title: Loop-based multiple heart-cutting two-dimensional liquid chromatography for target analysis in complex matrices.
abstract: Loop-based multiple heart-cutting (MHC) two-dimensional liquid chromatography (2D-LC) is presented as a solution to quantify target components in complex matrices, such as additives in polymers, at very high chromatographic resolution. The determination of hexabromocyclododecane (HBCD) in polystyrene (PS) is described. One dimensional ((1)D) LC analysis with UV detection did not allow quantitation of the main isomers of HBCD due to peak overlap with polymer components. MHC 2D-LC analysis provided the separation power, accuracy, and repeatability needed for quantitative analysis of the additives of interest. Heart-cuts from peaks of the (1)D-chromatogram or entire regions of interest are sampled into loops, where they remain parked until their sequential reinjection onto the second dimension ((2)D) column. A column set consisting of phenyl ((1)D) and C18 ((2)D) stationary phases gave baseline separation in (2)D between HBCD and PS background. Linearity for spiked polymer samples was achieved over a range of 0.02-1.00 wt % HBCD relative to the amount of polymer. The limit of quantitation was estimated at 0.01 wt % HBCD in PS. A peak area RSD of 0.7% obtained for ten replicates of a real sample demonstrated excellent repeatability of the analysis. MHC 2D-LC is an elegant solution for quantitative analyses of difficult-to-separate samples when conventional (1)D separation fails.
authors.affiliation: †Dow Deutschland Anlagengesellschaft mbH, Analytical Technology Center (ATC), Industriestr. 1, 77836 Rheinmuenster, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Pursch
authors.affiliation: ‡Agilent Technologies, Research and Development, Hewlett-Packard-Str. 8, 76337 Waldbronn, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Buckenmaier