Separation of Aquatic Lipid Classes by Chromarod Thin-Layer Chromatography with Measurement by latroscan Flame Ionization Detection

Abstract

Lipid classes in solvent extracts of marine dissolved and particulate matter, benthic invertebrates, net-caught zooplankton, and freshwater sediment trap material were measured with the Chromarod–latroscan (thin-layer chromatography (TLC/flame ionization detector (FID)) system. As many as 11 classes were identified in these samples by combining multiple development schemes with the partial scanning facility in the latroscan. Part of the latroscan's circuitry was modified to include a scan-interruptor switch to further facilitate partial scanning. Quantitative aspects of the TLC/FID system were improved with the use of a syringe fitted with a repeating dispenser for sample application, and by maximizing the detector's response. High FID responses were obtained with double developments and high hydrogen flow rates and FID scan rates. Under these conditions an analytical precision of 10% was attained for most compounds with only about five analyses on different Chromarods, and the range in mean FID response to different compounds was significantly narrowed. An intercalibration was performed to test TLC/FID accuracy: the latroscan gave lipid values which were about 85% of true gravimetric values.