Figure 7-21. Second dimension (2D) chromatograms showing the change in peak shape observed for the 2D column after 2 h of continuous LC x LC operation (360 cycles) using an electrically actuated 10-port/2-position valve in the interface. The sample injection occurred at 120 s relative to the start of the LC x LC separation (2.0-2.33 min). Panel A shows the initial performance of the column during the very first LC x LC separation, and Panel B shows the performance of the same column after 2 h of use. The probe compounds are (1) nitropropane, (2) nitropentane, and (3) dipropyl phthalate. All of the 2D columns used in this work were 30 mm x 2.1 mm i.d., packed with sub-three micron particles with a C18 stationary phase.
Reprinted with permission from Talus, E.S., Witt, K.E., Stoll, D.R., 2015. Effect of pressure pulses at the interface valve on the stability of second dimension columns in online comprehensive two-dimensional liquid chromatography. J. Chromatogr. A 1378, 50-57. http://dx.doi.org/10.1016/j.chroma.2014.12.019. Copyright 2015, Elsevier.
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