A modified QuEChERS approach for the screening of dioxins and furans in sediments.

Abstract

A rapid extraction and cleanup method for the screening of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments is described which combines a modified QuEChERS extraction with carbon reversed-phase solid phase extraction cleanup. This approach is compared to the classical Soxhlet extraction and multi-column cleanup method in terms of toxic equivalence quotients (TEQs), precision, instrumental chromatography, method detection limits (MDLs), recovery of (13)C-labelled quantitation standard, sample preparation time, workload capacity, and sustainability factors. TEQs of 32 sediment samples were found to be well correlated and differed by 16 ± 10% between the two methods. Certified and standard reference sediments differed by 4.1 and 6.7%, respectively. Precision and instrumental chromatography were comparable. While the modified QuEChERS method had higher MDLs and lower recoveries, in terms of preparation time and workload capacity, the modified QuEChERS approach can prepare approximately 30 samples per day as compared to 10-20 samples in 3 to 4days for the classic method. The modified QuEChERS method was also found to be safer and greener. The appreciable improvement in capacity makes the modified QuEChERS approach a suitable alternative to the classical method for applications where turnaround time and the number of samples that can be analyzed are more important than minimal detection limits. Graphical Abstract Created using Microsoft Paint for Windows 7 Professional A bar graph with the structures of dioxins and furans on the x axis shows agreement between two sets of data. A legend labels the first set of data as Soxhlet. The Soxhlet set is illustrated as four days crossed off of a calendar page, a Soxhlet extractor, and several packed chromatography columns. The legend identifies the second set of data as QuEChERS. The QuEChERS set is represented by a clock face marked with twenty four hours, two centrifuge tubes containing the sediment and reagents before and after salting out, and a carbon column attached to a reservoir.