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) 的准确性和灵敏度使得能够通过使用质谱数据库和其他工具来识别候选化合物。然而，鉴定工作流程中的保留时间 (RT) 数据很少使用，因为它可能受到基质或色谱性能的强烈影响。保留时间插值缩放 (RTi) 策略可以提供比 RT 更可靠、更有价值的信息，与分析标准相比，在识别候选化合物方面获得更大的信心。据我们所知，尚未开发出适用于 LC-HRMS 系统的 RTi，可以在正电离或负电离模式下采集时提供信息。

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，这些标准品可以掺入真实样品中，而不会导致可能的假阳性或阴性结果。为了测试 RTi 性能，使用了多种参考标准的混合物，模拟可疑分析物。这些化合物的 RTi 值在溶剂中计算并加标到真实基质中，以评估色谱参数或基质在不同情况下的影响。已经证明，进样量、色谱梯度和进样有机溶剂初始百分比的变化不会显着影响RTi计算。然而，柱老化和柱固定相的固体支持对几种测试化合物的洗脱显示出强烈影响。然而，RTi 允许校正大多数化合物的洗脱变化。此外，RTi 在食品、生物、动物饲料和环境来源的 47 种不同基质中进行了测试。 RTi 在正电离和负电离模式下的应用对于大多数研究的基质显示出总体令人满意的结果。

开发的 RTi 可用于未来的 LC-HRMS 筛选分析，提供额外的参数，从而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。