Microporous membrane liquid–liquid extraction technique combined with gas chromatography mass spectrometry for the determination of organotin compounds Original Research Article

A sample clean-up and enrichment method based on microporous membrane liquid–liquid extraction (MMLLE) in a flow system was developed for the determination of organotin (OT) compounds in complex matrices. Ionic OT compounds in the aqueous sample were derivatised off-line using sodium tetraethylborate (NABEt4). Then, the sample solution was pumped through the donor channel of a membrane device holding a hydrophobic microporous membrane. The pores of the membrane and acceptor channel of the device were filled with an organic solvent (isooctane). OT species were extracted into the stagnant acceptor phase. The OT species in these MMLLE extracts were separated and analysed by gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. The detection limits (LODs) (3 × noise) of the method for a 30 ml water sample ranged between 13 and 265 ng l−1 for various OT species.