The accuracy and sensitivity of high resolution mass spectrometry (HRMS) enables the identification of candidate compounds with the use of mass spectrometric databases among other tools. However, retention time (RT) data in identification workflows has been sparingly used since it could be strongly affected by matrix or chromatographic performance. Retention Time Interpolation scaling (RTi) strategies can provide a more robust and valuable information than RT, gaining more confidence in the identification of candidate compounds in comparison to an analytical standard. Up to our knowledge, no RTi has been developed for LC-HRMS systems providing information when acquiring in either positive or negative ionization modes.

In this work, an RTi strategy was developed by means of the use of 16 isotopically labelled reference standards, which can be spiked into a real sample without resulting in possible false positives or negatives. For testing the RTi performance, a mixture of several reference standards, emulating suspect analytes, were used. RTi values for these compounds were calculated both in solvent and spiked in a real matrix to assess the effect of either chromatographic parameters or matrix in different scenarios. It has been demonstrated that the variation of injection volume, chromatographic gradient and initial percentage of organic solvent injected does not considerably affect RTi calculation. Column aging and solid support of the stationary phase of the column, however, showed strong effects on the elution of several test compounds. Yet, RTi permitted the correction of elution shifts of most compounds. Furthermore, RTi was tested in 47 different matrices from food, biological, animal feeding and environmental origin. The application of RTi in both positive and negative ionization modes showed in general satisfactory results for most matrices studied.

The RTi developed can be used in future LC-HRMS screening analysis giving an additional parameter, which facilitates tedious processing tasks and gain more confidence in the identification of (non)-suspect analytes.

高分辨率质谱（HRMS）的准确性和灵敏性使得可以通过使用质谱数据库以及其他工具来鉴定候选化合物。但是，由于可能会受到基质或色谱性能的强烈影响，因此很少使用识别工作流程中的保留时间（RT）数据。保留时间插值缩放（RTi）策略可以提供比RT更健壮和有价值的信息，与分析标准相比，在确定候选化合物方面更具信心。据我们所知，尚未开发出可用于LC-HRMS系统的RTi，当以正电离或负电离模式进行采集时，RTi均无法提供信息。

在这项工作中，通过使用16种同位素标记的参考标准品开发了RTi策略，可以将其加标到真实样品中，而不会导致假阳性或阴性。为了测试RTi性能，使用了几种参考标准品的混合物，模拟可疑分析物。这些化合物的RTi值既可以在溶剂中计算，也可以在真实基质中加标，以评估色谱参数或基质在不同情况下的效果。已经证明，进样量，色谱梯度和所进样的有机溶剂的初始百分比的变化不会显着影响RTi的计算。但是，色谱柱老化和色谱柱固定相的固相载体对几种测试化合物的洗脱显示出强烈的影响。然而，RTi允许校正大多数化合物的洗脱位移。此外，RTi在来自食品，生物，动物饲养和环境的47种不同基质中进行了测试。对于大多数研究的基质，RTi在正电离和负电离模式下的应用均显示令人满意的结果。

所开发的RTi可用于未来的LC-HRMS筛选分析中，并提供一个附加参数，该参数可简化繁琐的处理任务并在识别（非）可疑分析物时获得更大的信心。