flow reactor in flame emission and absorption spectrometry, in chromatography

https://dx.doi.org/10.1351/goldbook.F02443
A reactor through which the reactants pass while catalysis is in progress.
Source:
PAC, 1976, 46, 71 (Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis) on page 80