authentic specimens were examined using LC-MS/MS. SCMs were largely very stable and usable several years after storage at - 30 or - 80 ℃.
通过液相色谱-串联质谱(LC-MS/MS)进行定量。将掺有SCM的空白血液和尿液以及未掺和的真实病例(真实)标本在37℃下孵育至56天,在22、4或-30℃下孵育至168天。未加标的真实血液和尿液标本也在-30或-80℃下储存1、3或5年,以研究很长一段时间内的稳定性。
在37、22或4℃下,所有24种SCM在尿液中的稳定性都比在血液中的稳定性高得多。所有24个添加到血液或尿液中的SCM在-30℃下稳定长达168天。真实标本中的6个SCM在-30或-80℃下表现出3-5年的长期稳定性。根据SCM的结构与其稳定性之间的关系观察到一些趋势。
使用LC-MS/MS检查了加标样品中24个SCM和真实样品中6个SCM的长期稳定性。在-30或-80℃下储存几年后,SCM基本上非常稳定和可用。