Online coupling of size-exclusion chromatography and IR spectroscopy to correlate molecular weight with chemical composition.
The determination of molecular weight and correlated chemical composition is of major interest for the advanced analysis of copolymers, blends, or unknown samples. In this work, we present a new way of online coupling IR spectroscopy and SEC to achieve a chemically sensitive, universally applicable SEC detector. Our method overcomes the limitations of existing spectroscopy-SEC combinations. We solved the major problems, like huge intensity of solvent signals (polymer concentration in detector <1 g L(-1) ) and short measuring time (<30 s), by recording the IR spectra with fully optimized sensitivity and by following mathematical solvent suppression. The measuring time for a certain S/N was reduced in several optimization steps by a factor of more than 70 000. The resulting sensitivity allows online coupled IR-SEC measurements.
Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 18,Karlsruhe, Germany.
Timo F
TF
Beskers
Thorsten
T
Hofe
Manfred
M
Wilhelm
D000042:Absorption; D002245:Carbon Dioxide / Q000737:chemistry; D002850:Chromatography, Gel; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
D011108:Polymers; D012997:Solvents; D014867:Water; D002245:Carbon Dioxide