Retentiontimebased

Retentiontimebased is a term used to describe analytical approaches and data-processing strategies that use retention time (RT) as the primary discriminant for identifying and quantifying analytes in chromatographic instruments. It is commonly applied in liquid chromatography (HPLC/UHPLC) and gas chromatography (GC), as well as in LC–MS workflows where chromatographic separation precedes detection.

In practice, retention time-based methods rely on established RT libraries or predicted RT models. Analysts match observed peaks to known retention times within defined windows, sometimes complemented by mass spectral data, to assign identities. For quantification, peak areas are integrated at the expected retention times, enabling selective measurement even in complex mixtures. Retention-time windows are often scheduled in targeted acquisition modes to maximize data quality and instrument duty cycles.

Retention times are influenced by multiple factors including column chemistry, mobile phase composition, temperature, flow rate, and sample matrix. To maintain comparability across runs or instruments, methods may employ retention time calibration using internal standards, indexed retention time (iRT) scales, or retention time locking. Data processing commonly includes RT alignment and normalization to correct drift.

Challenges of retention-time-based approaches include retention time drift over time, co-elution of compounds, and library limitations. Robust application often requires careful method transfer or standardization, quality controls, and, when possible, complementary data such as MS fragmentation patterns or retention indices to corroborate identifications.

See also: Chromatography, HPLC, UHPLC, GC, LC-MS, retention index, iRT, RT alignment.