Automated inline pigment removal for the analysis of pesticide residues in spinach by liquid chromatography tandem mass spectrometry.

An automated inline sample preparation (ILSP) method has been developed for pesticide residue analysis in spinach by LC-MS/MS. Chlorophyll pigments and other matrix constituents were removed from the sample extract using a UHPLC system equipped with an auxiliary pump, 6-port high pressure switching valve, and dual-directional ILSP cartridge containing bonded silica. The new procedure was evaluated as an entirely separate workflow using a simple solid-liquid extraction and as part of a cleanup strategy in conjunction with QuEChERS.