Comprehensive two-dimensional liquid chromatography with on-line Fourier-transform-infrared-spectroscopy detection for the characterization of copolymers.
The on-line coupling of comprehensive two-dimensional liquid chromatography (liquid chromatography x size-exclusion chromatography, LC x SEC) and infrared (IR) spectroscopy has been realized by means of an IR flow cell. The system has been assessed by the functional-group analysis of a series of styrene-methylacrylate (SMA) copolymers with varying styrene content. Ultraviolet (UV) detection was used as a detection technique to verify the detection with IR. The LC x SEC-IR functional-group contour plots (comprehensive chromatograms) obtained for styrene were in agreement with the contour plots constructed from the UV signal. In addition, contour plots can be obtained from non-UV-active groups. One such plot, for the carbonyl-stretching vibration of methylacrylate (MA), is shown. Selective detection of MA proved possible using flow cell IR detection. The combination of the contour plots for styrene and MA allowed a full characterization of the copolymer and it was revealed that the present series of SMA copolymers exhibited homogeneous chemical-composition distributions (CCDs). In addition, commercially available fast-SEC columns have been assessed in this study with respect to their potential to serve as second-dimension separation columns.
Kok
S J
SJ
TNO Nutrition and Food Research, Packaging Research Department, Utrechtseweg 48, 3704 HE Zeist, The Netherlands. sander.kok@ge.com
Hankemeier
Th
T
Schoenmakers
P J
PJ
D000179:Acrylates / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D011108:Polymers / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013343:Styrenes / Q000737:chemistry
D000179:Acrylates; D011108:Polymers; D012997:Solvents; D013343:Styrenes