The shoot-and-dilute GC technique (split injection) is perfectly matched for the fast sample preparation approach of QuEChERS. The QuEChERS concept provides a fast, multi-residue extraction and “just enough” cleanup. The technique is quick and minimizes solvent usage, but the resulting extract can contain a large amount of coextracted nonvolatile material. A split injection is an advantageous injection technique for dirty samples because less nonvolatile material ends up on the column and the flow through the liner is MUCH faster compared to a splitless injection. Don’t just take my word for it; see these blogs for more information.
Screening fish and other fatty foods for the presence of halogenated flame retardants is important from a human health perspective. While the historical PBDEs have been phased out in the US, some of the newer high-production flame retardants such as those found in Firemaster® 550, do not have any available food occurrence data. In order to develop a screening method for halogenated flame retardants, we paired the fast, multiresidue, sample preparation concept of a modified QuEChERS extraction and a quick extract pass-through of a PSA (primary secondary amine) cleanup cartridge. The PSA pass through removed large fatty acid interferences and the samples were then analyzed using GC-ECD and GC-MS/MS with a 15m x 0.25mm x 0.10µm Rtx-1614 and a 10:1 split injection. Even though we employed a split injection, the sensitive detectors allowed us to detect in the low ng/g range.