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A test reaction for rapid‐mixing, rapid‐flow Raman cells
Author(s) -
Cartier L. R. Sans,
Storer A. C.,
Carey P. R.
Publication year - 1988
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250190208
Subject(s) - raman spectroscopy , mixing (physics) , chemistry , volumetric flow rate , analytical chemistry (journal) , flow (mathematics) , methanol , materials science , thermodynamics , mechanics , chromatography , optics , organic chemistry , physics , quantum mechanics
The design and construction of a four‐jet rapid‐mixing, rapid‐flow Raman cell, suitable for following chemical or biochemical reaction events 20 ms and longer after mixing, is described. A suitable test reaction, the base‐catalysed hydrolysis of 2,4‐dinitrophenyl acetate in 10% methanol, has been characterized by a stopped‐flow kinetic analysis. When this reaction is carried out in the rapid‐mixing, rapid‐flow Raman cell a resonance Raman peak of the 2,4‐dinitrophenolate product, measured against a methanol peak as an internal standard, permits the calculation of the extent of product formation. Using the rate constant determined from the stopped‐flow kinetic analysis, the dead time (the time after mixing) in the Raman flow cell can be calculated for the flow‐rate employed. When the flow system is operating correctly, this dead time is in close agreement with that calculated from the known flow‐rate and the combined volume of the mixing and flow cell. Since the reaction is monitored using the commonly available 457.9 nm Ar + line, it can be used to test the operational efficiency of rapid‐mixing, rapid‐flow systems built in most Raman laboratories.